SelectionSet Codegen __typename fix - Closes #2955

.gitignore

@@ -70,3 +70,6 @@ SwiftScripts/.build-**
 # Local generated packages we don't need in the main project
 Sources/AnimalKingdomAPI/Generated/Package.swift
 Sources/AnimalKingdomAPI/Generated/Package.resolved
+
+# Generated js files we don't need committed
+Sources/ApolloCodegenLib/Frontend/dist/

Sources/ApolloCodegenLib/Frontend/CompilationResult.swift

@@ -5,6 +5,8 @@ public class CompilationResult: JavaScriptObject {
   private enum Constants {
     static let LocalCacheMutationDirectiveName = "apollo_client_ios_localCacheMutation"
   }
+  lazy var rootTypes: RootTypeDefinition = self["rootTypes"]
+
   lazy var referencedTypes: [GraphQLNamedType] = self["referencedTypes"]
 
   lazy var operations: [OperationDefinition] = self["operations"]
@@ -13,6 +15,14 @@ public class CompilationResult: JavaScriptObject {
 
   lazy var schemaDocumentation: String? = self["schemaDocumentation"]
 
+  public class RootTypeDefinition: JavaScriptObject {
+    lazy var queryType: GraphQLNamedType = self["queryType"]
+
+    lazy var mutationType: GraphQLNamedType? = self["mutationType"]
+
+    lazy var subscriptionType: GraphQLNamedType? = self["subscriptionType"]
+  }
+
   public class OperationDefinition: JavaScriptObject, Equatable {
     lazy var name: String = self["name"]
 

Sources/ApolloCodegenLib/Frontend/GraphQLSchema.swift

@@ -113,9 +113,8 @@ public class GraphQLCompositeType: GraphQLNamedType {
     "Type - \(name)"
   }
 
-  var isRootFieldType: Bool {
-    ["Query", "Mutation", "Subscription"].contains(name)
-  }
+  var isRootFieldType: Bool = false
+
 }
 
 protocol GraphQLInterfaceImplementingType: GraphQLCompositeType {

Sources/ApolloCodegenLib/Frontend/JavaScript/src/compiler/index.ts

@@ -46,6 +46,7 @@ function filePathForNode(node: ASTNode): string | undefined {
 }
 
 export interface CompilationResult {
+  rootTypes: ir.RootTypeDefinition;
   operations: ir.OperationDefinition[];
   fragments: ir.FragmentDefinition[];
   referencedTypes: GraphQLNamedType[];
@@ -71,6 +72,17 @@ export function compileToIR(
   const fragmentMap = new Map<String, ir.FragmentDefinition>();
   const referencedTypes = new Set<GraphQLNamedType>();
 
+  const queryType = schema.getQueryType() as GraphQLNamedType;
+  if (queryType === undefined) {
+    throw new GraphQLError("GraphQL Schema must contain a 'query' root type definition.", { });
+  }
+
+  const rootTypes: ir.RootTypeDefinition = {
+    queryType: queryType,
+    mutationType: schema.getMutationType() ?? undefined,
+    subscriptionType: schema.getSubscriptionType() ?? undefined
+  };
+
   for (const definitionNode of document.definitions) {
     if (definitionNode.kind !== Kind.OPERATION_DEFINITION) continue;
 
@@ -86,7 +98,8 @@ export function compileToIR(
   }
 
   return {
-    operations,
+    rootTypes: rootTypes,
+    operations: operations,
     fragments: Array.from(fragmentMap.values()),
     referencedTypes: Array.from(referencedTypes.values()),
     schemaDocumentation: schema.description ?? undefined

Sources/ApolloCodegenLib/Frontend/JavaScript/src/compiler/ir.ts

@@ -1,12 +1,19 @@
 import {
   GraphQLCompositeType,
   GraphQLInputType,
+  GraphQLNamedType,
   GraphQLObjectType,
   GraphQLOutputType,
   GraphQLType,
 } from "graphql";
 import { GraphQLValue } from "./values";
 
+export interface RootTypeDefinition {
+  queryType: GraphQLNamedType;
+  mutationType: GraphQLNamedType | undefined;
+  subscriptionType: GraphQLNamedType | undefined;
+}
+
 export interface OperationDefinition {
   name: string;
   operationType: OperationType;

Sources/ApolloCodegenLib/Frontend/auto_rollup.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+output_file="$SCRIPT_DIR/ApolloCodegenFrontendBundle.swift"
+$( cd "$SCRIPT_DIR/Javascript" && rollup -c )
+minJS=$(cat "$SCRIPT_DIR/dist/ApolloCodegenFrontend.bundle.js")
+printf "%s%s%s" "let ApolloCodegenFrontendBundle: String = #\"" "$minJS" "\"#" > $output_file

Sources/ApolloCodegenLib/IR/IR.swift

@@ -17,6 +17,20 @@ class IR {
       referencedTypes: .init(compilationResult.referencedTypes),
       documentation: compilationResult.schemaDocumentation
     )
+    self.processRootTypes()
+  }
+
+  private func processRootTypes() {
+    let rootTypes = compilationResult.rootTypes
+    let typeList = [rootTypes.queryType.name, rootTypes.mutationType?.name, rootTypes.subscriptionType?.name].compactMap { $0 }
+
+    compilationResult.operations.forEach { op in
+      op.rootType.isRootFieldType = typeList.contains(op.rootType.name)
+    }
+
+    compilationResult.fragments.forEach { fragment in
+      fragment.type.isRootFieldType = typeList.contains(fragment.type.name)
+    }
   }
 
   /// A top level GraphQL definition, which can be an operation or a named fragment.

Tests/ApolloCodegenInternalTestHelpers/MockCompilationResult.swift

@@ -2,8 +2,11 @@
 
 public extension CompilationResult {
 
-  class func mock() -> Self {
+  class func mock(
+    rootTypes: RootTypeDefinition = RootTypeDefinition.mock()
+  ) -> Self {
     let mock = Self.emptyMockObject()
+    mock.rootTypes = rootTypes
     mock.referencedTypes = []
     mock.fragments = []
     mock.operations = []
@@ -12,6 +15,22 @@ public extension CompilationResult {
 
 }
 
+public extension CompilationResult.RootTypeDefinition {
+
+  class func mock(
+    queryName: String = "Query",
+    mutationName: String = "Mutation",
+    subscriptionName: String = "Subscription"
+  ) -> Self {
+    let mock = Self.emptyMockObject()
+    mock.queryType = GraphQLCompositeType.mock(queryName)
+    mock.mutationType = GraphQLCompositeType.mock(mutationName)
+    mock.subscriptionType = GraphQLCompositeType.mock(subscriptionName)
+    return mock
+  }
+
+}
+
 public extension CompilationResult.OperationDefinition {
 
   class func mock(

Tests/ApolloCodegenInternalTestHelpers/MockGraphQLType.swift

@@ -12,7 +12,6 @@ public extension GraphQLCompositeType {
   }
 }
 
-
 public extension GraphQLObjectType {
   class override func mock(
     _ name: String = ""

Tests/ApolloCodegenTests/CodeGeneration/Templates/SelectionSet/SelectionSetTemplateTests.swift

@@ -336,6 +336,53 @@ class SelectionSetTemplateTests: XCTestCase {
     // then
     expect(actual).to(equalLineByLine(expected, atLine: 6, ignoringExtraLines: true))
   }
+
+  func test__render_selections__givenCustomRootTypes_doesNotGenerateTypenameField() throws {
+    // given
+    schemaSDL = """
+    schema {
+      query: RootQueryType
+      mutation: RootMutationType
+    }
+
+    type RootQueryType {
+      allAnimals: [Animal!]
+    }
+
+    type RootMutationType {
+      feedAnimal: Animal!
+    }
+
+    type Animal {
+      FieldName: String!
+    }
+    """
+
+    document = """
+    query TestOperation {
+      allAnimals {
+        FieldName
+      }
+    }
+    """
+
+    let expected = """
+      public static var __selections: [ApolloAPI.Selection] { [
+        .field("allAnimals", [AllAnimal]?.self),
+      ] }
+    """
+
+    // when
+    try buildSubjectAndOperation()
+    let allAnimals = try XCTUnwrap(
+      operation[field: "query"] as? IR.EntityField
+    )
+
+    let actual = subject.render(field: allAnimals)
+
+    // then
+    expect(actual).to(equalLineByLine(expected, atLine: 7, ignoringExtraLines: true))
+  }
 
   // MARK: Selections - Fields