From 9827b638b4d1a8f3b36fd3e64a46563927c0b326 Mon Sep 17 00:00:00 2001
From: Ryan Cavanaugh <RyanCavanaugh@users.noreply.github.com>
Date: Fri, 10 Jun 2016 15:44:11 -0700
Subject: [PATCH 1/7] Implicit type inclusion changes

---
 src/compiler/commandLineParser.ts             |  8 +-
 src/compiler/diagnosticMessages.json          |  4 +
 src/compiler/program.ts                       | 96 +++++++++----------
 src/compiler/types.ts                         |  7 +-
 src/harness/fourslash.ts                      |  4 +-
 src/harness/harness.ts                        | 59 ++++++++----
 src/harness/harnessLanguageService.ts         | 21 ++--
 src/harness/projectsRunner.ts                 |  3 +-
 src/server/editorServices.ts                  |  4 +
 src/services/services.ts                      | 10 +-
 tests/baselines/reference/commonSourceDir5.js |  1 +
 .../reference/commonSourceDir5.symbols        |  9 +-
 .../reference/commonSourceDir5.types          |  1 +
 .../reference/library-reference-1.symbols     |  4 +-
 .../reference/library-reference-1.trace.json  | 15 ++-
 .../reference/library-reference-1.types       |  4 +-
 .../reference/library-reference-10.symbols    |  4 +-
 .../reference/library-reference-10.trace.json | 18 ++--
 .../reference/library-reference-10.types      |  4 +-
 .../reference/library-reference-11.trace.json | 14 +--
 .../reference/library-reference-12.trace.json | 14 +--
 .../reference/library-reference-13.trace.json |  4 +-
 .../reference/library-reference-14.trace.json |  4 +-
 .../reference/library-reference-15.errors.txt | 14 +--
 .../reference/library-reference-15.js         | 11 ++-
 .../reference/library-reference-15.trace.json | 27 +-----
 .../reference/library-reference-2.trace.json  | 10 +-
 .../reference/library-reference-3.trace.json  | 15 +--
 .../reference/library-reference-4.trace.json  | 48 +++-------
 .../reference/library-reference-5.trace.json  | 78 ++++++++-------
 .../reference/library-reference-6.symbols     | 16 ----
 .../reference/library-reference-6.trace.json  | 31 +++++-
 .../reference/library-reference-6.types       | 16 ----
 .../reference/library-reference-7.trace.json  | 14 +--
 .../reference/library-reference-8.symbols     |  6 +-
 .../reference/library-reference-8.trace.json  | 50 ++++++----
 .../reference/library-reference-8.types       |  6 +-
 .../reference/library-reference-9.js          | 16 ----
 .../reference/library-reference-9.symbols     | 16 ----
 .../reference/library-reference-9.trace.json  |  7 --
 .../reference/library-reference-9.types       | 16 ----
 .../moduleResolutionWithSymlinks.errors.txt   | 21 ++++
 .../moduleResolutionWithSymlinks.symbols      | 36 -------
 .../moduleResolutionWithSymlinks.trace.json   | 42 +++++++-
 .../moduleResolutionWithSymlinks.types        | 38 --------
 ...pingBasedModuleResolution3_node.trace.json |  3 +
 ...pingBasedModuleResolution4_node.trace.json |  3 +
 ...pingBasedModuleResolution5_node.trace.json |  4 +
 ...pingBasedModuleResolution6_node.trace.json |  2 +
 ...pingBasedModuleResolution7_node.trace.json |  5 +
 .../typeReferenceDirectives1.trace.json       |  9 +-
 .../typeReferenceDirectives10.trace.json      | 12 ++-
 .../typeReferenceDirectives11.trace.json      |  5 +-
 .../typeReferenceDirectives12.trace.json      | 14 ++-
 .../typeReferenceDirectives13.trace.json      | 12 ++-
 .../typeReferenceDirectives2.trace.json       |  4 +-
 .../typeReferenceDirectives3.trace.json       |  9 +-
 .../typeReferenceDirectives4.trace.json       |  9 +-
 .../typeReferenceDirectives5.trace.json       | 12 ++-
 .../typeReferenceDirectives6.trace.json       |  9 +-
 .../typeReferenceDirectives7.trace.json       |  9 +-
 .../typeReferenceDirectives8.trace.json       |  5 +-
 .../typeReferenceDirectives9.trace.json       | 14 ++-
 tests/baselines/reference/typingsLookup1.js   |  2 +
 .../reference/typingsLookup1.symbols          |  5 +-
 .../reference/typingsLookup1.trace.json       | 18 ++++
 .../baselines/reference/typingsLookup1.types  |  5 +-
 tests/cases/compiler/commonSourceDir5.ts      |  1 +
 .../compiler/typeReferenceDirectives1.ts      |  2 +-
 .../compiler/typeReferenceDirectives10.ts     |  2 +-
 .../compiler/typeReferenceDirectives11.ts     |  2 +-
 .../compiler/typeReferenceDirectives12.ts     |  2 +-
 .../compiler/typeReferenceDirectives13.ts     |  2 +-
 .../compiler/typeReferenceDirectives2.ts      |  2 +-
 .../compiler/typeReferenceDirectives3.ts      |  2 +-
 .../compiler/typeReferenceDirectives4.ts      |  2 +-
 .../compiler/typeReferenceDirectives5.ts      |  2 +-
 .../compiler/typeReferenceDirectives6.ts      |  2 +-
 .../compiler/typeReferenceDirectives7.ts      |  2 +-
 .../compiler/typeReferenceDirectives8.ts      |  2 +-
 .../compiler/typeReferenceDirectives9.ts      |  2 +-
 .../references/library-reference-1.ts         |  7 +-
 .../references/library-reference-10.ts        |  9 +-
 .../references/library-reference-13.ts        |  3 +-
 .../references/library-reference-14.ts        |  3 +-
 .../references/library-reference-15.ts        |  8 +-
 .../references/library-reference-2.ts         |  3 +-
 .../references/library-reference-3.ts         |  2 +-
 .../references/library-reference-4.ts         |  3 +-
 .../references/library-reference-5.ts         |  1 +
 .../references/library-reference-6.ts         |  6 +-
 .../references/library-reference-8.ts         |  9 +-
 .../references/library-reference-9.ts         | 20 ----
 .../conformance/typings/typingsLookup1.ts     |  8 +-
 .../goToDefinitionTypeReferenceDirective.ts   |  2 +-
 .../goToDefinitionTypeReferenceDirective.ts   |  2 +-
 .../goToDefinitionTypeReferenceDirective.ts   |  4 +-
 tests/cases/unittests/moduleResolution.ts     | 29 +++---
 .../cases/unittests/reuseProgramStructure.ts  |  5 +-
 99 files changed, 605 insertions(+), 562 deletions(-)
 delete mode 100644 tests/baselines/reference/library-reference-6.symbols
 delete mode 100644 tests/baselines/reference/library-reference-6.types
 delete mode 100644 tests/baselines/reference/library-reference-9.js
 delete mode 100644 tests/baselines/reference/library-reference-9.symbols
 delete mode 100644 tests/baselines/reference/library-reference-9.trace.json
 delete mode 100644 tests/baselines/reference/library-reference-9.types
 create mode 100644 tests/baselines/reference/moduleResolutionWithSymlinks.errors.txt
 delete mode 100644 tests/baselines/reference/moduleResolutionWithSymlinks.symbols
 delete mode 100644 tests/baselines/reference/moduleResolutionWithSymlinks.types
 create mode 100644 tests/baselines/reference/typingsLookup1.trace.json
 delete mode 100644 tests/cases/conformance/references/library-reference-9.ts

diff --git a/src/compiler/commandLineParser.ts b/src/compiler/commandLineParser.ts
index 506a2d5bee42d..a79d365fdd464 100644
--- a/src/compiler/commandLineParser.ts
+++ b/src/compiler/commandLineParser.ts
@@ -337,8 +337,12 @@ namespace ts {
             }
         },
         {
-            name: "typesRoot",
-            type: "string"
+            name: "typeRoots",
+            type: "list",
+            element: {
+                name: "typeRoots",
+                type: "string"
+            }            
         },
         {
             name: "types",
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 034bd27b1472a..c7052cf71fe0f 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -1935,6 +1935,10 @@
         "category": "Error",
         "code": 2687
     },
+    "Cannot find type definition file for '{0}'.": {
+        "category": "Error",
+        "code": 2688
+    },
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",
         "code": 4000
diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index bab554927e726..f7750e43002e8 100644
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -9,16 +9,11 @@ namespace ts {
     /* @internal */ export let ioWriteTime = 0;
 
     /** The version of the TypeScript compiler release */
+    export const version = "1.9.0";
 
     const emptyArray: any[] = [];
 
-    const defaultLibrarySearchPaths = [
-        "types/",
-        "node_modules/",
-        "node_modules/@types/",
-    ];
-
-    export const version = "1.9.0";
+    const defaultTypeRoots = ["node_modules/@types"];
 
     export function findConfigFile(searchPath: string, fileExists: (fileName: string) => boolean): string {
         while (true) {
@@ -196,24 +191,22 @@ namespace ts {
             traceEnabled
         };
 
-        // use typesRoot and fallback to directory that contains tsconfig or current directory if typesRoot is not set
-        const rootDir = options.typesRoot || (options.configFilePath ? getDirectoryPath(options.configFilePath) : (host.getCurrentDirectory && host.getCurrentDirectory()));
-
+        const typeRoots = options.typeRoots || defaultTypeRoots;
         if (traceEnabled) {
             if (containingFile === undefined) {
-                if (rootDir === undefined) {
+                if (typeRoots === undefined) {
                     trace(host, Diagnostics.Resolving_type_reference_directive_0_containing_file_not_set_root_directory_not_set, typeReferenceDirectiveName);
                 }
                 else {
-                    trace(host, Diagnostics.Resolving_type_reference_directive_0_containing_file_not_set_root_directory_1, typeReferenceDirectiveName, rootDir);
+                    trace(host, Diagnostics.Resolving_type_reference_directive_0_containing_file_not_set_root_directory_1, typeReferenceDirectiveName, typeRoots);
                 }
             }
             else {
-                if (rootDir === undefined) {
+                if (typeRoots === undefined) {
                     trace(host, Diagnostics.Resolving_type_reference_directive_0_containing_file_1_root_directory_not_set, typeReferenceDirectiveName, containingFile);
                 }
                 else {
-                    trace(host, Diagnostics.Resolving_type_reference_directive_0_containing_file_1_root_directory_2, typeReferenceDirectiveName, containingFile, rootDir);
+                    trace(host, Diagnostics.Resolving_type_reference_directive_0_containing_file_1_root_directory_2, typeReferenceDirectiveName, containingFile, typeRoots);
                 }
             }
         }
@@ -221,14 +214,13 @@ namespace ts {
         const failedLookupLocations: string[] = [];
 
         // Check primary library paths
-        if (rootDir !== undefined) {
-            const effectivePrimarySearchPaths = options.typesSearchPaths || defaultLibrarySearchPaths;
-            for (const searchPath of effectivePrimarySearchPaths) {
-                const primaryPath = combinePaths(rootDir, searchPath);
-                if (traceEnabled) {
-                    trace(host, Diagnostics.Resolving_with_primary_search_path_0, primaryPath);
-                }
-                const candidate = combinePaths(primaryPath, typeReferenceDirectiveName);
+        if (typeRoots.length) {
+            if (traceEnabled) {
+                trace(host, Diagnostics.Resolving_with_primary_search_path_0, typeRoots.join(', '));
+            }
+            const primarySearchPaths = options.typeRoots || defaultTypeRoots;
+            for (const typeRoot of primarySearchPaths) {
+                const candidate = combinePaths(typeRoot, typeReferenceDirectiveName);
                 const candidateDirectory = getDirectoryPath(candidate);
                 const resolvedFile = loadNodeModuleFromDirectory(typeReferenceExtensions, candidate, failedLookupLocations,
                     !directoryProbablyExists(candidateDirectory, host), moduleResolutionState);
@@ -255,9 +247,6 @@ namespace ts {
         if (containingFile) {
             initialLocationForSecondaryLookup = getDirectoryPath(containingFile);
         }
-        else {
-            initialLocationForSecondaryLookup = rootDir;
-        }
 
         if (initialLocationForSecondaryLookup !== undefined) {
             // check secondary locations
@@ -875,19 +864,6 @@ namespace ts {
             }
         }
 
-        function getDefaultTypeDirectiveNames(rootPath: string): string[] {
-            const localTypes = combinePaths(rootPath, "types");
-            const npmTypes = combinePaths(rootPath, "node_modules/@types");
-            let result: string[] = [];
-            if (sys.directoryExists(localTypes)) {
-                result = result.concat(sys.getDirectories(localTypes));
-            }
-            if (sys.directoryExists(npmTypes)) {
-                result = result.concat(sys.getDirectories(npmTypes));
-            }
-            return result;
-        }
-
         function getDefaultLibLocation(): string {
             return getDirectoryPath(normalizePath(sys.getExecutingFilePath()));
         }
@@ -896,7 +872,6 @@ namespace ts {
         const realpath = sys.realpath && ((path: string) => sys.realpath(path));
 
         return {
-            getDefaultTypeDirectiveNames,
             getSourceFile,
             getDefaultLibLocation,
             getDefaultLibFileName: options => combinePaths(getDefaultLibLocation(), getDefaultLibFileName(options)),
@@ -909,6 +884,7 @@ namespace ts {
             readFile: fileName => sys.readFile(fileName),
             trace: (s: string) => sys.write(s + newLine),
             directoryExists: directoryName => sys.directoryExists(directoryName),
+            getDirectories: (path: string) => sys.getDirectories(path),
             realpath
         };
     }
@@ -972,21 +948,34 @@ namespace ts {
         return resolutions;
     }
 
-    export function getDefaultTypeDirectiveNames(options: CompilerOptions, rootFiles: string[], host: CompilerHost): string[] {
+    function getInferredTypesRoot(options: CompilerOptions, rootFiles: string[], host: CompilerHost) {
+        return computeCommonSourceDirectoryOfFilenames(rootFiles, host.getCurrentDirectory(), f => host.getCanonicalFileName(f));
+    }
+
+    /**
+      * Given a set of options and a set of root files, returns the set of type directive names
+      *   that should be included for this program automatically.
+      * This list could either come from the config file,
+      *   or from enumerating the types root + initial secondary types lookup location.
+      * More type directives might appear in the program later as a result of loading actual source files;
+      *   this list is only the set of defaults that are implicitly included.
+      */
+    export function getAutomaticTypeDirectiveNames(options: CompilerOptions, rootFiles: string[], host: CompilerHost): string[] {
         // Use explicit type list from tsconfig.json
         if (options.types) {
             return options.types;
         }
 
-        // or load all types from the automatic type import fields
-        if (host && host.getDefaultTypeDirectiveNames) {
-            const commonRoot = computeCommonSourceDirectoryOfFilenames(rootFiles, host.getCurrentDirectory(), f => host.getCanonicalFileName(f));
-            if (commonRoot) {
-                return host.getDefaultTypeDirectiveNames(commonRoot);
+        // Walk the primary type lookup locations
+        let result: string[] = [];
+        if (host.directoryExists && host.getDirectories) {
+            for (const root of options.typeRoots || defaultTypeRoots) {
+                if (host.directoryExists(root)) {
+                    result = result.concat(host.getDirectories(root));
+                }
             }
         }
-
-        return undefined;
+        return result;
     }
 
     export function createProgram(rootNames: string[], options: CompilerOptions, host?: CompilerHost, oldProgram?: Program): Program {
@@ -1038,11 +1027,13 @@ namespace ts {
         if (!tryReuseStructureFromOldProgram()) {
             forEach(rootNames, name => processRootFile(name, /*isDefaultLib*/ false));
 
-            // load type declarations specified via 'types' argument
-            const typeReferences: string[] = getDefaultTypeDirectiveNames(options, rootNames, host);
+            // load type declarations specified via 'types' argument or implicitly from types/ and node_modules/@types folders
+            const typeReferences: string[] = getAutomaticTypeDirectiveNames(options, rootNames, host);
 
             if (typeReferences) {
-                const resolutions = resolveTypeReferenceDirectiveNamesWorker(typeReferences, /*containingFile*/ undefined);
+                const inferredRoot = getInferredTypesRoot(options, rootNames, host);
+                const containingFilename = combinePaths(inferredRoot, "__inferred type names__.ts");
+                const resolutions = resolveTypeReferenceDirectiveNamesWorker(typeReferences, containingFilename);
                 for (let i = 0; i < typeReferences.length; i++) {
                     processTypeReferenceDirective(typeReferences[i], resolutions[i]);
                 }
@@ -1149,10 +1140,9 @@ namespace ts {
                 (oldOptions.jsx !== options.jsx) ||
                 (oldOptions.allowJs !== options.allowJs) ||
                 (oldOptions.rootDir !== options.rootDir) ||
-                (oldOptions.typesSearchPaths !== options.typesSearchPaths) ||
                 (oldOptions.configFilePath !== options.configFilePath) ||
                 (oldOptions.baseUrl !== options.baseUrl) ||
-                (oldOptions.typesRoot !== options.typesRoot) ||
+                (oldOptions.typeRoots !== options.typeRoots) ||
                 !arrayIsEqualTo(oldOptions.rootDirs, options.rootDirs) ||
                 !mapIsEqualTo(oldOptions.paths, options.paths)) {
                 return false;
@@ -1904,7 +1894,7 @@ namespace ts {
                 }
             }
             else {
-                fileProcessingDiagnostics.add(createDiagnostic(refFile, refPos, refEnd, Diagnostics.Cannot_find_name_0, typeReferenceDirective));
+                fileProcessingDiagnostics.add(createDiagnostic(refFile, refPos, refEnd, Diagnostics.Cannot_find_type_definition_file_for_0, typeReferenceDirective));
             }
 
             if (saveResolution) {
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index a86b1ed708d9f..7f53ac29eaf1f 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -2496,7 +2496,6 @@ namespace ts {
         jsx?: JsxEmit;
         reactNamespace?: string;
         listFiles?: boolean;
-        typesSearchPaths?: string[];
         locale?: string;
         mapRoot?: string;
         module?: ModuleKind;
@@ -2555,8 +2554,8 @@ namespace ts {
         // When options come from a config file, its path is recorded here
         configFilePath?: string;
         /* @internal */
-        // Path used to used to compute primary search locations
-        typesRoot?: string;
+        // Paths used to used to compute primary types search locations
+        typeRoots?: string[];
         types?: string[];
 
         list?: string[];
@@ -2861,9 +2860,9 @@ namespace ts {
         getCancellationToken?(): CancellationToken;
         getDefaultLibFileName(options: CompilerOptions): string;
         getDefaultLibLocation?(): string;
-        getDefaultTypeDirectiveNames?(rootPath: string): string[];
         writeFile: WriteFileCallback;
         getCurrentDirectory(): string;
+        getDirectories(path: string): string[];
         getCanonicalFileName(fileName: string): string;
         useCaseSensitiveFileNames(): boolean;
         getNewLine(): string;
diff --git a/src/harness/fourslash.ts b/src/harness/fourslash.ts
index c05fca5bb472a..8104f11339223 100644
--- a/src/harness/fourslash.ts
+++ b/src/harness/fourslash.ts
@@ -246,8 +246,8 @@ namespace FourSlash {
             // Create a new Services Adapter
             this.cancellationToken = new TestCancellationToken();
             const compilationOptions = convertGlobalOptionsToCompilerOptions(this.testData.globalOptions);
-            if (compilationOptions.typesRoot) {
-                compilationOptions.typesRoot = ts.getNormalizedAbsolutePath(compilationOptions.typesRoot, this.basePath);
+            if (compilationOptions.typeRoots) {
+                compilationOptions.typeRoots = compilationOptions.typeRoots.map(p => ts.getNormalizedAbsolutePath(p, this.basePath));
             }
 
             const languageServiceAdapter = this.getLanguageServiceAdapter(testType, this.cancellationToken, compilationOptions);
diff --git a/src/harness/harness.ts b/src/harness/harness.ts
index 5fe5b84ac9148..37066abd9bdf7 100644
--- a/src/harness/harness.ts
+++ b/src/harness/harness.ts
@@ -432,6 +432,7 @@ namespace Harness {
         readFile(path: string): string;
         writeFile(path: string, contents: string): void;
         directoryName(path: string): string;
+        getDirectories(path: string): string[];
         createDirectory(path: string): void;
         fileExists(fileName: string): boolean;
         directoryExists(path: string): boolean;
@@ -477,6 +478,7 @@ namespace Harness {
             export const readFile: typeof IO.readFile = path => ts.sys.readFile(path);
             export const writeFile: typeof IO.writeFile = (path, content) => ts.sys.writeFile(path, content);
             export const directoryName: typeof IO.directoryName = fso.GetParentFolderName;
+            export const getDirectories: typeof IO.getDirectories = dir => ts.sys.getDirectories(dir);
             export const directoryExists: typeof IO.directoryExists = fso.FolderExists;
             export const fileExists: typeof IO.fileExists = fso.FileExists;
             export const log: typeof IO.log = global.WScript && global.WScript.StdOut.WriteLine;
@@ -543,6 +545,7 @@ namespace Harness {
             export const args = () => ts.sys.args;
             export const getExecutingFilePath = () => ts.sys.getExecutingFilePath();
             export const exit = (exitCode: number) => ts.sys.exit(exitCode);
+            export const getDirectories: typeof IO.getDirectories = path => ts.sys.getDirectories(path);
 
             export const readFile: typeof IO.readFile = path => ts.sys.readFile(path);
             export const writeFile: typeof IO.writeFile = (path, content) => ts.sys.writeFile(path, content);
@@ -616,6 +619,7 @@ namespace Harness {
             export const args = () => <string[]>[];
             export const getExecutingFilePath = () => "";
             export const exit = (exitCode: number) => { };
+            export const getDirectories = () => <string[]>[];
 
             export let log = (s: string) => console.log(s);
 
@@ -861,7 +865,7 @@ namespace Harness {
             // Local get canonical file name function, that depends on passed in parameter for useCaseSensitiveFileNames
             const getCanonicalFileName = ts.createGetCanonicalFileName(useCaseSensitiveFileNames);
 
-            let realPathMap: ts.FileMap<string>;
+            const realPathMap: ts.FileMap<string> = ts.createFileMap<string>();
             const fileMap: ts.FileMap<() => ts.SourceFile> = ts.createFileMap<() => ts.SourceFile>();
             for (const file of inputFiles) {
                 if (file.content !== undefined) {
@@ -870,9 +874,6 @@ namespace Harness {
                     if (file.fileOptions && file.fileOptions["symlink"]) {
                         const link = file.fileOptions["symlink"];
                         const linkPath = ts.toPath(link, currentDirectory, getCanonicalFileName);
-                        if (!realPathMap) {
-                            realPathMap = ts.createFileMap<string>();
-                        }
                         realPathMap.set(linkPath, fileName);
                         fileMap.set(path, (): ts.SourceFile => { throw new Error("Symlinks should always be resolved to a realpath first"); });
                     }
@@ -906,20 +907,6 @@ namespace Harness {
 
 
             return {
-                getDefaultTypeDirectiveNames: (path: string) => {
-                    const results: string[] = [];
-                    fileMap.forEachValue((key, value) => {
-                        const rx = /node_modules\/@types\/(\w+)/;
-                        const typeNameResult = rx.exec(key);
-                        if (typeNameResult) {
-                            const typeName = typeNameResult[1];
-                            if (results.indexOf(typeName) < 0) {
-                                results.push(typeName);
-                            }
-                        }
-                    });
-                    return results;
-                },
                 getCurrentDirectory: () => currentDirectory,
                 getSourceFile,
                 getDefaultLibFileName,
@@ -937,7 +924,37 @@ namespace Harness {
                 realpath: realPathMap && ((f: string) => {
                     const path = ts.toPath(f, currentDirectory, getCanonicalFileName);
                     return realPathMap.contains(path) ? realPathMap.get(path) : path;
-                })
+                }),
+                directoryExists: dir => {
+                    let path = ts.toPath(dir, currentDirectory, getCanonicalFileName);
+                    // Strip trailing /, which may exist if the path is a drive root
+                    if (path[path.length - 1] === "/") {
+                        path = <ts.Path>path.substr(0, path.length - 1);
+                    }
+                    let exists = false;
+                    fileMap.forEachValue(key => {
+                        if (key.indexOf(path) === 0 && key[path.length] === "/") {
+                            exists = true;
+                        }
+                    });
+                    return exists;
+                },
+                getDirectories: d => {
+                    const path = ts.toPath(d, currentDirectory, getCanonicalFileName);
+                    const result: string[] = [];
+                    fileMap.forEachValue((key, value) => {
+                        if (key.indexOf(path) === 0 && key.lastIndexOf("/") > path.length) {
+                            let dirName = key.substr(path.length, key.indexOf("/", path.length + 1) - path.length);
+                            if (dirName[0] === "/") {
+                                dirName = dirName.substr(1);
+                            }
+                            if (result.indexOf(dirName) < 0) {
+                                result.push(dirName);
+                            }
+                        }
+                    });
+                    return result;
+                }
             };
         }
 
@@ -1036,7 +1053,9 @@ namespace Harness {
             options.noErrorTruncation = true;
             options.skipDefaultLibCheck = true;
 
-            currentDirectory = currentDirectory || Harness.IO.getCurrentDirectory();
+            if (typeof currentDirectory === "undefined") {
+                currentDirectory = Harness.IO.getCurrentDirectory();
+            }
 
             // Parse settings
             if (harnessSettings) {
diff --git a/src/harness/harnessLanguageService.ts b/src/harness/harnessLanguageService.ts
index b3478e4060957..c9d31447df75b 100644
--- a/src/harness/harnessLanguageService.ts
+++ b/src/harness/harnessLanguageService.ts
@@ -246,16 +246,21 @@ namespace Harness.LanguageService {
                 };
                 this.getTypeReferenceDirectiveResolutionsForFile = (fileName) => {
                     const scriptInfo = this.getScriptInfo(fileName);
-                    const preprocessInfo = ts.preProcessFile(scriptInfo.content, /*readImportFiles*/ false);
-                    const resolutions: ts.Map<ts.ResolvedTypeReferenceDirective> = {};
-                    const settings = this.nativeHost.getCompilationSettings();
-                    for (const typeReferenceDirective of preprocessInfo.typeReferenceDirectives) {
-                        const resolutionInfo = ts.resolveTypeReferenceDirective(typeReferenceDirective.fileName, fileName, settings, moduleResolutionHost);
-                        if (resolutionInfo.resolvedTypeReferenceDirective.resolvedFileName) {
-                            resolutions[typeReferenceDirective.fileName] = resolutionInfo.resolvedTypeReferenceDirective;
+                    if (scriptInfo) {
+                        const preprocessInfo = ts.preProcessFile(scriptInfo.content, /*readImportFiles*/ false);
+                        const resolutions: ts.Map<ts.ResolvedTypeReferenceDirective> = {};
+                        const settings = this.nativeHost.getCompilationSettings();
+                        for (const typeReferenceDirective of preprocessInfo.typeReferenceDirectives) {
+                            const resolutionInfo = ts.resolveTypeReferenceDirective(typeReferenceDirective.fileName, fileName, settings, moduleResolutionHost);
+                            if (resolutionInfo.resolvedTypeReferenceDirective.resolvedFileName) {
+                                resolutions[typeReferenceDirective.fileName] = resolutionInfo.resolvedTypeReferenceDirective;
+                            }
                         }
+                        return JSON.stringify(resolutions);
+                    }
+                    else {
+                        return "[]";
                     }
-                    return JSON.stringify(resolutions);
                 };
             }
         }
diff --git a/src/harness/projectsRunner.ts b/src/harness/projectsRunner.ts
index 64d07b1d88a2a..6bf73ecced773 100644
--- a/src/harness/projectsRunner.ts
+++ b/src/harness/projectsRunner.ts
@@ -185,7 +185,8 @@ class ProjectRunner extends RunnerBase {
                     useCaseSensitiveFileNames: () => Harness.IO.useCaseSensitiveFileNames(),
                     getNewLine: () => Harness.IO.newLine(),
                     fileExists: fileName => fileName === Harness.Compiler.defaultLibFileName ||  getSourceFileText(fileName) !== undefined,
-                    readFile: fileName => Harness.IO.readFile(fileName)
+                    readFile: fileName => Harness.IO.readFile(fileName),
+                    getDirectories: path => Harness.IO.getDirectories(path)
                 };
             }
         }
diff --git a/src/server/editorServices.ts b/src/server/editorServices.ts
index 8eae43b503d3f..a53e9b3d5a012 100644
--- a/src/server/editorServices.ts
+++ b/src/server/editorServices.ts
@@ -315,6 +315,10 @@ namespace ts.server {
             return this.host.directoryExists(path);
         }
 
+        getDirectories(path: string): string[] {
+            return this.host.getDirectories ? this.host.getDirectories(path) : [];
+        }
+
         /**
          *  @param line 1 based index
          */
diff --git a/src/services/services.ts b/src/services/services.ts
index 34b521b34961a..10d9f9e48efd1 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -1058,6 +1058,7 @@ namespace ts {
         resolveModuleNames?(moduleNames: string[], containingFile: string): ResolvedModule[];
         resolveTypeReferenceDirectives?(typeDirectiveNames: string[], containingFile: string): ResolvedTypeReferenceDirective[];
         directoryExists?(directoryName: string): boolean;
+        getDirectories?(directoryName: string): string[];
     }
 
     //
@@ -1983,7 +1984,8 @@ namespace ts {
             getNewLine: () => newLine,
             fileExists: (fileName): boolean => fileName === inputFileName,
             readFile: (fileName): string => "",
-            directoryExists: directoryExists => true
+            directoryExists: directoryExists => true,
+            getDirectories: (path: string) => []
         };
 
         const program = createProgram([inputFileName], options, compilerHost);
@@ -2086,7 +2088,7 @@ namespace ts {
         const getCanonicalFileName = createGetCanonicalFileName(!!useCaseSensitiveFileNames);
 
         function getKeyForCompilationSettings(settings: CompilerOptions): DocumentRegistryBucketKey {
-            return <DocumentRegistryBucketKey>`_${settings.target}|${settings.module}|${settings.noResolve}|${settings.jsx}|${settings.allowJs}|${settings.baseUrl}|${settings.typesRoot}|${settings.typesSearchPaths}|${JSON.stringify(settings.rootDirs)}|${JSON.stringify(settings.paths)}`;
+            return <DocumentRegistryBucketKey>`_${settings.target}|${settings.module}|${settings.noResolve}|${settings.jsx}|${settings.allowJs}|${settings.baseUrl}|${settings.typeRoots}|${JSON.stringify(settings.rootDirs)}|${JSON.stringify(settings.paths)}`;
         }
 
         function getBucketForCompilationSettings(key: DocumentRegistryBucketKey, createIfMissing: boolean): FileMap<DocumentRegistryEntry> {
@@ -2945,8 +2947,10 @@ namespace ts {
                     return entry && entry.scriptSnapshot.getText(0, entry.scriptSnapshot.getLength());
                 },
                 directoryExists: directoryName => {
-                    Debug.assert(!host.resolveModuleNames || !host.resolveTypeReferenceDirectives);
                     return directoryProbablyExists(directoryName, host);
+                },
+                getDirectories: path => {
+                    return host.getDirectories ? host.getDirectories(path) : [];
                 }
             };
             if (host.trace) {
diff --git a/tests/baselines/reference/commonSourceDir5.js b/tests/baselines/reference/commonSourceDir5.js
index 7a43aba254e1d..1e404b26e137d 100644
--- a/tests/baselines/reference/commonSourceDir5.js
+++ b/tests/baselines/reference/commonSourceDir5.js
@@ -1,6 +1,7 @@
 //// [tests/cases/compiler/commonSourceDir5.ts] ////
 
 //// [bar.ts]
+
 import {z} from "./foo";
 export var x = z + z;
 
diff --git a/tests/baselines/reference/commonSourceDir5.symbols b/tests/baselines/reference/commonSourceDir5.symbols
index 6426ac39de3c4..67494af40fa53 100644
--- a/tests/baselines/reference/commonSourceDir5.symbols
+++ b/tests/baselines/reference/commonSourceDir5.symbols
@@ -1,11 +1,12 @@
 === A:/bar.ts ===
+
 import {z} from "./foo";
->z : Symbol(z, Decl(bar.ts, 0, 8))
+>z : Symbol(z, Decl(bar.ts, 1, 8))
 
 export var x = z + z;
->x : Symbol(x, Decl(bar.ts, 1, 10))
->z : Symbol(z, Decl(bar.ts, 0, 8))
->z : Symbol(z, Decl(bar.ts, 0, 8))
+>x : Symbol(x, Decl(bar.ts, 2, 10))
+>z : Symbol(z, Decl(bar.ts, 1, 8))
+>z : Symbol(z, Decl(bar.ts, 1, 8))
 
 === A:/foo.ts ===
 import {pi} from "B:/baz";
diff --git a/tests/baselines/reference/commonSourceDir5.types b/tests/baselines/reference/commonSourceDir5.types
index ff13bb20215c0..dd72099d54207 100644
--- a/tests/baselines/reference/commonSourceDir5.types
+++ b/tests/baselines/reference/commonSourceDir5.types
@@ -1,4 +1,5 @@
 === A:/bar.ts ===
+
 import {z} from "./foo";
 >z : number
 
diff --git a/tests/baselines/reference/library-reference-1.symbols b/tests/baselines/reference/library-reference-1.symbols
index 0e848c626c541..14a6b115009e4 100644
--- a/tests/baselines/reference/library-reference-1.symbols
+++ b/tests/baselines/reference/library-reference-1.symbols
@@ -1,11 +1,11 @@
-=== /consumer.ts ===
+=== /src/consumer.ts ===
 /// <reference types="jquery" />
 $.foo();
 >$.foo : Symbol(foo, Decl(index.d.ts, 3, 16))
 >$ : Symbol($, Decl(index.d.ts, 3, 11))
 >foo : Symbol(foo, Decl(index.d.ts, 3, 16))
 
-=== /types/jquery/index.d.ts ===
+=== /src/types/jquery/index.d.ts ===
 
 // We can find typings in the ./types folder
 
diff --git a/tests/baselines/reference/library-reference-1.trace.json b/tests/baselines/reference/library-reference-1.trace.json
index 1b8c237dff15a..715572362407e 100644
--- a/tests/baselines/reference/library-reference-1.trace.json
+++ b/tests/baselines/reference/library-reference-1.trace.json
@@ -1,7 +1,12 @@
 [
-    "======== Resolving type reference directive 'jquery', containing file '/consumer.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
-    "File '/types/jquery/package.json' does not exist.",
-    "File '/types/jquery/index.d.ts' exist - use it as a name resolution result.",
-    "======== Type reference directive 'jquery' was successfully resolved to '/types/jquery/index.d.ts', primary: true. ========"
+    "======== Resolving type reference directive 'jquery', containing file '/src/consumer.ts', root directory 'types'. ========",
+    "Resolving with primary search path 'types'",
+    "File 'types/jquery/package.json' does not exist.",
+    "File 'types/jquery/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'jquery' was successfully resolved to 'types/jquery/index.d.ts', primary: true. ========",
+    "======== Resolving type reference directive 'jquery', containing file '/src/__inferred type names__.ts', root directory 'types'. ========",
+    "Resolving with primary search path 'types'",
+    "File 'types/jquery/package.json' does not exist.",
+    "File 'types/jquery/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'jquery' was successfully resolved to 'types/jquery/index.d.ts', primary: true. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/library-reference-1.types b/tests/baselines/reference/library-reference-1.types
index 99133f2f8df9a..c247e94617e40 100644
--- a/tests/baselines/reference/library-reference-1.types
+++ b/tests/baselines/reference/library-reference-1.types
@@ -1,4 +1,4 @@
-=== /consumer.ts ===
+=== /src/consumer.ts ===
 /// <reference types="jquery" />
 $.foo();
 >$.foo() : void
@@ -6,7 +6,7 @@ $.foo();
 >$ : { foo(): void; }
 >foo : () => void
 
-=== /types/jquery/index.d.ts ===
+=== /src/types/jquery/index.d.ts ===
 
 // We can find typings in the ./types folder
 
diff --git a/tests/baselines/reference/library-reference-10.symbols b/tests/baselines/reference/library-reference-10.symbols
index 9d0f7e4781e35..50159b4bfc329 100644
--- a/tests/baselines/reference/library-reference-10.symbols
+++ b/tests/baselines/reference/library-reference-10.symbols
@@ -1,11 +1,11 @@
-=== /consumer.ts ===
+=== /foo/consumer.ts ===
 /// <reference types="jquery" />
 $.foo();
 >$.foo : Symbol(foo, Decl(jquery.d.ts, 0, 16))
 >$ : Symbol($, Decl(jquery.d.ts, 0, 11))
 >foo : Symbol(foo, Decl(jquery.d.ts, 0, 16))
 
-=== /types/jquery/jquery.d.ts ===
+=== /foo/types/jquery/jquery.d.ts ===
 declare var $: { foo(): void };
 >$ : Symbol($, Decl(jquery.d.ts, 0, 11))
 >foo : Symbol(foo, Decl(jquery.d.ts, 0, 16))
diff --git a/tests/baselines/reference/library-reference-10.trace.json b/tests/baselines/reference/library-reference-10.trace.json
index e6a1918a44653..f4df00fa52ded 100644
--- a/tests/baselines/reference/library-reference-10.trace.json
+++ b/tests/baselines/reference/library-reference-10.trace.json
@@ -1,8 +1,14 @@
 [
-    "======== Resolving type reference directive 'jquery', containing file '/consumer.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
-    "Found 'package.json' at '/types/jquery/package.json'.",
-    "'package.json' has 'typings' field 'jquery.d.ts' that references '/types/jquery/jquery.d.ts'.",
-    "File '/types/jquery/jquery.d.ts' exist - use it as a name resolution result.",
-    "======== Type reference directive 'jquery' was successfully resolved to '/types/jquery/jquery.d.ts', primary: true. ========"
+    "======== Resolving type reference directive 'jquery', containing file '/foo/consumer.ts', root directory './types'. ========",
+    "Resolving with primary search path './types'",
+    "Found 'package.json' at './types/jquery/package.json'.",
+    "'package.json' has 'typings' field 'jquery.d.ts' that references 'types/jquery/jquery.d.ts'.",
+    "File 'types/jquery/jquery.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'jquery' was successfully resolved to 'types/jquery/jquery.d.ts', primary: true. ========",
+    "======== Resolving type reference directive 'jquery', containing file '/foo/__inferred type names__.ts', root directory './types'. ========",
+    "Resolving with primary search path './types'",
+    "Found 'package.json' at './types/jquery/package.json'.",
+    "'package.json' has 'typings' field 'jquery.d.ts' that references 'types/jquery/jquery.d.ts'.",
+    "File 'types/jquery/jquery.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'jquery' was successfully resolved to 'types/jquery/jquery.d.ts', primary: true. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/library-reference-10.types b/tests/baselines/reference/library-reference-10.types
index 42d78f72865c3..ca588d0bc030e 100644
--- a/tests/baselines/reference/library-reference-10.types
+++ b/tests/baselines/reference/library-reference-10.types
@@ -1,4 +1,4 @@
-=== /consumer.ts ===
+=== /foo/consumer.ts ===
 /// <reference types="jquery" />
 $.foo();
 >$.foo() : void
@@ -6,7 +6,7 @@ $.foo();
 >$ : { foo(): void; }
 >foo : () => void
 
-=== /types/jquery/jquery.d.ts ===
+=== /foo/types/jquery/jquery.d.ts ===
 declare var $: { foo(): void };
 >$ : { foo(): void; }
 >foo : () => void
diff --git a/tests/baselines/reference/library-reference-11.trace.json b/tests/baselines/reference/library-reference-11.trace.json
index 62d828d57d64f..7f6a32a0b238f 100644
--- a/tests/baselines/reference/library-reference-11.trace.json
+++ b/tests/baselines/reference/library-reference-11.trace.json
@@ -1,14 +1,8 @@
 [
-    "======== Resolving type reference directive 'jquery', containing file '/a/b/consumer.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
-    "File '/types/jquery/package.json' does not exist.",
-    "File '/types/jquery/index.d.ts' does not exist.",
-    "Resolving with primary search path '/node_modules/'",
-    "File '/node_modules/jquery/package.json' does not exist.",
-    "File '/node_modules/jquery/index.d.ts' does not exist.",
-    "Resolving with primary search path '/node_modules/@types/'",
-    "File '/node_modules/@types/jquery/package.json' does not exist.",
-    "File '/node_modules/@types/jquery/index.d.ts' does not exist.",
+    "======== Resolving type reference directive 'jquery', containing file '/a/b/consumer.ts', root directory 'node_modules/@types'. ========",
+    "Resolving with primary search path 'node_modules/@types'",
+    "File 'node_modules/@types/jquery/package.json' does not exist.",
+    "File 'node_modules/@types/jquery/index.d.ts' does not exist.",
     "Looking up in 'node_modules' folder, initial location '/a/b'",
     "File '/a/b/node_modules/jquery.ts' does not exist.",
     "File '/a/b/node_modules/jquery.d.ts' does not exist.",
diff --git a/tests/baselines/reference/library-reference-12.trace.json b/tests/baselines/reference/library-reference-12.trace.json
index abe1f6c0f4680..b3debaec9d6dd 100644
--- a/tests/baselines/reference/library-reference-12.trace.json
+++ b/tests/baselines/reference/library-reference-12.trace.json
@@ -1,14 +1,8 @@
 [
-    "======== Resolving type reference directive 'jquery', containing file '/a/b/consumer.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
-    "File '/types/jquery/package.json' does not exist.",
-    "File '/types/jquery/index.d.ts' does not exist.",
-    "Resolving with primary search path '/node_modules/'",
-    "File '/node_modules/jquery/package.json' does not exist.",
-    "File '/node_modules/jquery/index.d.ts' does not exist.",
-    "Resolving with primary search path '/node_modules/@types/'",
-    "File '/node_modules/@types/jquery/package.json' does not exist.",
-    "File '/node_modules/@types/jquery/index.d.ts' does not exist.",
+    "======== Resolving type reference directive 'jquery', containing file '/a/b/consumer.ts', root directory 'node_modules/@types'. ========",
+    "Resolving with primary search path 'node_modules/@types'",
+    "File 'node_modules/@types/jquery/package.json' does not exist.",
+    "File 'node_modules/@types/jquery/index.d.ts' does not exist.",
     "Looking up in 'node_modules' folder, initial location '/a/b'",
     "File '/a/b/node_modules/jquery.ts' does not exist.",
     "File '/a/b/node_modules/jquery.d.ts' does not exist.",
diff --git a/tests/baselines/reference/library-reference-13.trace.json b/tests/baselines/reference/library-reference-13.trace.json
index 2133414f41424..d8dfb57c2a66f 100644
--- a/tests/baselines/reference/library-reference-13.trace.json
+++ b/tests/baselines/reference/library-reference-13.trace.json
@@ -1,6 +1,6 @@
 [
-    "======== Resolving type reference directive 'jquery', containing file not set, root directory '/a'. ========",
-    "Resolving with primary search path '/a/types/'",
+    "======== Resolving type reference directive 'jquery', containing file '/a/b/__inferred type names__.ts', root directory '/a/types'. ========",
+    "Resolving with primary search path '/a/types'",
     "File '/a/types/jquery/package.json' does not exist.",
     "File '/a/types/jquery/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'jquery' was successfully resolved to '/a/types/jquery/index.d.ts', primary: true. ========"
diff --git a/tests/baselines/reference/library-reference-14.trace.json b/tests/baselines/reference/library-reference-14.trace.json
index 2133414f41424..d8dfb57c2a66f 100644
--- a/tests/baselines/reference/library-reference-14.trace.json
+++ b/tests/baselines/reference/library-reference-14.trace.json
@@ -1,6 +1,6 @@
 [
-    "======== Resolving type reference directive 'jquery', containing file not set, root directory '/a'. ========",
-    "Resolving with primary search path '/a/types/'",
+    "======== Resolving type reference directive 'jquery', containing file '/a/b/__inferred type names__.ts', root directory '/a/types'. ========",
+    "Resolving with primary search path '/a/types'",
     "File '/a/types/jquery/package.json' does not exist.",
     "File '/a/types/jquery/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'jquery' was successfully resolved to '/a/types/jquery/index.d.ts', primary: true. ========"
diff --git a/tests/baselines/reference/library-reference-15.errors.txt b/tests/baselines/reference/library-reference-15.errors.txt
index a311633ca76d5..9586ba8bc724a 100644
--- a/tests/baselines/reference/library-reference-15.errors.txt
+++ b/tests/baselines/reference/library-reference-15.errors.txt
@@ -1,15 +1,15 @@
-error TS2304: Cannot find name 'jquery'.
-/a/b/consumer.ts(1,1): error TS2304: Cannot find name '$'.
+/a/b/consumer.ts(2,1): error TS2304: Cannot find name '$2'.
 
 
-!!! error TS2304: Cannot find name 'jquery'.
 ==== /a/b/consumer.ts (1 errors) ====
-    $.foo();
-    ~
-!!! error TS2304: Cannot find name '$'.
-    
+    $.foo(); // should OK
+    $2.foo(); // should error
+    ~~
+!!! error TS2304: Cannot find name '$2'.
 ==== /a/types/jquery/index.d.ts (0 errors) ====
     
     declare var $: { foo(): void };
     
+==== /a/types/jquery2/index.d.ts (0 errors) ====
+    declare var $2: { foo(): void };
     
\ No newline at end of file
diff --git a/tests/baselines/reference/library-reference-15.js b/tests/baselines/reference/library-reference-15.js
index f9aa7038d539d..c1caa0c45e75a 100644
--- a/tests/baselines/reference/library-reference-15.js
+++ b/tests/baselines/reference/library-reference-15.js
@@ -3,11 +3,14 @@
 //// [index.d.ts]
 
 declare var $: { foo(): void };
-
 
-//// [consumer.ts]
-$.foo();
+//// [index.d.ts]
+declare var $2: { foo(): void };
 
+//// [consumer.ts]
+$.foo(); // should OK
+$2.foo(); // should error
 
 //// [consumer.js]
-$.foo();
+$.foo(); // should OK
+$2.foo(); // should error
diff --git a/tests/baselines/reference/library-reference-15.trace.json b/tests/baselines/reference/library-reference-15.trace.json
index b8029a0b61fc3..3e9d7dba1d21d 100644
--- a/tests/baselines/reference/library-reference-15.trace.json
+++ b/tests/baselines/reference/library-reference-15.trace.json
@@ -1,24 +1,7 @@
 [
-    "======== Resolving type reference directive 'jquery', containing file not set, root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
-    "File '/types/jquery/package.json' does not exist.",
-    "File '/types/jquery/index.d.ts' does not exist.",
-    "Resolving with primary search path '/node_modules/'",
-    "File '/node_modules/jquery/package.json' does not exist.",
-    "File '/node_modules/jquery/index.d.ts' does not exist.",
-    "Resolving with primary search path '/node_modules/@types/'",
-    "File '/node_modules/@types/jquery/package.json' does not exist.",
-    "File '/node_modules/@types/jquery/index.d.ts' does not exist.",
-    "Looking up in 'node_modules' folder, initial location '/'",
-    "File '/node_modules/jquery.ts' does not exist.",
-    "File '/node_modules/jquery.d.ts' does not exist.",
-    "File '/node_modules/jquery/package.json' does not exist.",
-    "File '/node_modules/jquery/index.ts' does not exist.",
-    "File '/node_modules/jquery/index.d.ts' does not exist.",
-    "File '/node_modules/@types/jquery.ts' does not exist.",
-    "File '/node_modules/@types/jquery.d.ts' does not exist.",
-    "File '/node_modules/@types/jquery/package.json' does not exist.",
-    "File '/node_modules/@types/jquery/index.ts' does not exist.",
-    "File '/node_modules/@types/jquery/index.d.ts' does not exist.",
-    "======== Type reference directive 'jquery' was not resolved. ========"
+    "======== Resolving type reference directive 'jquery', containing file '/a/b/__inferred type names__.ts', root directory 'types'. ========",
+    "Resolving with primary search path 'types'",
+    "File 'types/jquery/package.json' does not exist.",
+    "File 'types/jquery/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'jquery' was successfully resolved to 'types/jquery/index.d.ts', primary: true. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/library-reference-2.trace.json b/tests/baselines/reference/library-reference-2.trace.json
index b5ef5f3e2089a..c26f7d2763d7f 100644
--- a/tests/baselines/reference/library-reference-2.trace.json
+++ b/tests/baselines/reference/library-reference-2.trace.json
@@ -1,6 +1,12 @@
 [
-    "======== Resolving type reference directive 'jquery', containing file '/consumer.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
+    "======== Resolving type reference directive 'jquery', containing file '/consumer.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
+    "Found 'package.json' at '/types/jquery/package.json'.",
+    "'package.json' has 'types' field 'jquery.d.ts' that references '/types/jquery/jquery.d.ts'.",
+    "File '/types/jquery/jquery.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'jquery' was successfully resolved to '/types/jquery/jquery.d.ts', primary: true. ========",
+    "======== Resolving type reference directive 'jquery', containing file '/__inferred type names__.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
     "Found 'package.json' at '/types/jquery/package.json'.",
     "'package.json' has 'types' field 'jquery.d.ts' that references '/types/jquery/jquery.d.ts'.",
     "File '/types/jquery/jquery.d.ts' exist - use it as a name resolution result.",
diff --git a/tests/baselines/reference/library-reference-3.trace.json b/tests/baselines/reference/library-reference-3.trace.json
index 30dbbc3fca4d2..909e42140c850 100644
--- a/tests/baselines/reference/library-reference-3.trace.json
+++ b/tests/baselines/reference/library-reference-3.trace.json
@@ -1,10 +1,13 @@
 [
-    "======== Resolving type reference directive 'jquery', containing file '/src/consumer.ts', root directory '/src'. ========",
-    "Resolving with primary search path '/src/types/'",
-    "File '/src/types/jquery/package.json' does not exist.",
-    "File '/src/types/jquery/index.d.ts' does not exist.",
-    "Resolving with primary search path '/src/node_modules/'",
+    "======== Resolving type reference directive 'jquery', containing file '/src/consumer.ts', root directory 'node_modules/@types'. ========",
+    "Resolving with primary search path 'node_modules/@types'",
+    "File 'node_modules/@types/jquery/package.json' does not exist.",
+    "File 'node_modules/@types/jquery/index.d.ts' does not exist.",
+    "Looking up in 'node_modules' folder, initial location '/src'",
+    "File '/src/node_modules/jquery.ts' does not exist.",
+    "File '/src/node_modules/jquery.d.ts' does not exist.",
     "File '/src/node_modules/jquery/package.json' does not exist.",
+    "File '/src/node_modules/jquery/index.ts' does not exist.",
     "File '/src/node_modules/jquery/index.d.ts' exist - use it as a name resolution result.",
-    "======== Type reference directive 'jquery' was successfully resolved to '/src/node_modules/jquery/index.d.ts', primary: true. ========"
+    "======== Type reference directive 'jquery' was successfully resolved to '/src/node_modules/jquery/index.d.ts', primary: false. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/library-reference-4.trace.json b/tests/baselines/reference/library-reference-4.trace.json
index 90b6eb7b01d74..5df7320d3223c 100644
--- a/tests/baselines/reference/library-reference-4.trace.json
+++ b/tests/baselines/reference/library-reference-4.trace.json
@@ -1,14 +1,8 @@
 [
     "======== Resolving type reference directive 'foo', containing file '/src/root.ts', root directory '/src'. ========",
-    "Resolving with primary search path '/src/types/'",
-    "File '/src/types/foo/package.json' does not exist.",
-    "File '/src/types/foo/index.d.ts' does not exist.",
-    "Resolving with primary search path '/src/node_modules/'",
-    "File '/src/node_modules/foo/package.json' does not exist.",
-    "File '/src/node_modules/foo/index.d.ts' does not exist.",
-    "Resolving with primary search path '/src/node_modules/@types/'",
-    "File '/src/node_modules/@types/foo/package.json' does not exist.",
-    "File '/src/node_modules/@types/foo/index.d.ts' does not exist.",
+    "Resolving with primary search path '/src'",
+    "File '/src/foo/package.json' does not exist.",
+    "File '/src/foo/index.d.ts' does not exist.",
     "Looking up in 'node_modules' folder, initial location '/src'",
     "File '/src/node_modules/foo.ts' does not exist.",
     "File '/src/node_modules/foo.d.ts' does not exist.",
@@ -27,15 +21,9 @@
     "File '/node_modules/foo/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'foo' was successfully resolved to '/node_modules/foo/index.d.ts', primary: false. ========",
     "======== Resolving type reference directive 'bar', containing file '/src/root.ts', root directory '/src'. ========",
-    "Resolving with primary search path '/src/types/'",
-    "File '/src/types/bar/package.json' does not exist.",
-    "File '/src/types/bar/index.d.ts' does not exist.",
-    "Resolving with primary search path '/src/node_modules/'",
-    "File '/src/node_modules/bar/package.json' does not exist.",
-    "File '/src/node_modules/bar/index.d.ts' does not exist.",
-    "Resolving with primary search path '/src/node_modules/@types/'",
-    "File '/src/node_modules/@types/bar/package.json' does not exist.",
-    "File '/src/node_modules/@types/bar/index.d.ts' does not exist.",
+    "Resolving with primary search path '/src'",
+    "File '/src/bar/package.json' does not exist.",
+    "File '/src/bar/index.d.ts' does not exist.",
     "Looking up in 'node_modules' folder, initial location '/src'",
     "File '/src/node_modules/bar.ts' does not exist.",
     "File '/src/node_modules/bar.d.ts' does not exist.",
@@ -54,15 +42,9 @@
     "File '/node_modules/bar/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'bar' was successfully resolved to '/node_modules/bar/index.d.ts', primary: false. ========",
     "======== Resolving type reference directive 'alpha', containing file '/node_modules/foo/index.d.ts', root directory '/src'. ========",
-    "Resolving with primary search path '/src/types/'",
-    "File '/src/types/alpha/package.json' does not exist.",
-    "File '/src/types/alpha/index.d.ts' does not exist.",
-    "Resolving with primary search path '/src/node_modules/'",
-    "File '/src/node_modules/alpha/package.json' does not exist.",
-    "File '/src/node_modules/alpha/index.d.ts' does not exist.",
-    "Resolving with primary search path '/src/node_modules/@types/'",
-    "File '/src/node_modules/@types/alpha/package.json' does not exist.",
-    "File '/src/node_modules/@types/alpha/index.d.ts' does not exist.",
+    "Resolving with primary search path '/src'",
+    "File '/src/alpha/package.json' does not exist.",
+    "File '/src/alpha/index.d.ts' does not exist.",
     "Looking up in 'node_modules' folder, initial location '/node_modules/foo'",
     "File '/node_modules/foo/node_modules/alpha.ts' does not exist.",
     "File '/node_modules/foo/node_modules/alpha.d.ts' does not exist.",
@@ -71,15 +53,9 @@
     "File '/node_modules/foo/node_modules/alpha/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'alpha' was successfully resolved to '/node_modules/foo/node_modules/alpha/index.d.ts', primary: false. ========",
     "======== Resolving type reference directive 'alpha', containing file '/node_modules/bar/index.d.ts', root directory '/src'. ========",
-    "Resolving with primary search path '/src/types/'",
-    "File '/src/types/alpha/package.json' does not exist.",
-    "File '/src/types/alpha/index.d.ts' does not exist.",
-    "Resolving with primary search path '/src/node_modules/'",
-    "File '/src/node_modules/alpha/package.json' does not exist.",
-    "File '/src/node_modules/alpha/index.d.ts' does not exist.",
-    "Resolving with primary search path '/src/node_modules/@types/'",
-    "File '/src/node_modules/@types/alpha/package.json' does not exist.",
-    "File '/src/node_modules/@types/alpha/index.d.ts' does not exist.",
+    "Resolving with primary search path '/src'",
+    "File '/src/alpha/package.json' does not exist.",
+    "File '/src/alpha/index.d.ts' does not exist.",
     "Looking up in 'node_modules' folder, initial location '/node_modules/bar'",
     "File '/node_modules/bar/node_modules/alpha.ts' does not exist.",
     "File '/node_modules/bar/node_modules/alpha.d.ts' does not exist.",
diff --git a/tests/baselines/reference/library-reference-5.trace.json b/tests/baselines/reference/library-reference-5.trace.json
index ad34e9e3159f3..9b8705f032311 100644
--- a/tests/baselines/reference/library-reference-5.trace.json
+++ b/tests/baselines/reference/library-reference-5.trace.json
@@ -1,30 +1,50 @@
 [
-    "======== Resolving type reference directive 'foo', containing file '/src/root.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
-    "File '/types/foo/package.json' does not exist.",
-    "File '/types/foo/index.d.ts' does not exist.",
-    "Resolving with primary search path '/node_modules/'",
+    "======== Resolving type reference directive 'foo', containing file '/src/root.ts', root directory 'types'. ========",
+    "Resolving with primary search path 'types'",
+    "File 'types/foo/package.json' does not exist.",
+    "File 'types/foo/index.d.ts' does not exist.",
+    "Looking up in 'node_modules' folder, initial location '/src'",
+    "File '/src/node_modules/foo.ts' does not exist.",
+    "File '/src/node_modules/foo.d.ts' does not exist.",
+    "File '/src/node_modules/foo/package.json' does not exist.",
+    "File '/src/node_modules/foo/index.ts' does not exist.",
+    "File '/src/node_modules/foo/index.d.ts' does not exist.",
+    "File '/src/node_modules/@types/foo.ts' does not exist.",
+    "File '/src/node_modules/@types/foo.d.ts' does not exist.",
+    "File '/src/node_modules/@types/foo/package.json' does not exist.",
+    "File '/src/node_modules/@types/foo/index.ts' does not exist.",
+    "File '/src/node_modules/@types/foo/index.d.ts' does not exist.",
+    "File '/node_modules/foo.ts' does not exist.",
+    "File '/node_modules/foo.d.ts' does not exist.",
     "File '/node_modules/foo/package.json' does not exist.",
+    "File '/node_modules/foo/index.ts' does not exist.",
     "File '/node_modules/foo/index.d.ts' exist - use it as a name resolution result.",
-    "======== Type reference directive 'foo' was successfully resolved to '/node_modules/foo/index.d.ts', primary: true. ========",
-    "======== Resolving type reference directive 'bar', containing file '/src/root.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
-    "File '/types/bar/package.json' does not exist.",
-    "File '/types/bar/index.d.ts' does not exist.",
-    "Resolving with primary search path '/node_modules/'",
+    "======== Type reference directive 'foo' was successfully resolved to '/node_modules/foo/index.d.ts', primary: false. ========",
+    "======== Resolving type reference directive 'bar', containing file '/src/root.ts', root directory 'types'. ========",
+    "Resolving with primary search path 'types'",
+    "File 'types/bar/package.json' does not exist.",
+    "File 'types/bar/index.d.ts' does not exist.",
+    "Looking up in 'node_modules' folder, initial location '/src'",
+    "File '/src/node_modules/bar.ts' does not exist.",
+    "File '/src/node_modules/bar.d.ts' does not exist.",
+    "File '/src/node_modules/bar/package.json' does not exist.",
+    "File '/src/node_modules/bar/index.ts' does not exist.",
+    "File '/src/node_modules/bar/index.d.ts' does not exist.",
+    "File '/src/node_modules/@types/bar.ts' does not exist.",
+    "File '/src/node_modules/@types/bar.d.ts' does not exist.",
+    "File '/src/node_modules/@types/bar/package.json' does not exist.",
+    "File '/src/node_modules/@types/bar/index.ts' does not exist.",
+    "File '/src/node_modules/@types/bar/index.d.ts' does not exist.",
+    "File '/node_modules/bar.ts' does not exist.",
+    "File '/node_modules/bar.d.ts' does not exist.",
     "File '/node_modules/bar/package.json' does not exist.",
+    "File '/node_modules/bar/index.ts' does not exist.",
     "File '/node_modules/bar/index.d.ts' exist - use it as a name resolution result.",
-    "======== Type reference directive 'bar' was successfully resolved to '/node_modules/bar/index.d.ts', primary: true. ========",
-    "======== Resolving type reference directive 'alpha', containing file '/node_modules/foo/index.d.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
-    "File '/types/alpha/package.json' does not exist.",
-    "File '/types/alpha/index.d.ts' does not exist.",
-    "Resolving with primary search path '/node_modules/'",
-    "File '/node_modules/alpha/package.json' does not exist.",
-    "File '/node_modules/alpha/index.d.ts' does not exist.",
-    "Resolving with primary search path '/node_modules/@types/'",
-    "File '/node_modules/@types/alpha/package.json' does not exist.",
-    "File '/node_modules/@types/alpha/index.d.ts' does not exist.",
+    "======== Type reference directive 'bar' was successfully resolved to '/node_modules/bar/index.d.ts', primary: false. ========",
+    "======== Resolving type reference directive 'alpha', containing file '/node_modules/foo/index.d.ts', root directory 'types'. ========",
+    "Resolving with primary search path 'types'",
+    "File 'types/alpha/package.json' does not exist.",
+    "File 'types/alpha/index.d.ts' does not exist.",
     "Looking up in 'node_modules' folder, initial location '/node_modules/foo'",
     "File '/node_modules/foo/node_modules/alpha.ts' does not exist.",
     "File '/node_modules/foo/node_modules/alpha.d.ts' does not exist.",
@@ -32,16 +52,10 @@
     "File '/node_modules/foo/node_modules/alpha/index.ts' does not exist.",
     "File '/node_modules/foo/node_modules/alpha/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'alpha' was successfully resolved to '/node_modules/foo/node_modules/alpha/index.d.ts', primary: false. ========",
-    "======== Resolving type reference directive 'alpha', containing file '/node_modules/bar/index.d.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
-    "File '/types/alpha/package.json' does not exist.",
-    "File '/types/alpha/index.d.ts' does not exist.",
-    "Resolving with primary search path '/node_modules/'",
-    "File '/node_modules/alpha/package.json' does not exist.",
-    "File '/node_modules/alpha/index.d.ts' does not exist.",
-    "Resolving with primary search path '/node_modules/@types/'",
-    "File '/node_modules/@types/alpha/package.json' does not exist.",
-    "File '/node_modules/@types/alpha/index.d.ts' does not exist.",
+    "======== Resolving type reference directive 'alpha', containing file '/node_modules/bar/index.d.ts', root directory 'types'. ========",
+    "Resolving with primary search path 'types'",
+    "File 'types/alpha/package.json' does not exist.",
+    "File 'types/alpha/index.d.ts' does not exist.",
     "Looking up in 'node_modules' folder, initial location '/node_modules/bar'",
     "File '/node_modules/bar/node_modules/alpha.ts' does not exist.",
     "File '/node_modules/bar/node_modules/alpha.d.ts' does not exist.",
diff --git a/tests/baselines/reference/library-reference-6.symbols b/tests/baselines/reference/library-reference-6.symbols
deleted file mode 100644
index 328842f804c56..0000000000000
--- a/tests/baselines/reference/library-reference-6.symbols
+++ /dev/null
@@ -1,16 +0,0 @@
-=== /src/foo.ts ===
-/// <reference types="alpha" />
-var x: string = alpha.a;
->x : Symbol(x, Decl(foo.ts, 1, 3))
->alpha.a : Symbol(a, Decl(index.d.ts, 3, 20))
->alpha : Symbol(alpha, Decl(index.d.ts, 3, 11))
->a : Symbol(a, Decl(index.d.ts, 3, 20))
-
-=== /types/alpha/index.d.ts ===
-
-// The primary lookup folder is relative to tsconfig.json, if present
-
-declare var alpha: { a: string };
->alpha : Symbol(alpha, Decl(index.d.ts, 3, 11))
->a : Symbol(a, Decl(index.d.ts, 3, 20))
-
diff --git a/tests/baselines/reference/library-reference-6.trace.json b/tests/baselines/reference/library-reference-6.trace.json
index 426214fdcfc7f..fc29f3f2478b8 100644
--- a/tests/baselines/reference/library-reference-6.trace.json
+++ b/tests/baselines/reference/library-reference-6.trace.json
@@ -1,7 +1,28 @@
 [
-    "======== Resolving type reference directive 'alpha', containing file '/src/foo.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
-    "File '/types/alpha/package.json' does not exist.",
-    "File '/types/alpha/index.d.ts' exist - use it as a name resolution result.",
-    "======== Type reference directive 'alpha' was successfully resolved to '/types/alpha/index.d.ts', primary: true. ========"
+    "======== Resolving type reference directive 'alpha', containing file '/src/foo.ts', root directory 'node_modules/@types'. ========",
+    "Resolving with primary search path 'node_modules/@types'",
+    "File 'node_modules/@types/alpha/package.json' does not exist.",
+    "File 'node_modules/@types/alpha/index.d.ts' does not exist.",
+    "Looking up in 'node_modules' folder, initial location '/src'",
+    "File '/src/node_modules/alpha.ts' does not exist.",
+    "File '/src/node_modules/alpha.d.ts' does not exist.",
+    "File '/src/node_modules/alpha/package.json' does not exist.",
+    "File '/src/node_modules/alpha/index.ts' does not exist.",
+    "File '/src/node_modules/alpha/index.d.ts' does not exist.",
+    "File '/src/node_modules/@types/alpha.ts' does not exist.",
+    "File '/src/node_modules/@types/alpha.d.ts' does not exist.",
+    "File '/src/node_modules/@types/alpha/package.json' does not exist.",
+    "File '/src/node_modules/@types/alpha/index.ts' does not exist.",
+    "File '/src/node_modules/@types/alpha/index.d.ts' does not exist.",
+    "File '/node_modules/alpha.ts' does not exist.",
+    "File '/node_modules/alpha.d.ts' does not exist.",
+    "File '/node_modules/alpha/package.json' does not exist.",
+    "File '/node_modules/alpha/index.ts' does not exist.",
+    "File '/node_modules/alpha/index.d.ts' does not exist.",
+    "File '/node_modules/@types/alpha.ts' does not exist.",
+    "File '/node_modules/@types/alpha.d.ts' does not exist.",
+    "File '/node_modules/@types/alpha/package.json' does not exist.",
+    "File '/node_modules/@types/alpha/index.ts' does not exist.",
+    "File '/node_modules/@types/alpha/index.d.ts' does not exist.",
+    "======== Type reference directive 'alpha' was not resolved. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/library-reference-6.types b/tests/baselines/reference/library-reference-6.types
deleted file mode 100644
index 2f6c1e49b891f..0000000000000
--- a/tests/baselines/reference/library-reference-6.types
+++ /dev/null
@@ -1,16 +0,0 @@
-=== /src/foo.ts ===
-/// <reference types="alpha" />
-var x: string = alpha.a;
->x : string
->alpha.a : string
->alpha : { a: string; }
->a : string
-
-=== /types/alpha/index.d.ts ===
-
-// The primary lookup folder is relative to tsconfig.json, if present
-
-declare var alpha: { a: string };
->alpha : { a: string; }
->a : string
-
diff --git a/tests/baselines/reference/library-reference-7.trace.json b/tests/baselines/reference/library-reference-7.trace.json
index 9c6b19390d062..909e42140c850 100644
--- a/tests/baselines/reference/library-reference-7.trace.json
+++ b/tests/baselines/reference/library-reference-7.trace.json
@@ -1,14 +1,8 @@
 [
-    "======== Resolving type reference directive 'jquery', containing file '/src/consumer.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
-    "File '/types/jquery/package.json' does not exist.",
-    "File '/types/jquery/index.d.ts' does not exist.",
-    "Resolving with primary search path '/node_modules/'",
-    "File '/node_modules/jquery/package.json' does not exist.",
-    "File '/node_modules/jquery/index.d.ts' does not exist.",
-    "Resolving with primary search path '/node_modules/@types/'",
-    "File '/node_modules/@types/jquery/package.json' does not exist.",
-    "File '/node_modules/@types/jquery/index.d.ts' does not exist.",
+    "======== Resolving type reference directive 'jquery', containing file '/src/consumer.ts', root directory 'node_modules/@types'. ========",
+    "Resolving with primary search path 'node_modules/@types'",
+    "File 'node_modules/@types/jquery/package.json' does not exist.",
+    "File 'node_modules/@types/jquery/index.d.ts' does not exist.",
     "Looking up in 'node_modules' folder, initial location '/src'",
     "File '/src/node_modules/jquery.ts' does not exist.",
     "File '/src/node_modules/jquery.d.ts' does not exist.",
diff --git a/tests/baselines/reference/library-reference-8.symbols b/tests/baselines/reference/library-reference-8.symbols
index 299a60f1b1dcb..a6a24689f3fcd 100644
--- a/tests/baselines/reference/library-reference-8.symbols
+++ b/tests/baselines/reference/library-reference-8.symbols
@@ -1,4 +1,4 @@
-=== /foo.ts ===
+=== /test/foo.ts ===
 /// <reference types="alpha" />
 /// <reference types="beta" />
 var x: string = alpha.a + beta.b;
@@ -11,7 +11,7 @@ var x: string = alpha.a + beta.b;
 >b : Symbol(b, Decl(index.d.ts, 1, 19))
 
 
-=== /types/alpha/index.d.ts ===
+=== /test/types/alpha/index.d.ts ===
 
 // Don't crash in circular library reference situations
 
@@ -20,7 +20,7 @@ declare var alpha: { a: string };
 >alpha : Symbol(alpha, Decl(index.d.ts, 4, 11))
 >a : Symbol(a, Decl(index.d.ts, 4, 20))
 
-=== /types/beta/index.d.ts ===
+=== /test/types/beta/index.d.ts ===
 /// <reference types="alpha" />
 declare var beta: { b: string };
 >beta : Symbol(beta, Decl(index.d.ts, 1, 11))
diff --git a/tests/baselines/reference/library-reference-8.trace.json b/tests/baselines/reference/library-reference-8.trace.json
index b1dc64786880d..d34f206e5816b 100644
--- a/tests/baselines/reference/library-reference-8.trace.json
+++ b/tests/baselines/reference/library-reference-8.trace.json
@@ -1,22 +1,32 @@
 [
-    "======== Resolving type reference directive 'alpha', containing file '/foo.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
-    "File '/types/alpha/package.json' does not exist.",
-    "File '/types/alpha/index.d.ts' exist - use it as a name resolution result.",
-    "======== Type reference directive 'alpha' was successfully resolved to '/types/alpha/index.d.ts', primary: true. ========",
-    "======== Resolving type reference directive 'beta', containing file '/foo.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
-    "File '/types/beta/package.json' does not exist.",
-    "File '/types/beta/index.d.ts' exist - use it as a name resolution result.",
-    "======== Type reference directive 'beta' was successfully resolved to '/types/beta/index.d.ts', primary: true. ========",
-    "======== Resolving type reference directive 'beta', containing file '/types/alpha/index.d.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
-    "File '/types/beta/package.json' does not exist.",
-    "File '/types/beta/index.d.ts' exist - use it as a name resolution result.",
-    "======== Type reference directive 'beta' was successfully resolved to '/types/beta/index.d.ts', primary: true. ========",
-    "======== Resolving type reference directive 'alpha', containing file '/types/beta/index.d.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
-    "File '/types/alpha/package.json' does not exist.",
-    "File '/types/alpha/index.d.ts' exist - use it as a name resolution result.",
-    "======== Type reference directive 'alpha' was successfully resolved to '/types/alpha/index.d.ts', primary: true. ========"
+    "======== Resolving type reference directive 'alpha', containing file '/test/foo.ts', root directory '/test/types'. ========",
+    "Resolving with primary search path '/test/types'",
+    "File '/test/types/alpha/package.json' does not exist.",
+    "File '/test/types/alpha/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'alpha' was successfully resolved to '/test/types/alpha/index.d.ts', primary: true. ========",
+    "======== Resolving type reference directive 'beta', containing file '/test/foo.ts', root directory '/test/types'. ========",
+    "Resolving with primary search path '/test/types'",
+    "File '/test/types/beta/package.json' does not exist.",
+    "File '/test/types/beta/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'beta' was successfully resolved to '/test/types/beta/index.d.ts', primary: true. ========",
+    "======== Resolving type reference directive 'beta', containing file '/test/types/alpha/index.d.ts', root directory '/test/types'. ========",
+    "Resolving with primary search path '/test/types'",
+    "File '/test/types/beta/package.json' does not exist.",
+    "File '/test/types/beta/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'beta' was successfully resolved to '/test/types/beta/index.d.ts', primary: true. ========",
+    "======== Resolving type reference directive 'alpha', containing file '/test/types/beta/index.d.ts', root directory '/test/types'. ========",
+    "Resolving with primary search path '/test/types'",
+    "File '/test/types/alpha/package.json' does not exist.",
+    "File '/test/types/alpha/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'alpha' was successfully resolved to '/test/types/alpha/index.d.ts', primary: true. ========",
+    "======== Resolving type reference directive 'alpha', containing file '/test/__inferred type names__.ts', root directory '/test/types'. ========",
+    "Resolving with primary search path '/test/types'",
+    "File '/test/types/alpha/package.json' does not exist.",
+    "File '/test/types/alpha/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'alpha' was successfully resolved to '/test/types/alpha/index.d.ts', primary: true. ========",
+    "======== Resolving type reference directive 'beta', containing file '/test/__inferred type names__.ts', root directory '/test/types'. ========",
+    "Resolving with primary search path '/test/types'",
+    "File '/test/types/beta/package.json' does not exist.",
+    "File '/test/types/beta/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'beta' was successfully resolved to '/test/types/beta/index.d.ts', primary: true. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/library-reference-8.types b/tests/baselines/reference/library-reference-8.types
index b0780d90f63ac..d8a2b6e963870 100644
--- a/tests/baselines/reference/library-reference-8.types
+++ b/tests/baselines/reference/library-reference-8.types
@@ -1,4 +1,4 @@
-=== /foo.ts ===
+=== /test/foo.ts ===
 /// <reference types="alpha" />
 /// <reference types="beta" />
 var x: string = alpha.a + beta.b;
@@ -12,7 +12,7 @@ var x: string = alpha.a + beta.b;
 >b : string
 
 
-=== /types/alpha/index.d.ts ===
+=== /test/types/alpha/index.d.ts ===
 
 // Don't crash in circular library reference situations
 
@@ -21,7 +21,7 @@ declare var alpha: { a: string };
 >alpha : { a: string; }
 >a : string
 
-=== /types/beta/index.d.ts ===
+=== /test/types/beta/index.d.ts ===
 /// <reference types="alpha" />
 declare var beta: { b: string };
 >beta : { b: string; }
diff --git a/tests/baselines/reference/library-reference-9.js b/tests/baselines/reference/library-reference-9.js
deleted file mode 100644
index ccb3b3213a9f1..0000000000000
--- a/tests/baselines/reference/library-reference-9.js
+++ /dev/null
@@ -1,16 +0,0 @@
-//// [tests/cases/conformance/references/library-reference-9.ts] ////
-
-//// [index.d.ts]
-
-// Use types search path
-
-declare var alpha: { a: string };
-
-//// [foo.ts]
-/// <reference types="alpha" />
-var x: string = alpha.a;
-
-
-//// [foo.js]
-/// <reference types="alpha" />
-var x = alpha.a;
diff --git a/tests/baselines/reference/library-reference-9.symbols b/tests/baselines/reference/library-reference-9.symbols
deleted file mode 100644
index 62cde2117dff6..0000000000000
--- a/tests/baselines/reference/library-reference-9.symbols
+++ /dev/null
@@ -1,16 +0,0 @@
-=== /base/src/foo.ts ===
-/// <reference types="alpha" />
-var x: string = alpha.a;
->x : Symbol(x, Decl(foo.ts, 1, 3))
->alpha.a : Symbol(a, Decl(index.d.ts, 3, 20))
->alpha : Symbol(alpha, Decl(index.d.ts, 3, 11))
->a : Symbol(a, Decl(index.d.ts, 3, 20))
-
-=== /share/typelib/alpha/index.d.ts ===
-
-// Use types search path
-
-declare var alpha: { a: string };
->alpha : Symbol(alpha, Decl(index.d.ts, 3, 11))
->a : Symbol(a, Decl(index.d.ts, 3, 20))
-
diff --git a/tests/baselines/reference/library-reference-9.trace.json b/tests/baselines/reference/library-reference-9.trace.json
deleted file mode 100644
index e2fdfdc05500c..0000000000000
--- a/tests/baselines/reference/library-reference-9.trace.json
+++ /dev/null
@@ -1,7 +0,0 @@
-[
-    "======== Resolving type reference directive 'alpha', containing file '/base/src/foo.ts', root directory '/'. ========",
-    "Resolving with primary search path '/share/typelib'",
-    "File '/share/typelib/alpha/package.json' does not exist.",
-    "File '/share/typelib/alpha/index.d.ts' exist - use it as a name resolution result.",
-    "======== Type reference directive 'alpha' was successfully resolved to '/share/typelib/alpha/index.d.ts', primary: true. ========"
-]
\ No newline at end of file
diff --git a/tests/baselines/reference/library-reference-9.types b/tests/baselines/reference/library-reference-9.types
deleted file mode 100644
index 8df2179e24995..0000000000000
--- a/tests/baselines/reference/library-reference-9.types
+++ /dev/null
@@ -1,16 +0,0 @@
-=== /base/src/foo.ts ===
-/// <reference types="alpha" />
-var x: string = alpha.a;
->x : string
->alpha.a : string
->alpha : { a: string; }
->a : string
-
-=== /share/typelib/alpha/index.d.ts ===
-
-// Use types search path
-
-declare var alpha: { a: string };
->alpha : { a: string; }
->a : string
-
diff --git a/tests/baselines/reference/moduleResolutionWithSymlinks.errors.txt b/tests/baselines/reference/moduleResolutionWithSymlinks.errors.txt
new file mode 100644
index 0000000000000..b51933902a469
--- /dev/null
+++ b/tests/baselines/reference/moduleResolutionWithSymlinks.errors.txt
@@ -0,0 +1,21 @@
+/src/library-b/index.ts(1,23): error TS2307: Cannot find module 'library-a'.
+
+
+==== /src/app.ts (0 errors) ====
+    import { MyClass } from "./library-a";
+    import { MyClass2 } from "./library-b";
+    
+    let x: MyClass;
+    let y: MyClass2;
+    x = y;
+    y = x;
+==== /src/library-a/index.ts (0 errors) ====
+    
+    export class MyClass{}
+    
+==== /src/library-b/index.ts (1 errors) ====
+    import {MyClass} from "library-a";
+                          ~~~~~~~~~~~
+!!! error TS2307: Cannot find module 'library-a'.
+    export { MyClass as MyClass2 }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/moduleResolutionWithSymlinks.symbols b/tests/baselines/reference/moduleResolutionWithSymlinks.symbols
deleted file mode 100644
index ea73755deefe6..0000000000000
--- a/tests/baselines/reference/moduleResolutionWithSymlinks.symbols
+++ /dev/null
@@ -1,36 +0,0 @@
-=== /src/app.ts ===
-import { MyClass } from "./library-a";
->MyClass : Symbol(MyClass, Decl(app.ts, 0, 8))
-
-import { MyClass2 } from "./library-b";
->MyClass2 : Symbol(MyClass2, Decl(app.ts, 1, 8))
-
-let x: MyClass;
->x : Symbol(x, Decl(app.ts, 3, 3))
->MyClass : Symbol(MyClass, Decl(app.ts, 0, 8))
-
-let y: MyClass2;
->y : Symbol(y, Decl(app.ts, 4, 3))
->MyClass2 : Symbol(MyClass2, Decl(app.ts, 1, 8))
-
-x = y;
->x : Symbol(x, Decl(app.ts, 3, 3))
->y : Symbol(y, Decl(app.ts, 4, 3))
-
-y = x;
->y : Symbol(y, Decl(app.ts, 4, 3))
->x : Symbol(x, Decl(app.ts, 3, 3))
-
-=== /src/library-a/index.ts ===
-
-export class MyClass{}
->MyClass : Symbol(MyClass, Decl(index.ts, 0, 0))
-
-=== /src/library-b/index.ts ===
-import {MyClass} from "library-a";
->MyClass : Symbol(MyClass, Decl(index.ts, 0, 8))
-
-export { MyClass as MyClass2 }
->MyClass : Symbol(MyClass2, Decl(index.ts, 1, 8))
->MyClass2 : Symbol(MyClass2, Decl(index.ts, 1, 8))
-
diff --git a/tests/baselines/reference/moduleResolutionWithSymlinks.trace.json b/tests/baselines/reference/moduleResolutionWithSymlinks.trace.json
index 7f1c289018096..f3bfae4b17346 100644
--- a/tests/baselines/reference/moduleResolutionWithSymlinks.trace.json
+++ b/tests/baselines/reference/moduleResolutionWithSymlinks.trace.json
@@ -26,7 +26,43 @@
     "File '/src/library-b/node_modules/library-a.tsx' does not exist.",
     "File '/src/library-b/node_modules/library-a.d.ts' does not exist.",
     "File '/src/library-b/node_modules/library-a/package.json' does not exist.",
-    "File '/src/library-b/node_modules/library-a/index.ts' exist - use it as a name resolution result.",
-    "Resolving real path for '/src/library-b/node_modules/library-a/index.ts', result '/src/library-a/index.ts'",
-    "======== Module name 'library-a' was successfully resolved to '/src/library-a/index.ts'. ========"
+    "File '/src/library-b/node_modules/library-a/index.ts' does not exist.",
+    "File '/src/library-b/node_modules/library-a/index.tsx' does not exist.",
+    "File '/src/library-b/node_modules/library-a/index.d.ts' does not exist.",
+    "File '/src/library-b/node_modules/@types/library-a.ts' does not exist.",
+    "File '/src/library-b/node_modules/@types/library-a.tsx' does not exist.",
+    "File '/src/library-b/node_modules/@types/library-a.d.ts' does not exist.",
+    "File '/src/library-b/node_modules/@types/library-a/package.json' does not exist.",
+    "File '/src/library-b/node_modules/@types/library-a/index.ts' does not exist.",
+    "File '/src/library-b/node_modules/@types/library-a/index.tsx' does not exist.",
+    "File '/src/library-b/node_modules/@types/library-a/index.d.ts' does not exist.",
+    "File '/src/node_modules/library-a.ts' does not exist.",
+    "File '/src/node_modules/library-a.tsx' does not exist.",
+    "File '/src/node_modules/library-a.d.ts' does not exist.",
+    "File '/src/node_modules/library-a/package.json' does not exist.",
+    "File '/src/node_modules/library-a/index.ts' does not exist.",
+    "File '/src/node_modules/library-a/index.tsx' does not exist.",
+    "File '/src/node_modules/library-a/index.d.ts' does not exist.",
+    "File '/src/node_modules/@types/library-a.ts' does not exist.",
+    "File '/src/node_modules/@types/library-a.tsx' does not exist.",
+    "File '/src/node_modules/@types/library-a.d.ts' does not exist.",
+    "File '/src/node_modules/@types/library-a/package.json' does not exist.",
+    "File '/src/node_modules/@types/library-a/index.ts' does not exist.",
+    "File '/src/node_modules/@types/library-a/index.tsx' does not exist.",
+    "File '/src/node_modules/@types/library-a/index.d.ts' does not exist.",
+    "File '/node_modules/library-a.ts' does not exist.",
+    "File '/node_modules/library-a.tsx' does not exist.",
+    "File '/node_modules/library-a.d.ts' does not exist.",
+    "File '/node_modules/library-a/package.json' does not exist.",
+    "File '/node_modules/library-a/index.ts' does not exist.",
+    "File '/node_modules/library-a/index.tsx' does not exist.",
+    "File '/node_modules/library-a/index.d.ts' does not exist.",
+    "File '/node_modules/@types/library-a.ts' does not exist.",
+    "File '/node_modules/@types/library-a.tsx' does not exist.",
+    "File '/node_modules/@types/library-a.d.ts' does not exist.",
+    "File '/node_modules/@types/library-a/package.json' does not exist.",
+    "File '/node_modules/@types/library-a/index.ts' does not exist.",
+    "File '/node_modules/@types/library-a/index.tsx' does not exist.",
+    "File '/node_modules/@types/library-a/index.d.ts' does not exist.",
+    "======== Module name 'library-a' was not resolved. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/moduleResolutionWithSymlinks.types b/tests/baselines/reference/moduleResolutionWithSymlinks.types
deleted file mode 100644
index 8344adbe81781..0000000000000
--- a/tests/baselines/reference/moduleResolutionWithSymlinks.types
+++ /dev/null
@@ -1,38 +0,0 @@
-=== /src/app.ts ===
-import { MyClass } from "./library-a";
->MyClass : typeof MyClass
-
-import { MyClass2 } from "./library-b";
->MyClass2 : typeof MyClass
-
-let x: MyClass;
->x : MyClass
->MyClass : MyClass
-
-let y: MyClass2;
->y : MyClass
->MyClass2 : MyClass
-
-x = y;
->x = y : MyClass
->x : MyClass
->y : MyClass
-
-y = x;
->y = x : MyClass
->y : MyClass
->x : MyClass
-
-=== /src/library-a/index.ts ===
-
-export class MyClass{}
->MyClass : MyClass
-
-=== /src/library-b/index.ts ===
-import {MyClass} from "library-a";
->MyClass : typeof MyClass
-
-export { MyClass as MyClass2 }
->MyClass : typeof MyClass
->MyClass2 : typeof MyClass
-
diff --git a/tests/baselines/reference/pathMappingBasedModuleResolution3_node.trace.json b/tests/baselines/reference/pathMappingBasedModuleResolution3_node.trace.json
index af5e20a3cc30c..ab7210d7d020c 100644
--- a/tests/baselines/reference/pathMappingBasedModuleResolution3_node.trace.json
+++ b/tests/baselines/reference/pathMappingBasedModuleResolution3_node.trace.json
@@ -5,11 +5,13 @@
     "Resolving module name 'folder2/file2' relative to base url 'c:/root' - 'c:/root/folder2/file2'.",
     "Loading module as file / folder, candidate module location 'c:/root/folder2/file2'.",
     "File 'c:/root/folder2/file2.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/root/folder2/file2.ts', result 'c:/root/folder2/file2.ts'",
     "======== Module name 'folder2/file2' was successfully resolved to 'c:/root/folder2/file2.ts'. ========",
     "======== Resolving module './file3' from 'c:/root/folder2/file2.ts'. ========",
     "Explicitly specified module resolution kind: 'NodeJs'.",
     "Loading module as file / folder, candidate module location 'c:/root/folder2/file3'.",
     "File 'c:/root/folder2/file3.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/root/folder2/file3.ts', result 'c:/root/folder2/file3.ts'",
     "======== Module name './file3' was successfully resolved to 'c:/root/folder2/file3.ts'. ========",
     "======== Resolving module 'file4' from 'c:/root/folder2/file2.ts'. ========",
     "Explicitly specified module resolution kind: 'NodeJs'.",
@@ -59,5 +61,6 @@
     "File 'c:/node_modules/file4/index.ts' does not exist.",
     "File 'c:/node_modules/file4/index.tsx' does not exist.",
     "File 'c:/node_modules/file4/index.d.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/node_modules/file4/index.d.ts', result 'c:/node_modules/file4/index.d.ts'",
     "======== Module name 'file4' was successfully resolved to 'c:/node_modules/file4/index.d.ts'. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/pathMappingBasedModuleResolution4_node.trace.json b/tests/baselines/reference/pathMappingBasedModuleResolution4_node.trace.json
index af5e20a3cc30c..ab7210d7d020c 100644
--- a/tests/baselines/reference/pathMappingBasedModuleResolution4_node.trace.json
+++ b/tests/baselines/reference/pathMappingBasedModuleResolution4_node.trace.json
@@ -5,11 +5,13 @@
     "Resolving module name 'folder2/file2' relative to base url 'c:/root' - 'c:/root/folder2/file2'.",
     "Loading module as file / folder, candidate module location 'c:/root/folder2/file2'.",
     "File 'c:/root/folder2/file2.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/root/folder2/file2.ts', result 'c:/root/folder2/file2.ts'",
     "======== Module name 'folder2/file2' was successfully resolved to 'c:/root/folder2/file2.ts'. ========",
     "======== Resolving module './file3' from 'c:/root/folder2/file2.ts'. ========",
     "Explicitly specified module resolution kind: 'NodeJs'.",
     "Loading module as file / folder, candidate module location 'c:/root/folder2/file3'.",
     "File 'c:/root/folder2/file3.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/root/folder2/file3.ts', result 'c:/root/folder2/file3.ts'",
     "======== Module name './file3' was successfully resolved to 'c:/root/folder2/file3.ts'. ========",
     "======== Resolving module 'file4' from 'c:/root/folder2/file2.ts'. ========",
     "Explicitly specified module resolution kind: 'NodeJs'.",
@@ -59,5 +61,6 @@
     "File 'c:/node_modules/file4/index.ts' does not exist.",
     "File 'c:/node_modules/file4/index.tsx' does not exist.",
     "File 'c:/node_modules/file4/index.d.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/node_modules/file4/index.d.ts', result 'c:/node_modules/file4/index.d.ts'",
     "======== Module name 'file4' was successfully resolved to 'c:/node_modules/file4/index.d.ts'. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/pathMappingBasedModuleResolution5_node.trace.json b/tests/baselines/reference/pathMappingBasedModuleResolution5_node.trace.json
index cebd59f01b41a..2efeefa24e5ca 100644
--- a/tests/baselines/reference/pathMappingBasedModuleResolution5_node.trace.json
+++ b/tests/baselines/reference/pathMappingBasedModuleResolution5_node.trace.json
@@ -7,6 +7,7 @@
     "Trying substitution '*', candidate module location: 'folder2/file1'.",
     "Loading module as file / folder, candidate module location 'c:/root/folder2/file1'.",
     "File 'c:/root/folder2/file1.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/root/folder2/file1.ts', result 'c:/root/folder2/file1.ts'",
     "======== Module name 'folder2/file1' was successfully resolved to 'c:/root/folder2/file1.ts'. ========",
     "======== Resolving module 'folder3/file2' from 'c:/root/folder1/file1.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
@@ -25,6 +26,7 @@
     "Trying substitution 'generated/*', candidate module location: 'generated/folder3/file2'.",
     "Loading module as file / folder, candidate module location 'c:/root/generated/folder3/file2'.",
     "File 'c:/root/generated/folder3/file2.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/root/generated/folder3/file2.ts', result 'c:/root/generated/folder3/file2.ts'",
     "======== Module name 'folder3/file2' was successfully resolved to 'c:/root/generated/folder3/file2.ts'. ========",
     "======== Resolving module 'components/file3' from 'c:/root/folder1/file1.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
@@ -40,6 +42,7 @@
     "File 'c:/root/shared/components/file3/index.ts' does not exist.",
     "File 'c:/root/shared/components/file3/index.tsx' does not exist.",
     "File 'c:/root/shared/components/file3/index.d.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/root/shared/components/file3/index.d.ts', result 'c:/root/shared/components/file3/index.d.ts'",
     "======== Module name 'components/file3' was successfully resolved to 'c:/root/shared/components/file3/index.d.ts'. ========",
     "======== Resolving module 'file4' from 'c:/root/folder1/file1.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
@@ -94,5 +97,6 @@
     "File 'c:/root/node_modules/@types/file4/index.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/file4/index.d.ts' does not exist.",
     "File 'c:/node_modules/file4.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/node_modules/file4.ts', result 'c:/node_modules/file4.ts'",
     "======== Module name 'file4' was successfully resolved to 'c:/node_modules/file4.ts'. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/pathMappingBasedModuleResolution6_node.trace.json b/tests/baselines/reference/pathMappingBasedModuleResolution6_node.trace.json
index 7c5e76a28474e..28e51a119152d 100644
--- a/tests/baselines/reference/pathMappingBasedModuleResolution6_node.trace.json
+++ b/tests/baselines/reference/pathMappingBasedModuleResolution6_node.trace.json
@@ -18,6 +18,7 @@
     "Loading 'project/file3' from the root dir 'c:/root/generated/src', candidate location 'c:/root/generated/src/project/file3'",
     "Loading module as file / folder, candidate module location 'c:/root/generated/src/project/file3'.",
     "File 'c:/root/generated/src/project/file3.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/root/generated/src/project/file3.ts', result 'c:/root/generated/src/project/file3.ts'",
     "======== Module name './project/file3' was successfully resolved to 'c:/root/generated/src/project/file3.ts'. ========",
     "======== Resolving module '../file2' from 'c:/root/generated/src/project/file3.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
@@ -44,5 +45,6 @@
     "File 'c:/root/src/file2/index.ts' does not exist.",
     "File 'c:/root/src/file2/index.tsx' does not exist.",
     "File 'c:/root/src/file2/index.d.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/root/src/file2/index.d.ts', result 'c:/root/src/file2/index.d.ts'",
     "======== Module name '../file2' was successfully resolved to 'c:/root/src/file2/index.d.ts'. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/pathMappingBasedModuleResolution7_node.trace.json b/tests/baselines/reference/pathMappingBasedModuleResolution7_node.trace.json
index 99d4bf244db23..6be7d349fed69 100644
--- a/tests/baselines/reference/pathMappingBasedModuleResolution7_node.trace.json
+++ b/tests/baselines/reference/pathMappingBasedModuleResolution7_node.trace.json
@@ -18,6 +18,7 @@
     "Loading 'project/file2' from the root dir 'c:/root/generated/src', candidate location 'c:/root/generated/src/project/file2'",
     "Loading module as file / folder, candidate module location 'c:/root/generated/src/project/file2'.",
     "File 'c:/root/generated/src/project/file2.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/root/generated/src/project/file2.ts', result 'c:/root/generated/src/project/file2.ts'",
     "======== Module name './project/file2' was successfully resolved to 'c:/root/generated/src/project/file2.ts'. ========",
     "======== Resolving module 'module3' from 'c:/root/src/file1.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
@@ -74,6 +75,7 @@
     "File 'c:/node_modules/module3.ts' does not exist.",
     "File 'c:/node_modules/module3.tsx' does not exist.",
     "File 'c:/node_modules/module3.d.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/node_modules/module3.d.ts', result 'c:/node_modules/module3.d.ts'",
     "======== Module name 'module3' was successfully resolved to 'c:/node_modules/module3.d.ts'. ========",
     "======== Resolving module 'module1' from 'c:/root/generated/src/project/file2.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
@@ -98,6 +100,7 @@
     "File 'c:/shared/module1/index.ts' does not exist.",
     "File 'c:/shared/module1/index.tsx' does not exist.",
     "File 'c:/shared/module1/index.d.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/shared/module1/index.d.ts', result 'c:/shared/module1/index.d.ts'",
     "======== Module name 'module1' was successfully resolved to 'c:/shared/module1/index.d.ts'. ========",
     "======== Resolving module 'templates/module2' from 'c:/root/generated/src/project/file2.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
@@ -107,6 +110,7 @@
     "Trying substitution 'generated/src/templates/*', candidate module location: 'generated/src/templates/module2'.",
     "Loading module as file / folder, candidate module location 'c:/root/generated/src/templates/module2'.",
     "File 'c:/root/generated/src/templates/module2.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/root/generated/src/templates/module2.ts', result 'c:/root/generated/src/templates/module2.ts'",
     "======== Module name 'templates/module2' was successfully resolved to 'c:/root/generated/src/templates/module2.ts'. ========",
     "======== Resolving module '../file3' from 'c:/root/generated/src/project/file2.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
@@ -133,5 +137,6 @@
     "File 'c:/root/src/file3/index.ts' does not exist.",
     "File 'c:/root/src/file3/index.tsx' does not exist.",
     "File 'c:/root/src/file3/index.d.ts' exist - use it as a name resolution result.",
+    "Resolving real path for 'c:/root/src/file3/index.d.ts', result 'c:/root/src/file3/index.d.ts'",
     "======== Module name '../file3' was successfully resolved to 'c:/root/src/file3/index.d.ts'. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/typeReferenceDirectives1.trace.json b/tests/baselines/reference/typeReferenceDirectives1.trace.json
index c936a84dcc09a..58b23783b0b9d 100644
--- a/tests/baselines/reference/typeReferenceDirectives1.trace.json
+++ b/tests/baselines/reference/typeReferenceDirectives1.trace.json
@@ -1,6 +1,11 @@
 [
-    "======== Resolving type reference directive 'lib', containing file '/app.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
+    "======== Resolving type reference directive 'lib', containing file '/app.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
+    "File '/types/lib/package.json' does not exist.",
+    "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========",
+    "======== Resolving type reference directive 'lib', containing file '/__inferred type names__.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
     "File '/types/lib/package.json' does not exist.",
     "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========"
diff --git a/tests/baselines/reference/typeReferenceDirectives10.trace.json b/tests/baselines/reference/typeReferenceDirectives10.trace.json
index b6adaf1f513f8..61341afdab3a3 100644
--- a/tests/baselines/reference/typeReferenceDirectives10.trace.json
+++ b/tests/baselines/reference/typeReferenceDirectives10.trace.json
@@ -1,6 +1,6 @@
 [
-    "======== Resolving type reference directive 'lib', containing file '/app.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
+    "======== Resolving type reference directive 'lib', containing file '/app.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
     "File '/types/lib/package.json' does not exist.",
     "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========",
@@ -10,5 +10,11 @@
     "File '/ref.ts' does not exist.",
     "File '/ref.tsx' does not exist.",
     "File '/ref.d.ts' exist - use it as a name resolution result.",
-    "======== Module name './ref' was successfully resolved to '/ref.d.ts'. ========"
+    "Resolving real path for '/ref.d.ts', result '/ref.d.ts'",
+    "======== Module name './ref' was successfully resolved to '/ref.d.ts'. ========",
+    "======== Resolving type reference directive 'lib', containing file '/__inferred type names__.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
+    "File '/types/lib/package.json' does not exist.",
+    "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/typeReferenceDirectives11.trace.json b/tests/baselines/reference/typeReferenceDirectives11.trace.json
index bfaae056c9ee2..37fa7900a7c69 100644
--- a/tests/baselines/reference/typeReferenceDirectives11.trace.json
+++ b/tests/baselines/reference/typeReferenceDirectives11.trace.json
@@ -3,9 +3,10 @@
     "Module resolution kind is not specified, using 'NodeJs'.",
     "Loading module as file / folder, candidate module location '/mod1'.",
     "File '/mod1.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/mod1.ts', result '/mod1.ts'",
     "======== Module name './mod1' was successfully resolved to '/mod1.ts'. ========",
-    "======== Resolving type reference directive 'lib', containing file not set, root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
+    "======== Resolving type reference directive 'lib', containing file '/__inferred type names__.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
     "File '/types/lib/package.json' does not exist.",
     "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========"
diff --git a/tests/baselines/reference/typeReferenceDirectives12.trace.json b/tests/baselines/reference/typeReferenceDirectives12.trace.json
index f4fc0937325b9..1024b0cdef3db 100644
--- a/tests/baselines/reference/typeReferenceDirectives12.trace.json
+++ b/tests/baselines/reference/typeReferenceDirectives12.trace.json
@@ -3,14 +3,16 @@
     "Module resolution kind is not specified, using 'NodeJs'.",
     "Loading module as file / folder, candidate module location '/main'.",
     "File '/main.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/main.ts', result '/main.ts'",
     "======== Module name './main' was successfully resolved to '/main.ts'. ========",
     "======== Resolving module './mod1' from '/mod2.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
     "Loading module as file / folder, candidate module location '/mod1'.",
     "File '/mod1.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/mod1.ts', result '/mod1.ts'",
     "======== Module name './mod1' was successfully resolved to '/mod1.ts'. ========",
-    "======== Resolving type reference directive 'lib', containing file '/mod1.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
+    "======== Resolving type reference directive 'lib', containing file '/mod1.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
     "File '/types/lib/package.json' does not exist.",
     "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========",
@@ -18,5 +20,11 @@
     "Module resolution kind is not specified, using 'NodeJs'.",
     "Loading module as file / folder, candidate module location '/main'.",
     "File '/main.ts' exist - use it as a name resolution result.",
-    "======== Module name './main' was successfully resolved to '/main.ts'. ========"
+    "Resolving real path for '/main.ts', result '/main.ts'",
+    "======== Module name './main' was successfully resolved to '/main.ts'. ========",
+    "======== Resolving type reference directive 'lib', containing file '/__inferred type names__.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
+    "File '/types/lib/package.json' does not exist.",
+    "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/typeReferenceDirectives13.trace.json b/tests/baselines/reference/typeReferenceDirectives13.trace.json
index b6adaf1f513f8..61341afdab3a3 100644
--- a/tests/baselines/reference/typeReferenceDirectives13.trace.json
+++ b/tests/baselines/reference/typeReferenceDirectives13.trace.json
@@ -1,6 +1,6 @@
 [
-    "======== Resolving type reference directive 'lib', containing file '/app.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
+    "======== Resolving type reference directive 'lib', containing file '/app.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
     "File '/types/lib/package.json' does not exist.",
     "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========",
@@ -10,5 +10,11 @@
     "File '/ref.ts' does not exist.",
     "File '/ref.tsx' does not exist.",
     "File '/ref.d.ts' exist - use it as a name resolution result.",
-    "======== Module name './ref' was successfully resolved to '/ref.d.ts'. ========"
+    "Resolving real path for '/ref.d.ts', result '/ref.d.ts'",
+    "======== Module name './ref' was successfully resolved to '/ref.d.ts'. ========",
+    "======== Resolving type reference directive 'lib', containing file '/__inferred type names__.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
+    "File '/types/lib/package.json' does not exist.",
+    "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/typeReferenceDirectives2.trace.json b/tests/baselines/reference/typeReferenceDirectives2.trace.json
index 826abe5d51af2..93d3658447dd3 100644
--- a/tests/baselines/reference/typeReferenceDirectives2.trace.json
+++ b/tests/baselines/reference/typeReferenceDirectives2.trace.json
@@ -1,6 +1,6 @@
 [
-    "======== Resolving type reference directive 'lib', containing file not set, root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
+    "======== Resolving type reference directive 'lib', containing file '/__inferred type names__.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
     "File '/types/lib/package.json' does not exist.",
     "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========"
diff --git a/tests/baselines/reference/typeReferenceDirectives3.trace.json b/tests/baselines/reference/typeReferenceDirectives3.trace.json
index c936a84dcc09a..58b23783b0b9d 100644
--- a/tests/baselines/reference/typeReferenceDirectives3.trace.json
+++ b/tests/baselines/reference/typeReferenceDirectives3.trace.json
@@ -1,6 +1,11 @@
 [
-    "======== Resolving type reference directive 'lib', containing file '/app.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
+    "======== Resolving type reference directive 'lib', containing file '/app.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
+    "File '/types/lib/package.json' does not exist.",
+    "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========",
+    "======== Resolving type reference directive 'lib', containing file '/__inferred type names__.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
     "File '/types/lib/package.json' does not exist.",
     "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========"
diff --git a/tests/baselines/reference/typeReferenceDirectives4.trace.json b/tests/baselines/reference/typeReferenceDirectives4.trace.json
index c936a84dcc09a..58b23783b0b9d 100644
--- a/tests/baselines/reference/typeReferenceDirectives4.trace.json
+++ b/tests/baselines/reference/typeReferenceDirectives4.trace.json
@@ -1,6 +1,11 @@
 [
-    "======== Resolving type reference directive 'lib', containing file '/app.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
+    "======== Resolving type reference directive 'lib', containing file '/app.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
+    "File '/types/lib/package.json' does not exist.",
+    "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========",
+    "======== Resolving type reference directive 'lib', containing file '/__inferred type names__.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
     "File '/types/lib/package.json' does not exist.",
     "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========"
diff --git a/tests/baselines/reference/typeReferenceDirectives5.trace.json b/tests/baselines/reference/typeReferenceDirectives5.trace.json
index b6adaf1f513f8..61341afdab3a3 100644
--- a/tests/baselines/reference/typeReferenceDirectives5.trace.json
+++ b/tests/baselines/reference/typeReferenceDirectives5.trace.json
@@ -1,6 +1,6 @@
 [
-    "======== Resolving type reference directive 'lib', containing file '/app.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
+    "======== Resolving type reference directive 'lib', containing file '/app.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
     "File '/types/lib/package.json' does not exist.",
     "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========",
@@ -10,5 +10,11 @@
     "File '/ref.ts' does not exist.",
     "File '/ref.tsx' does not exist.",
     "File '/ref.d.ts' exist - use it as a name resolution result.",
-    "======== Module name './ref' was successfully resolved to '/ref.d.ts'. ========"
+    "Resolving real path for '/ref.d.ts', result '/ref.d.ts'",
+    "======== Module name './ref' was successfully resolved to '/ref.d.ts'. ========",
+    "======== Resolving type reference directive 'lib', containing file '/__inferred type names__.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
+    "File '/types/lib/package.json' does not exist.",
+    "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/typeReferenceDirectives6.trace.json b/tests/baselines/reference/typeReferenceDirectives6.trace.json
index c936a84dcc09a..58b23783b0b9d 100644
--- a/tests/baselines/reference/typeReferenceDirectives6.trace.json
+++ b/tests/baselines/reference/typeReferenceDirectives6.trace.json
@@ -1,6 +1,11 @@
 [
-    "======== Resolving type reference directive 'lib', containing file '/app.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
+    "======== Resolving type reference directive 'lib', containing file '/app.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
+    "File '/types/lib/package.json' does not exist.",
+    "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========",
+    "======== Resolving type reference directive 'lib', containing file '/__inferred type names__.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
     "File '/types/lib/package.json' does not exist.",
     "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========"
diff --git a/tests/baselines/reference/typeReferenceDirectives7.trace.json b/tests/baselines/reference/typeReferenceDirectives7.trace.json
index c936a84dcc09a..58b23783b0b9d 100644
--- a/tests/baselines/reference/typeReferenceDirectives7.trace.json
+++ b/tests/baselines/reference/typeReferenceDirectives7.trace.json
@@ -1,6 +1,11 @@
 [
-    "======== Resolving type reference directive 'lib', containing file '/app.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
+    "======== Resolving type reference directive 'lib', containing file '/app.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
+    "File '/types/lib/package.json' does not exist.",
+    "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========",
+    "======== Resolving type reference directive 'lib', containing file '/__inferred type names__.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
     "File '/types/lib/package.json' does not exist.",
     "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========"
diff --git a/tests/baselines/reference/typeReferenceDirectives8.trace.json b/tests/baselines/reference/typeReferenceDirectives8.trace.json
index bfaae056c9ee2..37fa7900a7c69 100644
--- a/tests/baselines/reference/typeReferenceDirectives8.trace.json
+++ b/tests/baselines/reference/typeReferenceDirectives8.trace.json
@@ -3,9 +3,10 @@
     "Module resolution kind is not specified, using 'NodeJs'.",
     "Loading module as file / folder, candidate module location '/mod1'.",
     "File '/mod1.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/mod1.ts', result '/mod1.ts'",
     "======== Module name './mod1' was successfully resolved to '/mod1.ts'. ========",
-    "======== Resolving type reference directive 'lib', containing file not set, root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
+    "======== Resolving type reference directive 'lib', containing file '/__inferred type names__.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
     "File '/types/lib/package.json' does not exist.",
     "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========"
diff --git a/tests/baselines/reference/typeReferenceDirectives9.trace.json b/tests/baselines/reference/typeReferenceDirectives9.trace.json
index f4fc0937325b9..1024b0cdef3db 100644
--- a/tests/baselines/reference/typeReferenceDirectives9.trace.json
+++ b/tests/baselines/reference/typeReferenceDirectives9.trace.json
@@ -3,14 +3,16 @@
     "Module resolution kind is not specified, using 'NodeJs'.",
     "Loading module as file / folder, candidate module location '/main'.",
     "File '/main.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/main.ts', result '/main.ts'",
     "======== Module name './main' was successfully resolved to '/main.ts'. ========",
     "======== Resolving module './mod1' from '/mod2.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
     "Loading module as file / folder, candidate module location '/mod1'.",
     "File '/mod1.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/mod1.ts', result '/mod1.ts'",
     "======== Module name './mod1' was successfully resolved to '/mod1.ts'. ========",
-    "======== Resolving type reference directive 'lib', containing file '/mod1.ts', root directory '/'. ========",
-    "Resolving with primary search path '/types/'",
+    "======== Resolving type reference directive 'lib', containing file '/mod1.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
     "File '/types/lib/package.json' does not exist.",
     "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========",
@@ -18,5 +20,11 @@
     "Module resolution kind is not specified, using 'NodeJs'.",
     "Loading module as file / folder, candidate module location '/main'.",
     "File '/main.ts' exist - use it as a name resolution result.",
-    "======== Module name './main' was successfully resolved to '/main.ts'. ========"
+    "Resolving real path for '/main.ts', result '/main.ts'",
+    "======== Module name './main' was successfully resolved to '/main.ts'. ========",
+    "======== Resolving type reference directive 'lib', containing file '/__inferred type names__.ts', root directory '/types'. ========",
+    "Resolving with primary search path '/types'",
+    "File '/types/lib/package.json' does not exist.",
+    "File '/types/lib/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'lib' was successfully resolved to '/types/lib/index.d.ts', primary: true. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/typingsLookup1.js b/tests/baselines/reference/typingsLookup1.js
index 1f89a2277aade..3927c3db0778d 100644
--- a/tests/baselines/reference/typingsLookup1.js
+++ b/tests/baselines/reference/typingsLookup1.js
@@ -4,8 +4,10 @@
 declare var $: { x: any };
 
 //// [a.ts]
+/// <reference types="jquery" />
 $.x;
 
 
 //// [a.js]
+/// <reference types="jquery" />
 $.x;
diff --git a/tests/baselines/reference/typingsLookup1.symbols b/tests/baselines/reference/typingsLookup1.symbols
index 8a21252d1237d..73d01df511e91 100644
--- a/tests/baselines/reference/typingsLookup1.symbols
+++ b/tests/baselines/reference/typingsLookup1.symbols
@@ -1,10 +1,11 @@
-=== tests/cases/conformance/typings/a.ts ===
+=== /a.ts ===
+/// <reference types="jquery" />
 $.x;
 >$.x : Symbol(x, Decl(index.d.ts, 0, 16))
 >$ : Symbol($, Decl(index.d.ts, 0, 11))
 >x : Symbol(x, Decl(index.d.ts, 0, 16))
 
-=== tests/cases/conformance/typings/node_modules/@types/jquery/index.d.ts ===
+=== /node_modules/@types/jquery/index.d.ts ===
 declare var $: { x: any };
 >$ : Symbol($, Decl(index.d.ts, 0, 11))
 >x : Symbol(x, Decl(index.d.ts, 0, 16))
diff --git a/tests/baselines/reference/typingsLookup1.trace.json b/tests/baselines/reference/typingsLookup1.trace.json
new file mode 100644
index 0000000000000..0463c920bd323
--- /dev/null
+++ b/tests/baselines/reference/typingsLookup1.trace.json
@@ -0,0 +1,18 @@
+[
+    "======== Resolving type reference directive 'jquery', containing file '/a.ts', root directory 'node_modules/@types'. ========",
+    "Resolving with primary search path 'node_modules/@types'",
+    "File 'node_modules/@types/jquery/package.json' does not exist.",
+    "File 'node_modules/@types/jquery/index.d.ts' does not exist.",
+    "Looking up in 'node_modules' folder, initial location '/'",
+    "File '/node_modules/jquery.ts' does not exist.",
+    "File '/node_modules/jquery.d.ts' does not exist.",
+    "File '/node_modules/jquery/package.json' does not exist.",
+    "File '/node_modules/jquery/index.ts' does not exist.",
+    "File '/node_modules/jquery/index.d.ts' does not exist.",
+    "File '/node_modules/@types/jquery.ts' does not exist.",
+    "File '/node_modules/@types/jquery.d.ts' does not exist.",
+    "File '/node_modules/@types/jquery/package.json' does not exist.",
+    "File '/node_modules/@types/jquery/index.ts' does not exist.",
+    "File '/node_modules/@types/jquery/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'jquery' was successfully resolved to '/node_modules/@types/jquery/index.d.ts', primary: false. ========"
+]
\ No newline at end of file
diff --git a/tests/baselines/reference/typingsLookup1.types b/tests/baselines/reference/typingsLookup1.types
index ca79a8248d5db..e1b696bf343c7 100644
--- a/tests/baselines/reference/typingsLookup1.types
+++ b/tests/baselines/reference/typingsLookup1.types
@@ -1,10 +1,11 @@
-=== tests/cases/conformance/typings/a.ts ===
+=== /a.ts ===
+/// <reference types="jquery" />
 $.x;
 >$.x : any
 >$ : { x: any; }
 >x : any
 
-=== tests/cases/conformance/typings/node_modules/@types/jquery/index.d.ts ===
+=== /node_modules/@types/jquery/index.d.ts ===
 declare var $: { x: any };
 >$ : { x: any; }
 >x : any
diff --git a/tests/cases/compiler/commonSourceDir5.ts b/tests/cases/compiler/commonSourceDir5.ts
index d181bef68fe01..7f5239976e879 100644
--- a/tests/cases/compiler/commonSourceDir5.ts
+++ b/tests/cases/compiler/commonSourceDir5.ts
@@ -1,6 +1,7 @@
 // @outFile: concat.js
 // @module: amd
 // @moduleResolution: node
+
 // @Filename: A:/bar.ts
 import {z} from "./foo";
 export var x = z + z;
diff --git a/tests/cases/compiler/typeReferenceDirectives1.ts b/tests/cases/compiler/typeReferenceDirectives1.ts
index 2127bd13f7b0d..e17e498b9784d 100644
--- a/tests/cases/compiler/typeReferenceDirectives1.ts
+++ b/tests/cases/compiler/typeReferenceDirectives1.ts
@@ -1,7 +1,7 @@
 // @noImplicitReferences: true
 // @traceResolution: true
 // @declaration: true
-// @typesRoot: /
+// @typeRoots: /types
 
 
 // @filename: /types/lib/index.d.ts
diff --git a/tests/cases/compiler/typeReferenceDirectives10.ts b/tests/cases/compiler/typeReferenceDirectives10.ts
index bf0768993c9e5..61971ba44b2ad 100644
--- a/tests/cases/compiler/typeReferenceDirectives10.ts
+++ b/tests/cases/compiler/typeReferenceDirectives10.ts
@@ -1,6 +1,6 @@
 // @noImplicitReferences: true
 // @declaration: true
-// @typesRoot: /
+// @typeRoots: /types
 // @traceResolution: true
 
 // @filename: /ref.d.ts
diff --git a/tests/cases/compiler/typeReferenceDirectives11.ts b/tests/cases/compiler/typeReferenceDirectives11.ts
index c955a5daffcf8..2d93e22bdcf23 100644
--- a/tests/cases/compiler/typeReferenceDirectives11.ts
+++ b/tests/cases/compiler/typeReferenceDirectives11.ts
@@ -1,6 +1,6 @@
 // @noImplicitReferences: true
 // @declaration: true
-// @typesRoot: /
+// @typeRoots: /types
 // @traceResolution: true
 // @types: lib
 // @out: output.js
diff --git a/tests/cases/compiler/typeReferenceDirectives12.ts b/tests/cases/compiler/typeReferenceDirectives12.ts
index ef3c8d9755f6d..efdb1e8312b6f 100644
--- a/tests/cases/compiler/typeReferenceDirectives12.ts
+++ b/tests/cases/compiler/typeReferenceDirectives12.ts
@@ -1,6 +1,6 @@
 // @noImplicitReferences: true
 // @declaration: true
-// @typesRoot: /
+// @typeRoots: /types
 // @traceResolution: true
 // @out: output.js
 
diff --git a/tests/cases/compiler/typeReferenceDirectives13.ts b/tests/cases/compiler/typeReferenceDirectives13.ts
index 816d419e9d540..124c31274ace4 100644
--- a/tests/cases/compiler/typeReferenceDirectives13.ts
+++ b/tests/cases/compiler/typeReferenceDirectives13.ts
@@ -1,6 +1,6 @@
 // @noImplicitReferences: true
 // @declaration: true
-// @typesRoot: /
+// @typeRoots: /types
 // @traceResolution: true
 
 // @filename: /ref.d.ts
diff --git a/tests/cases/compiler/typeReferenceDirectives2.ts b/tests/cases/compiler/typeReferenceDirectives2.ts
index eb651728cea81..31a01a0b8e4bc 100644
--- a/tests/cases/compiler/typeReferenceDirectives2.ts
+++ b/tests/cases/compiler/typeReferenceDirectives2.ts
@@ -1,7 +1,7 @@
 // @noImplicitReferences: true
 // @traceResolution: true
 // @declaration: true
-// @typesRoot: /
+// @typeRoots: /types
 // @types: lib
 
 // @filename: /types/lib/index.d.ts
diff --git a/tests/cases/compiler/typeReferenceDirectives3.ts b/tests/cases/compiler/typeReferenceDirectives3.ts
index bf81268d141c4..4c2729ab389b3 100644
--- a/tests/cases/compiler/typeReferenceDirectives3.ts
+++ b/tests/cases/compiler/typeReferenceDirectives3.ts
@@ -1,6 +1,6 @@
 // @noImplicitReferences: true
 // @declaration: true
-// @typesRoot: /
+// @typeRoots: /types
 // @traceResolution: true
 
 // $ comes from d.ts file - no need to add type reference directive
diff --git a/tests/cases/compiler/typeReferenceDirectives4.ts b/tests/cases/compiler/typeReferenceDirectives4.ts
index 48eb8a5324a11..ac7346895ef7d 100644
--- a/tests/cases/compiler/typeReferenceDirectives4.ts
+++ b/tests/cases/compiler/typeReferenceDirectives4.ts
@@ -1,7 +1,7 @@
 // @noImplicitReferences: true
 // @traceResolution: true
 // @declaration: true
-// @typesRoot: /
+// @typeRoots: /types
 
 // $ comes from d.ts file - no need to add type reference directive
 
diff --git a/tests/cases/compiler/typeReferenceDirectives5.ts b/tests/cases/compiler/typeReferenceDirectives5.ts
index 675f932da68b9..bb24b82b32466 100644
--- a/tests/cases/compiler/typeReferenceDirectives5.ts
+++ b/tests/cases/compiler/typeReferenceDirectives5.ts
@@ -1,7 +1,7 @@
 // @noImplicitReferences: true
 // @traceResolution: true
 // @declaration: true
-// @typesRoot: /
+// @typeRoots: /types
 
 // @filename: /ref.d.ts
 export interface $ { x }
diff --git a/tests/cases/compiler/typeReferenceDirectives6.ts b/tests/cases/compiler/typeReferenceDirectives6.ts
index 120a743009ce2..7154963f1efa3 100644
--- a/tests/cases/compiler/typeReferenceDirectives6.ts
+++ b/tests/cases/compiler/typeReferenceDirectives6.ts
@@ -1,7 +1,7 @@
 // @noImplicitReferences: true
 // @traceResolution: true
 // @declaration: true
-// @typesRoot: /
+// @typeRoots: /types
 
 // $ comes from type declaration file - type reference directive should be added
 
diff --git a/tests/cases/compiler/typeReferenceDirectives7.ts b/tests/cases/compiler/typeReferenceDirectives7.ts
index f18fed37741d7..79d42fa701853 100644
--- a/tests/cases/compiler/typeReferenceDirectives7.ts
+++ b/tests/cases/compiler/typeReferenceDirectives7.ts
@@ -1,7 +1,7 @@
 // @noImplicitReferences: true
 // @traceResolution: true
 // @declaration: true
-// @typesRoot: /
+// @typeRoots: /types
 
 // local value shadows global - no need to add type reference directive 
    
diff --git a/tests/cases/compiler/typeReferenceDirectives8.ts b/tests/cases/compiler/typeReferenceDirectives8.ts
index 2465d2afb10db..c7725a3aab1ab 100644
--- a/tests/cases/compiler/typeReferenceDirectives8.ts
+++ b/tests/cases/compiler/typeReferenceDirectives8.ts
@@ -1,6 +1,6 @@
 // @noImplicitReferences: true
 // @declaration: true
-// @typesRoot: /
+// @typeRoots: /types
 // @traceResolution: true
 // @types: lib
 
diff --git a/tests/cases/compiler/typeReferenceDirectives9.ts b/tests/cases/compiler/typeReferenceDirectives9.ts
index eb8d6abaef1c0..610c7173c898b 100644
--- a/tests/cases/compiler/typeReferenceDirectives9.ts
+++ b/tests/cases/compiler/typeReferenceDirectives9.ts
@@ -1,6 +1,6 @@
 // @noImplicitReferences: true
 // @declaration: true
-// @typesRoot: /
+// @typeRoots: /types
 // @traceResolution: true
 
 // @filename: /types/lib/index.d.ts
diff --git a/tests/cases/conformance/references/library-reference-1.ts b/tests/cases/conformance/references/library-reference-1.ts
index ca25441521fcc..c6b6cea36efab 100644
--- a/tests/cases/conformance/references/library-reference-1.ts
+++ b/tests/cases/conformance/references/library-reference-1.ts
@@ -1,13 +1,14 @@
 // @noImplicitReferences: true
 // @traceResolution: true
-// @typesRoot: /
+// @currentDirectory: /src
+// @typeRoots: types
 
 // We can find typings in the ./types folder
 
-// @filename: /types/jquery/index.d.ts
+// @filename: /src/types/jquery/index.d.ts
 declare var $: { foo(): void };
 
 
-// @filename: /consumer.ts
+// @filename: /src/consumer.ts
 /// <reference types="jquery" />
 $.foo();
diff --git a/tests/cases/conformance/references/library-reference-10.ts b/tests/cases/conformance/references/library-reference-10.ts
index 11e065b0a7db9..bc9ec99edcf56 100644
--- a/tests/cases/conformance/references/library-reference-10.ts
+++ b/tests/cases/conformance/references/library-reference-10.ts
@@ -1,18 +1,19 @@
 // @noImplicitReferences: true
 // @traceResolution: true
-// @typesRoot: /
+// @currentDirectory: /foo
+// @typeRoots: ./types
 
 // package.json in a primary reference can refer to another file
 
-// @filename: /types/jquery/package.json
+// @filename: /foo/types/jquery/package.json
 {
     "typings": "jquery.d.ts"
 }
 
-// @filename: /types/jquery/jquery.d.ts
+// @filename: /foo/types/jquery/jquery.d.ts
 declare var $: { foo(): void };
 
 
-// @filename: /consumer.ts
+// @filename: /foo/consumer.ts
 /// <reference types="jquery" />
 $.foo();
diff --git a/tests/cases/conformance/references/library-reference-13.ts b/tests/cases/conformance/references/library-reference-13.ts
index a96437f9b2c3b..92b4b259ba4a9 100644
--- a/tests/cases/conformance/references/library-reference-13.ts
+++ b/tests/cases/conformance/references/library-reference-13.ts
@@ -6,7 +6,8 @@
 // @filename: /a/tsconfig.json
 {
     "compilerOptions": {
-        "types": [ "jquery" ]
+        "types": [ "jquery" ],
+        "typeRoots": ["/a/types"]
     }
 }
 
diff --git a/tests/cases/conformance/references/library-reference-14.ts b/tests/cases/conformance/references/library-reference-14.ts
index 53bca2ab40d16..fa4a63cfcc034 100644
--- a/tests/cases/conformance/references/library-reference-14.ts
+++ b/tests/cases/conformance/references/library-reference-14.ts
@@ -1,7 +1,8 @@
 // @noImplicitReferences: true
 // @traceResolution: true
 // @types: jquery
-// @typesRoot: /a
+// @typeRoots: /a/types
+// @currentDirectory: /a
 
 // @filename: /a/types/jquery/index.d.ts
 declare var $: { foo(): void };
diff --git a/tests/cases/conformance/references/library-reference-15.ts b/tests/cases/conformance/references/library-reference-15.ts
index dd2179d1af660..417012a4539c9 100644
--- a/tests/cases/conformance/references/library-reference-15.ts
+++ b/tests/cases/conformance/references/library-reference-15.ts
@@ -1,11 +1,15 @@
 // @noImplicitReferences: true
 // @traceResolution: true
 // @types: jquery
-// @currentDirectory: /
+// @currentDirectory: /a
+// @typeRoots: types
 
 // @filename: /a/types/jquery/index.d.ts
 declare var $: { foo(): void };
 
+// @filename: /a/types/jquery2/index.d.ts
+declare var $2: { foo(): void };
 
 // @filename: /a/b/consumer.ts
-$.foo();
+$.foo(); // should OK
+$2.foo(); // should error
\ No newline at end of file
diff --git a/tests/cases/conformance/references/library-reference-2.ts b/tests/cases/conformance/references/library-reference-2.ts
index d8975664428cb..9ac7cd4f4d321 100644
--- a/tests/cases/conformance/references/library-reference-2.ts
+++ b/tests/cases/conformance/references/library-reference-2.ts
@@ -1,6 +1,7 @@
 // @noImplicitReferences: true
 // @traceResolution: true
-// @typesRoot: /
+// @typeRoots: /types
+// @currentDirectory: test
 
 // package.json in a primary reference can refer to another file
 
diff --git a/tests/cases/conformance/references/library-reference-3.ts b/tests/cases/conformance/references/library-reference-3.ts
index 1af6df89d19d6..88ef916eaaeba 100644
--- a/tests/cases/conformance/references/library-reference-3.ts
+++ b/tests/cases/conformance/references/library-reference-3.ts
@@ -1,6 +1,6 @@
 // @noImplicitReferences: true
 // @traceResolution: true
-// @typesRoot: /src
+// @currentDirectory: /src
 
 // Secondary references are possible
 
diff --git a/tests/cases/conformance/references/library-reference-4.ts b/tests/cases/conformance/references/library-reference-4.ts
index 92f1b4008beb6..9a615f470efff 100644
--- a/tests/cases/conformance/references/library-reference-4.ts
+++ b/tests/cases/conformance/references/library-reference-4.ts
@@ -1,6 +1,7 @@
 // @noImplicitReferences: true
 // @traceResolution: true
-// @typesRoot: /src
+// @typeRoots: /src
+// @currentDirectory: test
 
 // Secondary references may be duplicated if they agree in content
 
diff --git a/tests/cases/conformance/references/library-reference-5.ts b/tests/cases/conformance/references/library-reference-5.ts
index 1fe327a1c693a..dd72da36dd0a3 100644
--- a/tests/cases/conformance/references/library-reference-5.ts
+++ b/tests/cases/conformance/references/library-reference-5.ts
@@ -1,6 +1,7 @@
 // @noImplicitReferences: true
 // @traceResolution: true
 // @currentDirectory: /
+// @typeRoots: types
 
 // Secondary references may not be duplicated if they disagree in content
 
diff --git a/tests/cases/conformance/references/library-reference-6.ts b/tests/cases/conformance/references/library-reference-6.ts
index a746262dd73b1..765a6760aa49d 100644
--- a/tests/cases/conformance/references/library-reference-6.ts
+++ b/tests/cases/conformance/references/library-reference-6.ts
@@ -1,9 +1,10 @@
 // @noImplicitReferences: true
 // @traceResolution: true
+// @currentDirectory: /
 
 // The primary lookup folder is relative to tsconfig.json, if present
 
-// @filename: /types/alpha/index.d.ts
+// @filename: /node_modules/@types/alpha/index.d.ts
 declare var alpha: { a: string };
 
 // @filename: /src/foo.ts
@@ -12,4 +13,7 @@ var x: string = alpha.a;
 
 // @filename: /tsconfig.json
 {
+	"compilerOptions": {
+		"typesRoot": "types"
+	}
 }
diff --git a/tests/cases/conformance/references/library-reference-8.ts b/tests/cases/conformance/references/library-reference-8.ts
index 9de93776989b5..1c4ab76f8a10e 100644
--- a/tests/cases/conformance/references/library-reference-8.ts
+++ b/tests/cases/conformance/references/library-reference-8.ts
@@ -1,18 +1,19 @@
 // @noImplicitReferences: true
 // @traceResolution: true
-// @typesRoot: /
+// @typeRoots: /test/types
+// @currentDirectory: /test
 
 // Don't crash in circular library reference situations
 
-// @filename: /types/alpha/index.d.ts
+// @filename: /test/types/alpha/index.d.ts
 /// <reference types="beta" />
 declare var alpha: { a: string };
 
-// @filename: /types/beta/index.d.ts
+// @filename: /test/types/beta/index.d.ts
 /// <reference types="alpha" />
 declare var beta: { b: string };
 
-// @filename: /foo.ts
+// @filename: /test/foo.ts
 /// <reference types="alpha" />
 /// <reference types="beta" />
 var x: string = alpha.a + beta.b;
diff --git a/tests/cases/conformance/references/library-reference-9.ts b/tests/cases/conformance/references/library-reference-9.ts
deleted file mode 100644
index a187d3c23b91f..0000000000000
--- a/tests/cases/conformance/references/library-reference-9.ts
+++ /dev/null
@@ -1,20 +0,0 @@
-// @noImplicitReferences: true
-// @traceResolution: true
-
-// Use types search path
-
-// @filename: /share/typelib/alpha/index.d.ts
-declare var alpha: { a: string };
-
-// @filename: /base/src/foo.ts
-/// <reference types="alpha" />
-var x: string = alpha.a;
-
-// @filename: /tsconfig.json
-{
-    "compilerOptions": {
-        "typesSearchPaths": [
-            "./share/typelib"
-        ]
-    }
-}
diff --git a/tests/cases/conformance/typings/typingsLookup1.ts b/tests/cases/conformance/typings/typingsLookup1.ts
index 702bd4bc21cff..555d4569af34d 100644
--- a/tests/cases/conformance/typings/typingsLookup1.ts
+++ b/tests/cases/conformance/typings/typingsLookup1.ts
@@ -1,10 +1,12 @@
+// @traceResolution: true
 // @noImplicitReferences: true
 
-// @filename: tsconfig.json
+// @filename: /tsconfig.json
 { "files": "a.ts" }
 
-// @filename: node_modules/@types/jquery/index.d.ts
+// @filename: /node_modules/@types/jquery/index.d.ts
 declare var $: { x: any };
 
-// @filename: a.ts
+// @filename: /a.ts
+/// <reference types="jquery" />
 $.x;
diff --git a/tests/cases/fourslash/goToDefinitionTypeReferenceDirective.ts b/tests/cases/fourslash/goToDefinitionTypeReferenceDirective.ts
index 3aaa3ab980f08..78dfa94c5e44a 100644
--- a/tests/cases/fourslash/goToDefinitionTypeReferenceDirective.ts
+++ b/tests/cases/fourslash/goToDefinitionTypeReferenceDirective.ts
@@ -1,6 +1,6 @@
 /// <reference path="fourslash.ts"/>
 
-// @typesRoot: src
+// @typeRoots: src/types
 // @Filename: src/types/lib/index.d.ts
 /////*0*/declare let $: {x: number};
 
diff --git a/tests/cases/fourslash/shims-pp/goToDefinitionTypeReferenceDirective.ts b/tests/cases/fourslash/shims-pp/goToDefinitionTypeReferenceDirective.ts
index 3aaa3ab980f08..78dfa94c5e44a 100644
--- a/tests/cases/fourslash/shims-pp/goToDefinitionTypeReferenceDirective.ts
+++ b/tests/cases/fourslash/shims-pp/goToDefinitionTypeReferenceDirective.ts
@@ -1,6 +1,6 @@
 /// <reference path="fourslash.ts"/>
 
-// @typesRoot: src
+// @typeRoots: src/types
 // @Filename: src/types/lib/index.d.ts
 /////*0*/declare let $: {x: number};
 
diff --git a/tests/cases/fourslash/shims/goToDefinitionTypeReferenceDirective.ts b/tests/cases/fourslash/shims/goToDefinitionTypeReferenceDirective.ts
index 3aaa3ab980f08..dc2fc356c57aa 100644
--- a/tests/cases/fourslash/shims/goToDefinitionTypeReferenceDirective.ts
+++ b/tests/cases/fourslash/shims/goToDefinitionTypeReferenceDirective.ts
@@ -1,6 +1,6 @@
-/// <reference path="fourslash.ts"/>
+/// <reference path="../fourslash.ts"/>
 
-// @typesRoot: src
+// @typeRoots: src/types
 // @Filename: src/types/lib/index.d.ts
 /////*0*/declare let $: {x: number};
 
diff --git a/tests/cases/unittests/moduleResolution.ts b/tests/cases/unittests/moduleResolution.ts
index ab5eddc0997c9..16fc7df8d70da 100644
--- a/tests/cases/unittests/moduleResolution.ts
+++ b/tests/cases/unittests/moduleResolution.ts
@@ -314,6 +314,7 @@ namespace ts {
                 getDefaultLibFileName: () => "lib.d.ts",
                 writeFile: (fileName, content): void => { throw new Error("NotImplemented"); },
                 getCurrentDirectory: () => currentDirectory,
+                getDirectories: () => [],
                 getCanonicalFileName: fileName => fileName.toLowerCase(),
                 getNewLine: () => "\r\n",
                 useCaseSensitiveFileNames: () => false,
@@ -397,6 +398,7 @@ export = C;
                 getDefaultLibFileName: () => "lib.d.ts",
                 writeFile: (fileName, content): void => { throw new Error("NotImplemented"); },
                 getCurrentDirectory: () => currentDirectory,
+                getDirectories: () => [],
                 getCanonicalFileName,
                 getNewLine: () => "\r\n",
                 useCaseSensitiveFileNames: () => useCaseSensitiveFileNames,
@@ -955,7 +957,7 @@ import b = require("./moduleB.ts");
     describe("Type reference directive resolution: ", () => {
         function test(typesRoot: string, typeDirective: string, primary: boolean, initialFile: File, targetFile: File, ...otherFiles: File[]) {
             const host = createModuleResolutionHost(/*hasDirectoryExists*/ false, ...[initialFile, targetFile].concat(...otherFiles));
-            const result = resolveTypeReferenceDirective(typeDirective, initialFile.name, {typesRoot}, host);
+            const result = resolveTypeReferenceDirective(typeDirective, initialFile.name, {typeRoots: [typesRoot]}, host);
             assert(result.resolvedTypeReferenceDirective.resolvedFileName !== undefined, "expected type directive to be resolved");
             assert.equal(result.resolvedTypeReferenceDirective.resolvedFileName, targetFile.name, "unexpected result of type reference resolution");
             assert.equal(result.resolvedTypeReferenceDirective.primary, primary, "unexpected 'primary' value");
@@ -965,64 +967,64 @@ import b = require("./moduleB.ts");
             {
                 const f1 = { name: "/root/src/app.ts" };
                 const f2 = { name: "/root/src/types/lib/index.d.ts" };
-                test(/*typesRoot*/"/root/src", /* typeDirective */"lib", /*primary*/ true, f1, f2);
+                test(/*typesRoot*/"/root/src/types", /* typeDirective */"lib", /*primary*/ true, f1, f2);
             }
             {
                 const f1 = { name: "/root/src/app.ts" };
                 const f2 = { name: "/root/src/types/lib/typings/lib.d.ts" };
                 const package = { name: "/root/src/types/lib/package.json", content: JSON.stringify({types: "typings/lib.d.ts"}) };
-                test(/*typesRoot*/"/root/src", /* typeDirective */"lib", /*primary*/ true, f1, f2, package);
+                test(/*typesRoot*/"/root/src/types", /* typeDirective */"lib", /*primary*/ true, f1, f2, package);
             }
             {
                 const f1 = { name: "/root/src/app.ts" };
                 const f2 = { name: "/root/src/node_modules/lib/index.d.ts" };
-                test(/*typesRoot*/"/root/src", /* typeDirective */"lib", /*primary*/ true, f1, f2);
+                test(/*typesRoot*/"/root/src/types", /* typeDirective */"lib", /*primary*/ false, f1, f2);
             }
             {
                 const f1 = { name: "/root/src/app.ts" };
                 const f2 = { name: "/root/src/node_modules/lib/typings/lib.d.ts" };
                 const package = { name: "/root/src/node_modules/lib/package.json", content: JSON.stringify({types: "typings/lib.d.ts"}) };
-                test(/*typesRoot*/"/root/src", /* typeDirective */"lib", /*primary*/ true, f1, f2, package);
+                test(/*typesRoot*/"/root/src/types", /* typeDirective */"lib", /*primary*/ false, f1, f2, package);
             }
             {
                 const f1 = { name: "/root/src/app.ts" };
                 const f2 = { name: "/root/src/node_modules/@types/lib/index.d.ts" };
-                test(/*typesRoot*/"/root/src", /* typeDirective */"lib", /*primary*/ true, f1, f2);
+                test(/*typesRoot*/"/root/src/types", /* typeDirective */"lib", /*primary*/ false, f1, f2);
             }
             {
                 const f1 = { name: "/root/src/app.ts" };
                 const f2 = { name: "/root/src/node_modules/@types/lib/typings/lib.d.ts" };
                 const package = { name: "/root/src/node_modules/@types/lib/package.json", content: JSON.stringify({types: "typings/lib.d.ts"}) };
-                test(/*typesRoot*/"/root/src", /* typeDirective */"lib", /*primary*/ true, f1, f2, package);
+                test(/*typesRoot*/"/root/src/types", /* typeDirective */"lib", /*primary*/ false, f1, f2, package);
             }
         });
         it("Can be resolved from secondary location", () => {
             {
                 const f1 = { name: "/root/src/app.ts" };
                 const f2 = { name: "/root/node_modules/lib.d.ts" };
-                test(/*typesRoot*/"/root/src", /* typeDirective */"lib", /*primary*/ false, f1, f2);
+                test(/*typesRoot*/"/root/src/types", /* typeDirective */"lib", /*primary*/ false, f1, f2);
             }
             {
                 const f1 = { name: "/root/src/app.ts" };
                 const f2 = { name: "/root/node_modules/lib/index.d.ts" };
-                test(/*typesRoot*/"/root/src", /* typeDirective */"lib", /*primary*/ false, f1, f2);
+                test(/*typesRoot*/"/root/src/types", /* typeDirective */"lib", /*primary*/ false, f1, f2);
             }
             {
                 const f1 = { name: "/root/src/app.ts" };
                 const f2 = { name: "/root/node_modules/lib/typings/lib.d.ts" };
                 const package = { name: "/root/node_modules/lib/package.json", content: JSON.stringify({typings: "typings/lib.d.ts"}) };
-                test(/*typesRoot*/"/root/src", /* typeDirective */"lib", /*primary*/ false, f1, f2, package);
+                test(/*typesRoot*/"/root/src/types", /* typeDirective */"lib", /*primary*/ false, f1, f2, package);
             }
             {
                 const f1 = { name: "/root/src/app.ts" };
                 const f2 = { name: "/root/node_modules/@types/lib/index.d.ts" };
-                test(/*typesRoot*/"/root/src", /* typeDirective */"lib", /*primary*/ false, f1, f2);
+                test(/*typesRoot*/"/root/src/types", /* typeDirective */"lib", /*primary*/ false, f1, f2);
             }
             {
                 const f1 = { name: "/root/src/app.ts" };
                 const f2 = { name: "/root/node_modules/@types/lib/typings/lib.d.ts" };
                 const package = { name: "/root/node_modules/@types/lib/package.json", content: JSON.stringify({typings: "typings/lib.d.ts"}) };
-                test(/*typesRoot*/"/root/src", /* typeDirective */"lib", /*primary*/ false, f1, f2, package);
+                test(/*typesRoot*/"/root/src/types", /* typeDirective */"lib", /*primary*/ false, f1, f2, package);
             }
         });
         it("Primary resolution overrides secondary resolutions", () => {
@@ -1030,7 +1032,7 @@ import b = require("./moduleB.ts");
                 const f1 = { name: "/root/src/a/b/c/app.ts" };
                 const f2 = { name: "/root/src/types/lib/index.d.ts" };
                 const f3 = { name: "/root/src/a/b/node_modules/lib.d.ts" };
-                test(/*typesRoot*/"/root/src", /* typeDirective */"lib", /*primary*/ true, f1, f2, f3);
+                test(/*typesRoot*/"/root/src/types", /* typeDirective */"lib", /*primary*/ true, f1, f2, f3);
             }
         });
         it("Reused program keeps errors", () => {
@@ -1050,6 +1052,7 @@ import b = require("./moduleB.ts");
                     throw new Error("NYI");
                 },
                 getCurrentDirectory: () => "/",
+                getDirectories: () => [],
                 getCanonicalFileName: f => f.toLowerCase(),
                 getNewLine: () => "\r\n",
                 useCaseSensitiveFileNames: () => false,
diff --git a/tests/cases/unittests/reuseProgramStructure.ts b/tests/cases/unittests/reuseProgramStructure.ts
index 6ab90595f9f70..154cfdd702f8e 100644
--- a/tests/cases/unittests/reuseProgramStructure.ts
+++ b/tests/cases/unittests/reuseProgramStructure.ts
@@ -117,6 +117,9 @@ namespace ts {
             getCurrentDirectory(): string {
                 return "";
             },
+            getDirectories(path: string): string[] {
+                return [];
+            },
             getCanonicalFileName(fileName): string {
                 return sys && sys.useCaseSensitiveFileNames ? fileName : fileName.toLowerCase();
             },
@@ -336,7 +339,7 @@ namespace ts {
                 { name: "/a.ts", text: SourceText.New("/// <reference types='typedefs'/>", "", "var x = $") },
                 { name: "/types/typedefs/index.d.ts", text: SourceText.New("", "", "declare var $: number") },
             ];
-            const options: CompilerOptions = { target, typesRoot: "/" };
+            const options: CompilerOptions = { target, typeRoots: ["/types"] };
 
             const program_1 = newProgram(files, ["/a.ts"], options);
             checkResolvedTypeDirectivesCache(program_1, "/a.ts", { "typedefs": { resolvedFileName: "/types/typedefs/index.d.ts", primary: true } });

From e8ac1abbd6b3b1b720e39190b74252c76edab043 Mon Sep 17 00:00:00 2001
From: Ryan Cavanaugh <RyanCavanaugh@users.noreply.github.com>
Date: Mon, 13 Jun 2016 09:33:49 -0700
Subject: [PATCH 2/7] Baseline fix, CR comments, lint

---
 src/compiler/commandLineParser.ts             |  5 ++--
 src/compiler/program.ts                       |  4 +--
 src/compiler/types.ts                         |  2 +-
 src/server/editorServices.ts                  |  2 +-
 src/services/services.ts                      |  2 +-
 .../reference/library-reference-6.symbols     | 16 ++++++++++
 .../reference/library-reference-6.trace.json  | 30 +++++--------------
 .../reference/library-reference-6.types       | 16 ++++++++++
 .../moduleResolutionWithExtensions.trace.json |  4 +++
 9 files changed, 51 insertions(+), 30 deletions(-)
 create mode 100644 tests/baselines/reference/library-reference-6.symbols
 create mode 100644 tests/baselines/reference/library-reference-6.types

diff --git a/src/compiler/commandLineParser.ts b/src/compiler/commandLineParser.ts
index 74bfdf3e96178..9e9fb8e2ee20c 100644
--- a/src/compiler/commandLineParser.ts
+++ b/src/compiler/commandLineParser.ts
@@ -341,8 +341,9 @@ namespace ts {
             type: "list",
             element: {
                 name: "typeRoots",
-                type: "string"
-            }            
+                type: "string",
+                isFilePath: true
+            }
         },
         {
             name: "types",
diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index f6cc048ace660..9cb000a4d615a 100644
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -217,9 +217,9 @@ namespace ts {
         // Check primary library paths
         if (typeRoots.length) {
             if (traceEnabled) {
-                trace(host, Diagnostics.Resolving_with_primary_search_path_0, typeRoots.join(', '));
+                trace(host, Diagnostics.Resolving_with_primary_search_path_0, typeRoots.join(", "));
             }
-            const primarySearchPaths = options.typeRoots || defaultTypeRoots;
+            const primarySearchPaths = typeRoots;
             for (const typeRoot of primarySearchPaths) {
                 const candidate = combinePaths(typeRoot, typeReferenceDirectiveName);
                 const candidateDirectory = getDirectoryPath(candidate);
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index d9edd5a76c420..db34bb7c6e861 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -2562,7 +2562,7 @@ namespace ts {
         target?: ScriptTarget;
         traceResolution?: boolean;
         types?: string[];
-        // Paths used to used to compute primary types search locations
+        /** Paths used to used to compute primary types search locations */
         typeRoots?: string[];
         typesSearchPaths?: string[];
         /*@internal*/ version?: boolean;
diff --git a/src/server/editorServices.ts b/src/server/editorServices.ts
index 53b0c28671f68..b887b5c725668 100644
--- a/src/server/editorServices.ts
+++ b/src/server/editorServices.ts
@@ -316,7 +316,7 @@ namespace ts.server {
         }
 
         getDirectories(path: string): string[] {
-            return this.host.getDirectories ? this.host.getDirectories(path) : [];
+            return this.host.getDirectories(path);
         }
 
         /**
diff --git a/src/services/services.ts b/src/services/services.ts
index 6d29310f93c52..ba157afaf9f18 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -2141,7 +2141,7 @@ namespace ts {
         const getCanonicalFileName = createGetCanonicalFileName(!!useCaseSensitiveFileNames);
 
         function getKeyForCompilationSettings(settings: CompilerOptions): DocumentRegistryBucketKey {
-            return <DocumentRegistryBucketKey>`_${settings.target}|${settings.module}|${settings.noResolve}|${settings.jsx}|${settings.allowJs}|${settings.baseUrl}|${settings.typeRoots}|${JSON.stringify(settings.rootDirs)}|${JSON.stringify(settings.paths)}`;
+            return <DocumentRegistryBucketKey>`_${settings.target}|${settings.module}|${settings.noResolve}|${settings.jsx}|${settings.allowJs}|${settings.baseUrl}|${JSON.stringify(settings.typeRoots)}|${JSON.stringify(settings.rootDirs)}|${JSON.stringify(settings.paths)}`;
         }
 
         function getBucketForCompilationSettings(key: DocumentRegistryBucketKey, createIfMissing: boolean): FileMap<DocumentRegistryEntry> {
diff --git a/tests/baselines/reference/library-reference-6.symbols b/tests/baselines/reference/library-reference-6.symbols
new file mode 100644
index 0000000000000..595d43df3faec
--- /dev/null
+++ b/tests/baselines/reference/library-reference-6.symbols
@@ -0,0 +1,16 @@
+=== /src/foo.ts ===
+/// <reference types="alpha" />
+var x: string = alpha.a;
+>x : Symbol(x, Decl(foo.ts, 1, 3))
+>alpha.a : Symbol(a, Decl(index.d.ts, 3, 20))
+>alpha : Symbol(alpha, Decl(index.d.ts, 3, 11))
+>a : Symbol(a, Decl(index.d.ts, 3, 20))
+
+=== /node_modules/@types/alpha/index.d.ts ===
+
+// The primary lookup folder is relative to tsconfig.json, if present
+
+declare var alpha: { a: string };
+>alpha : Symbol(alpha, Decl(index.d.ts, 3, 11))
+>a : Symbol(a, Decl(index.d.ts, 3, 20))
+
diff --git a/tests/baselines/reference/library-reference-6.trace.json b/tests/baselines/reference/library-reference-6.trace.json
index fc29f3f2478b8..21843c2ecf414 100644
--- a/tests/baselines/reference/library-reference-6.trace.json
+++ b/tests/baselines/reference/library-reference-6.trace.json
@@ -2,27 +2,11 @@
     "======== Resolving type reference directive 'alpha', containing file '/src/foo.ts', root directory 'node_modules/@types'. ========",
     "Resolving with primary search path 'node_modules/@types'",
     "File 'node_modules/@types/alpha/package.json' does not exist.",
-    "File 'node_modules/@types/alpha/index.d.ts' does not exist.",
-    "Looking up in 'node_modules' folder, initial location '/src'",
-    "File '/src/node_modules/alpha.ts' does not exist.",
-    "File '/src/node_modules/alpha.d.ts' does not exist.",
-    "File '/src/node_modules/alpha/package.json' does not exist.",
-    "File '/src/node_modules/alpha/index.ts' does not exist.",
-    "File '/src/node_modules/alpha/index.d.ts' does not exist.",
-    "File '/src/node_modules/@types/alpha.ts' does not exist.",
-    "File '/src/node_modules/@types/alpha.d.ts' does not exist.",
-    "File '/src/node_modules/@types/alpha/package.json' does not exist.",
-    "File '/src/node_modules/@types/alpha/index.ts' does not exist.",
-    "File '/src/node_modules/@types/alpha/index.d.ts' does not exist.",
-    "File '/node_modules/alpha.ts' does not exist.",
-    "File '/node_modules/alpha.d.ts' does not exist.",
-    "File '/node_modules/alpha/package.json' does not exist.",
-    "File '/node_modules/alpha/index.ts' does not exist.",
-    "File '/node_modules/alpha/index.d.ts' does not exist.",
-    "File '/node_modules/@types/alpha.ts' does not exist.",
-    "File '/node_modules/@types/alpha.d.ts' does not exist.",
-    "File '/node_modules/@types/alpha/package.json' does not exist.",
-    "File '/node_modules/@types/alpha/index.ts' does not exist.",
-    "File '/node_modules/@types/alpha/index.d.ts' does not exist.",
-    "======== Type reference directive 'alpha' was not resolved. ========"
+    "File 'node_modules/@types/alpha/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'alpha' was successfully resolved to 'node_modules/@types/alpha/index.d.ts', primary: true. ========",
+    "======== Resolving type reference directive 'alpha', containing file '/src/__inferred type names__.ts', root directory 'node_modules/@types'. ========",
+    "Resolving with primary search path 'node_modules/@types'",
+    "File 'node_modules/@types/alpha/package.json' does not exist.",
+    "File 'node_modules/@types/alpha/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'alpha' was successfully resolved to 'node_modules/@types/alpha/index.d.ts', primary: true. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/library-reference-6.types b/tests/baselines/reference/library-reference-6.types
new file mode 100644
index 0000000000000..e2762c0943a9b
--- /dev/null
+++ b/tests/baselines/reference/library-reference-6.types
@@ -0,0 +1,16 @@
+=== /src/foo.ts ===
+/// <reference types="alpha" />
+var x: string = alpha.a;
+>x : string
+>alpha.a : string
+>alpha : { a: string; }
+>a : string
+
+=== /node_modules/@types/alpha/index.d.ts ===
+
+// The primary lookup folder is relative to tsconfig.json, if present
+
+declare var alpha: { a: string };
+>alpha : { a: string; }
+>a : string
+
diff --git a/tests/baselines/reference/moduleResolutionWithExtensions.trace.json b/tests/baselines/reference/moduleResolutionWithExtensions.trace.json
index 6e6589d7c1f8a..7dc9e8c104b8c 100644
--- a/tests/baselines/reference/moduleResolutionWithExtensions.trace.json
+++ b/tests/baselines/reference/moduleResolutionWithExtensions.trace.json
@@ -3,11 +3,13 @@
     "Module resolution kind is not specified, using 'NodeJs'.",
     "Loading module as file / folder, candidate module location '/src/a'.",
     "File '/src/a.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/src/a.ts', result '/src/a.ts'",
     "======== Module name './a' was successfully resolved to '/src/a.ts'. ========",
     "======== Resolving module './a.ts' from '/src/c.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
     "Loading module as file / folder, candidate module location '/src/a.ts'.",
     "File '/src/a.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/src/a.ts', result '/src/a.ts'",
     "======== Module name './a.ts' was successfully resolved to '/src/a.ts'. ========",
     "======== Resolving module './a.js' from '/src/d.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
@@ -17,6 +19,7 @@
     "File '/src/a.js.d.ts' does not exist.",
     "File name '/src/a.js' has a '.js' extension - stripping it",
     "File '/src/a.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/src/a.ts', result '/src/a.ts'",
     "======== Module name './a.js' was successfully resolved to '/src/a.ts'. ========",
     "======== Resolving module './jquery.js' from '/src/jquery_user_1.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
@@ -28,5 +31,6 @@
     "File '/src/jquery.ts' does not exist.",
     "File '/src/jquery.tsx' does not exist.",
     "File '/src/jquery.d.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/src/jquery.d.ts', result '/src/jquery.d.ts'",
     "======== Module name './jquery.js' was successfully resolved to '/src/jquery.d.ts'. ========"
 ]
\ No newline at end of file

From 6702e651a3e6de28a9a751d2c4282494412a0081 Mon Sep 17 00:00:00 2001
From: Ryan Cavanaugh <RyanCavanaugh@users.noreply.github.com>
Date: Mon, 13 Jun 2016 10:15:29 -0700
Subject: [PATCH 3/7] CR changes

---
 src/compiler/program.ts                          |  4 +++-
 .../reference/typingsLookup1.trace.json          | 16 ++++++++++++++++
 .../references/library-reference-6.ts            |  3 ---
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index 9cb000a4d615a..59ae0d862ad9f 100644
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -1031,7 +1031,9 @@ namespace ts {
         // Walk the primary type lookup locations
         let result: string[] = [];
         if (host.directoryExists && host.getDirectories) {
-            for (const root of options.typeRoots || defaultTypeRoots) {
+            const typeRoots = options.typeRoots ||
+                defaultTypeRoots.map(d => combinePaths(options.configFilePath ? getDirectoryPath(options.configFilePath) : host.getCurrentDirectory(), d));
+            for (const root of typeRoots) {
                 if (host.directoryExists(root)) {
                     result = result.concat(host.getDirectories(root));
                 }
diff --git a/tests/baselines/reference/typingsLookup1.trace.json b/tests/baselines/reference/typingsLookup1.trace.json
index 0463c920bd323..ad0354157c381 100644
--- a/tests/baselines/reference/typingsLookup1.trace.json
+++ b/tests/baselines/reference/typingsLookup1.trace.json
@@ -14,5 +14,21 @@
     "File '/node_modules/@types/jquery/package.json' does not exist.",
     "File '/node_modules/@types/jquery/index.ts' does not exist.",
     "File '/node_modules/@types/jquery/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'jquery' was successfully resolved to '/node_modules/@types/jquery/index.d.ts', primary: false. ========",
+    "======== Resolving type reference directive 'jquery', containing file '/__inferred type names__.ts', root directory 'node_modules/@types'. ========",
+    "Resolving with primary search path 'node_modules/@types'",
+    "File 'node_modules/@types/jquery/package.json' does not exist.",
+    "File 'node_modules/@types/jquery/index.d.ts' does not exist.",
+    "Looking up in 'node_modules' folder, initial location '/'",
+    "File '/node_modules/jquery.ts' does not exist.",
+    "File '/node_modules/jquery.d.ts' does not exist.",
+    "File '/node_modules/jquery/package.json' does not exist.",
+    "File '/node_modules/jquery/index.ts' does not exist.",
+    "File '/node_modules/jquery/index.d.ts' does not exist.",
+    "File '/node_modules/@types/jquery.ts' does not exist.",
+    "File '/node_modules/@types/jquery.d.ts' does not exist.",
+    "File '/node_modules/@types/jquery/package.json' does not exist.",
+    "File '/node_modules/@types/jquery/index.ts' does not exist.",
+    "File '/node_modules/@types/jquery/index.d.ts' exist - use it as a name resolution result.",
     "======== Type reference directive 'jquery' was successfully resolved to '/node_modules/@types/jquery/index.d.ts', primary: false. ========"
 ]
\ No newline at end of file
diff --git a/tests/cases/conformance/references/library-reference-6.ts b/tests/cases/conformance/references/library-reference-6.ts
index 765a6760aa49d..13ad382e63654 100644
--- a/tests/cases/conformance/references/library-reference-6.ts
+++ b/tests/cases/conformance/references/library-reference-6.ts
@@ -13,7 +13,4 @@ var x: string = alpha.a;
 
 // @filename: /tsconfig.json
 {
-	"compilerOptions": {
-		"typesRoot": "types"
-	}
 }

From b10d93291fb6b3a7087bff1e93b39ccbb6b4099a Mon Sep 17 00:00:00 2001
From: Ryan Cavanaugh <RyanCavanaugh@users.noreply.github.com>
Date: Mon, 13 Jun 2016 14:20:31 -0700
Subject: [PATCH 4/7] Absolute-ify paths in both places

---
 src/compiler/program.ts                       |  3 +-
 .../reference/library-reference-11.trace.json |  8 ++---
 .../reference/library-reference-12.trace.json |  8 ++---
 .../reference/library-reference-3.trace.json  |  8 ++---
 .../reference/library-reference-6.trace.json  | 20 +++++------
 .../reference/library-reference-7.trace.json  |  8 ++---
 .../reference/typingsLookup1.trace.json       | 34 ++++---------------
 7 files changed, 34 insertions(+), 55 deletions(-)

diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index 59ae0d862ad9f..28dd6275143a9 100644
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -192,7 +192,8 @@ namespace ts {
             traceEnabled
         };
 
-        const typeRoots = options.typeRoots || defaultTypeRoots;
+        const typeRoots = options.typeRoots ||
+            defaultTypeRoots.map(d => combinePaths(options.configFilePath ? getDirectoryPath(options.configFilePath) : host.getCurrentDirectory(), d));
         if (traceEnabled) {
             if (containingFile === undefined) {
                 if (typeRoots === undefined) {
diff --git a/tests/baselines/reference/library-reference-11.trace.json b/tests/baselines/reference/library-reference-11.trace.json
index 7f6a32a0b238f..365fe3ce72d2c 100644
--- a/tests/baselines/reference/library-reference-11.trace.json
+++ b/tests/baselines/reference/library-reference-11.trace.json
@@ -1,8 +1,8 @@
 [
-    "======== Resolving type reference directive 'jquery', containing file '/a/b/consumer.ts', root directory 'node_modules/@types'. ========",
-    "Resolving with primary search path 'node_modules/@types'",
-    "File 'node_modules/@types/jquery/package.json' does not exist.",
-    "File 'node_modules/@types/jquery/index.d.ts' does not exist.",
+    "======== Resolving type reference directive 'jquery', containing file '/a/b/consumer.ts', root directory '/node_modules/@types'. ========",
+    "Resolving with primary search path '/node_modules/@types'",
+    "File '/node_modules/@types/jquery/package.json' does not exist.",
+    "File '/node_modules/@types/jquery/index.d.ts' does not exist.",
     "Looking up in 'node_modules' folder, initial location '/a/b'",
     "File '/a/b/node_modules/jquery.ts' does not exist.",
     "File '/a/b/node_modules/jquery.d.ts' does not exist.",
diff --git a/tests/baselines/reference/library-reference-12.trace.json b/tests/baselines/reference/library-reference-12.trace.json
index b3debaec9d6dd..84144f82729c6 100644
--- a/tests/baselines/reference/library-reference-12.trace.json
+++ b/tests/baselines/reference/library-reference-12.trace.json
@@ -1,8 +1,8 @@
 [
-    "======== Resolving type reference directive 'jquery', containing file '/a/b/consumer.ts', root directory 'node_modules/@types'. ========",
-    "Resolving with primary search path 'node_modules/@types'",
-    "File 'node_modules/@types/jquery/package.json' does not exist.",
-    "File 'node_modules/@types/jquery/index.d.ts' does not exist.",
+    "======== Resolving type reference directive 'jquery', containing file '/a/b/consumer.ts', root directory '/node_modules/@types'. ========",
+    "Resolving with primary search path '/node_modules/@types'",
+    "File '/node_modules/@types/jquery/package.json' does not exist.",
+    "File '/node_modules/@types/jquery/index.d.ts' does not exist.",
     "Looking up in 'node_modules' folder, initial location '/a/b'",
     "File '/a/b/node_modules/jquery.ts' does not exist.",
     "File '/a/b/node_modules/jquery.d.ts' does not exist.",
diff --git a/tests/baselines/reference/library-reference-3.trace.json b/tests/baselines/reference/library-reference-3.trace.json
index 909e42140c850..730835c65e9ac 100644
--- a/tests/baselines/reference/library-reference-3.trace.json
+++ b/tests/baselines/reference/library-reference-3.trace.json
@@ -1,8 +1,8 @@
 [
-    "======== Resolving type reference directive 'jquery', containing file '/src/consumer.ts', root directory 'node_modules/@types'. ========",
-    "Resolving with primary search path 'node_modules/@types'",
-    "File 'node_modules/@types/jquery/package.json' does not exist.",
-    "File 'node_modules/@types/jquery/index.d.ts' does not exist.",
+    "======== Resolving type reference directive 'jquery', containing file '/src/consumer.ts', root directory '/src/node_modules/@types'. ========",
+    "Resolving with primary search path '/src/node_modules/@types'",
+    "File '/src/node_modules/@types/jquery/package.json' does not exist.",
+    "File '/src/node_modules/@types/jquery/index.d.ts' does not exist.",
     "Looking up in 'node_modules' folder, initial location '/src'",
     "File '/src/node_modules/jquery.ts' does not exist.",
     "File '/src/node_modules/jquery.d.ts' does not exist.",
diff --git a/tests/baselines/reference/library-reference-6.trace.json b/tests/baselines/reference/library-reference-6.trace.json
index 21843c2ecf414..48fb49e6c7fb9 100644
--- a/tests/baselines/reference/library-reference-6.trace.json
+++ b/tests/baselines/reference/library-reference-6.trace.json
@@ -1,12 +1,12 @@
 [
-    "======== Resolving type reference directive 'alpha', containing file '/src/foo.ts', root directory 'node_modules/@types'. ========",
-    "Resolving with primary search path 'node_modules/@types'",
-    "File 'node_modules/@types/alpha/package.json' does not exist.",
-    "File 'node_modules/@types/alpha/index.d.ts' exist - use it as a name resolution result.",
-    "======== Type reference directive 'alpha' was successfully resolved to 'node_modules/@types/alpha/index.d.ts', primary: true. ========",
-    "======== Resolving type reference directive 'alpha', containing file '/src/__inferred type names__.ts', root directory 'node_modules/@types'. ========",
-    "Resolving with primary search path 'node_modules/@types'",
-    "File 'node_modules/@types/alpha/package.json' does not exist.",
-    "File 'node_modules/@types/alpha/index.d.ts' exist - use it as a name resolution result.",
-    "======== Type reference directive 'alpha' was successfully resolved to 'node_modules/@types/alpha/index.d.ts', primary: true. ========"
+    "======== Resolving type reference directive 'alpha', containing file '/src/foo.ts', root directory '/node_modules/@types'. ========",
+    "Resolving with primary search path '/node_modules/@types'",
+    "File '/node_modules/@types/alpha/package.json' does not exist.",
+    "File '/node_modules/@types/alpha/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'alpha' was successfully resolved to '/node_modules/@types/alpha/index.d.ts', primary: true. ========",
+    "======== Resolving type reference directive 'alpha', containing file '/src/__inferred type names__.ts', root directory '/node_modules/@types'. ========",
+    "Resolving with primary search path '/node_modules/@types'",
+    "File '/node_modules/@types/alpha/package.json' does not exist.",
+    "File '/node_modules/@types/alpha/index.d.ts' exist - use it as a name resolution result.",
+    "======== Type reference directive 'alpha' was successfully resolved to '/node_modules/@types/alpha/index.d.ts', primary: true. ========"
 ]
\ No newline at end of file
diff --git a/tests/baselines/reference/library-reference-7.trace.json b/tests/baselines/reference/library-reference-7.trace.json
index 909e42140c850..b681ea312a8bb 100644
--- a/tests/baselines/reference/library-reference-7.trace.json
+++ b/tests/baselines/reference/library-reference-7.trace.json
@@ -1,8 +1,8 @@
 [
-    "======== Resolving type reference directive 'jquery', containing file '/src/consumer.ts', root directory 'node_modules/@types'. ========",
-    "Resolving with primary search path 'node_modules/@types'",
-    "File 'node_modules/@types/jquery/package.json' does not exist.",
-    "File 'node_modules/@types/jquery/index.d.ts' does not exist.",
+    "======== Resolving type reference directive 'jquery', containing file '/src/consumer.ts', root directory '/node_modules/@types'. ========",
+    "Resolving with primary search path '/node_modules/@types'",
+    "File '/node_modules/@types/jquery/package.json' does not exist.",
+    "File '/node_modules/@types/jquery/index.d.ts' does not exist.",
     "Looking up in 'node_modules' folder, initial location '/src'",
     "File '/src/node_modules/jquery.ts' does not exist.",
     "File '/src/node_modules/jquery.d.ts' does not exist.",
diff --git a/tests/baselines/reference/typingsLookup1.trace.json b/tests/baselines/reference/typingsLookup1.trace.json
index ad0354157c381..83b0e91d6c7c1 100644
--- a/tests/baselines/reference/typingsLookup1.trace.json
+++ b/tests/baselines/reference/typingsLookup1.trace.json
@@ -1,34 +1,12 @@
 [
-    "======== Resolving type reference directive 'jquery', containing file '/a.ts', root directory 'node_modules/@types'. ========",
-    "Resolving with primary search path 'node_modules/@types'",
-    "File 'node_modules/@types/jquery/package.json' does not exist.",
-    "File 'node_modules/@types/jquery/index.d.ts' does not exist.",
-    "Looking up in 'node_modules' folder, initial location '/'",
-    "File '/node_modules/jquery.ts' does not exist.",
-    "File '/node_modules/jquery.d.ts' does not exist.",
-    "File '/node_modules/jquery/package.json' does not exist.",
-    "File '/node_modules/jquery/index.ts' does not exist.",
-    "File '/node_modules/jquery/index.d.ts' does not exist.",
-    "File '/node_modules/@types/jquery.ts' does not exist.",
-    "File '/node_modules/@types/jquery.d.ts' does not exist.",
+    "======== Resolving type reference directive 'jquery', containing file '/a.ts', root directory '/node_modules/@types'. ========",
+    "Resolving with primary search path '/node_modules/@types'",
     "File '/node_modules/@types/jquery/package.json' does not exist.",
-    "File '/node_modules/@types/jquery/index.ts' does not exist.",
     "File '/node_modules/@types/jquery/index.d.ts' exist - use it as a name resolution result.",
-    "======== Type reference directive 'jquery' was successfully resolved to '/node_modules/@types/jquery/index.d.ts', primary: false. ========",
-    "======== Resolving type reference directive 'jquery', containing file '/__inferred type names__.ts', root directory 'node_modules/@types'. ========",
-    "Resolving with primary search path 'node_modules/@types'",
-    "File 'node_modules/@types/jquery/package.json' does not exist.",
-    "File 'node_modules/@types/jquery/index.d.ts' does not exist.",
-    "Looking up in 'node_modules' folder, initial location '/'",
-    "File '/node_modules/jquery.ts' does not exist.",
-    "File '/node_modules/jquery.d.ts' does not exist.",
-    "File '/node_modules/jquery/package.json' does not exist.",
-    "File '/node_modules/jquery/index.ts' does not exist.",
-    "File '/node_modules/jquery/index.d.ts' does not exist.",
-    "File '/node_modules/@types/jquery.ts' does not exist.",
-    "File '/node_modules/@types/jquery.d.ts' does not exist.",
+    "======== Type reference directive 'jquery' was successfully resolved to '/node_modules/@types/jquery/index.d.ts', primary: true. ========",
+    "======== Resolving type reference directive 'jquery', containing file '/__inferred type names__.ts', root directory '/node_modules/@types'. ========",
+    "Resolving with primary search path '/node_modules/@types'",
     "File '/node_modules/@types/jquery/package.json' does not exist.",
-    "File '/node_modules/@types/jquery/index.ts' does not exist.",
     "File '/node_modules/@types/jquery/index.d.ts' exist - use it as a name resolution result.",
-    "======== Type reference directive 'jquery' was successfully resolved to '/node_modules/@types/jquery/index.d.ts', primary: false. ========"
+    "======== Type reference directive 'jquery' was successfully resolved to '/node_modules/@types/jquery/index.d.ts', primary: true. ========"
 ]
\ No newline at end of file

From 29f52914530e2c632cb3cd5bea9dcd8fe8bca327 Mon Sep 17 00:00:00 2001
From: Ryan Cavanaugh <RyanCavanaugh@users.noreply.github.com>
Date: Mon, 13 Jun 2016 14:37:07 -0700
Subject: [PATCH 5/7] Refactor

---
 src/compiler/program.ts | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index 28dd6275143a9..15afbe182656c 100644
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -178,6 +178,11 @@ namespace ts {
 
     const typeReferenceExtensions = [".d.ts"];
 
+    function getEffectiveTypeRoots(options: CompilerOptions, host: ModuleResolutionHost) {
+        return options.typeRoots ||
+            defaultTypeRoots.map(d => combinePaths(options.configFilePath ? getDirectoryPath(options.configFilePath) : host.getCurrentDirectory(), d));
+    }
+
     /**
      * @param {string | undefined} containingFile - file that contains type reference directive, can be undefined if containing file is unknown.
      * This is possible in case if resolution is performed for directives specified via 'types' parameter. In this case initial path for secondary lookups
@@ -192,8 +197,7 @@ namespace ts {
             traceEnabled
         };
 
-        const typeRoots = options.typeRoots ||
-            defaultTypeRoots.map(d => combinePaths(options.configFilePath ? getDirectoryPath(options.configFilePath) : host.getCurrentDirectory(), d));
+        const typeRoots = getEffectiveTypeRoots(options, host);
         if (traceEnabled) {
             if (containingFile === undefined) {
                 if (typeRoots === undefined) {
@@ -1032,8 +1036,7 @@ namespace ts {
         // Walk the primary type lookup locations
         let result: string[] = [];
         if (host.directoryExists && host.getDirectories) {
-            const typeRoots = options.typeRoots ||
-                defaultTypeRoots.map(d => combinePaths(options.configFilePath ? getDirectoryPath(options.configFilePath) : host.getCurrentDirectory(), d));
+            const typeRoots = getEffectiveTypeRoots(options, host);
             for (const root of typeRoots) {
                 if (host.directoryExists(root)) {
                     result = result.concat(host.getDirectories(root));
@@ -1208,7 +1211,7 @@ namespace ts {
                 (oldOptions.rootDir !== options.rootDir) ||
                 (oldOptions.configFilePath !== options.configFilePath) ||
                 (oldOptions.baseUrl !== options.baseUrl) ||
-                (oldOptions.typeRoots !== options.typeRoots) ||
+                !arrayIsEqualTo(oldOptions.typeRoots, oldOptions.typeRoots) ||
                 !arrayIsEqualTo(oldOptions.rootDirs, options.rootDirs) ||
                 !mapIsEqualTo(oldOptions.paths, options.paths)) {
                 return false;

From 236351d4f0b83a943a90e2a9f6e9994fae256ef7 Mon Sep 17 00:00:00 2001
From: Ryan Cavanaugh <RyanCavanaugh@users.noreply.github.com>
Date: Mon, 13 Jun 2016 14:43:19 -0700
Subject: [PATCH 6/7] Add unit test

---
 tests/cases/unittests/reuseProgramStructure.ts | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/tests/cases/unittests/reuseProgramStructure.ts b/tests/cases/unittests/reuseProgramStructure.ts
index 154cfdd702f8e..db67eb2c252dd 100644
--- a/tests/cases/unittests/reuseProgramStructure.ts
+++ b/tests/cases/unittests/reuseProgramStructure.ts
@@ -259,6 +259,22 @@ namespace ts {
             assert.isTrue(!program_1.structureIsReused);
         });
 
+        it("fails if change affects type references", () => {
+            const program_1 = newProgram(files, ["a.ts"], { types: ["a"] });
+            updateProgram(program_1, ["a.ts"], { types: ["b"] }, files => {
+
+            });
+            assert.isTrue(!program_1.structureIsReused);
+        });
+
+        it("succeeds if change doesn't affect type references", () => {
+            const program_1 = newProgram(files, ["a.ts"], { types: ["a"] });
+            updateProgram(program_1, ["a.ts"], { types: ["a"] },afiles => {
+
+            });
+            assert.isTrue(program_1.structureIsReused);
+        });
+
         it("fails if change affects imports", () => {
             const program_1 = newProgram(files, ["a.ts"], { target });
             updateProgram(program_1, ["a.ts"], { target }, files => {

From 90b319fc246d53604f54c9b7d003ab2dfb741ec6 Mon Sep 17 00:00:00 2001
From: Ryan Cavanaugh <RyanCavanaugh@users.noreply.github.com>
Date: Mon, 13 Jun 2016 14:52:41 -0700
Subject: [PATCH 7/7] lint

---
 tests/cases/unittests/reuseProgramStructure.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/cases/unittests/reuseProgramStructure.ts b/tests/cases/unittests/reuseProgramStructure.ts
index db67eb2c252dd..b8a36baf824ad 100644
--- a/tests/cases/unittests/reuseProgramStructure.ts
+++ b/tests/cases/unittests/reuseProgramStructure.ts
@@ -269,7 +269,7 @@ namespace ts {
 
         it("succeeds if change doesn't affect type references", () => {
             const program_1 = newProgram(files, ["a.ts"], { types: ["a"] });
-            updateProgram(program_1, ["a.ts"], { types: ["a"] },afiles => {
+            updateProgram(program_1, ["a.ts"], { types: ["a"] }, files => {
 
             });
             assert.isTrue(program_1.structureIsReused);