feat: layer meta and source options

src/loader.ts

@@ -11,19 +11,33 @@ import { DotenvOptions, setupDotenv } from "./dotenv";
 
 export type UserInputConfig = Record<string, any>;
 
+export interface ConfigLayerMeta {
+  name?: string;
+  [key: string]: any;
+}
+
 export interface C12InputConfig {
-  extends?: string | string[];
   $envName?: string;
   $test?: UserInputConfig;
   $development?: UserInputConfig;
   $production?: UserInputConfig;
   $env?: Record<string, UserInputConfig>;
+  $meta?: ConfigLayerMeta;
 }
 
 export interface InputConfig extends C12InputConfig, UserInputConfig {}
 
+export interface SourceOptions {
+  meta?: ConfigLayerMeta;
+  overrides?: UserInputConfig;
+  [key: string]: any;
+}
+
 export interface ConfigLayer<T extends InputConfig = InputConfig> {
   config: T | null;
+  source?: string;
+  sourceOptions?: SourceOptions;
+  meta?: ConfigLayerMeta;
   cwd?: string;
   configFile?: string;
 }
@@ -215,18 +229,28 @@ async function extendConfig(config, options: LoadConfigOptions) {
     );
     delete config[key];
   }
-  for (const extendSource of extendSources) {
+  for (let extendSource of extendSources) {
+    const originalExtendSource = extendSource;
+    let sourceOptions = {};
+    if (extendSource.source) {
+      sourceOptions = extendSource.options || {};
+      extendSource = extendSource.source;
+    }
+    if (Array.isArray(extendSource)) {
+      sourceOptions = extendSource[1] || {};
+      extendSource = extendSource[0];
+    }
     if (typeof extendSource !== "string") {
       // TODO: Use error in next major versions
       // eslint-disable-next-line no-console
       console.warn(
         `Cannot extend config from \`${JSON.stringify(
-          extendSource
-        )}\` (which should be a string) in ${options.cwd}`
+          originalExtendSource
+        )}\` in ${options.cwd}`
       );
       continue;
     }
-    const _config = await resolveConfig(extendSource, options);
+    const _config = await resolveConfig(extendSource, options, sourceOptions);
     if (!_config.config) {
       // TODO: Use error in next major versions
       // eslint-disable-next-line no-console
@@ -252,7 +276,8 @@ const NPM_PACKAGE_RE =
 
 async function resolveConfig(
   source: string,
-  options: LoadConfigOptions
+  options: LoadConfigOptions,
+  sourceOptions: SourceOptions = {}
 ): Promise<ResolvedConfig> {
   // Custom user resolver
   if (options.resolve) {
@@ -292,7 +317,7 @@ async function resolveConfig(
   if (isDir) {
     source = options.configFile;
   }
-  const res: ResolvedConfig = { config: undefined, cwd };
+  const res: ResolvedConfig = { config: undefined, cwd, source, sourceOptions };
   try {
     res.configFile = options.jiti.resolve(resolve(cwd, source), {
       paths: [cwd],
@@ -316,5 +341,14 @@ async function resolveConfig(
     res.config = defu(envConfig, res.config);
   }
 
+  // Meta
+  res.meta = defu(res.sourceOptions.meta, res.config.$meta);
+  delete res.config.$meta;
+
+  // Overrides
+  if (res.sourceOptions.overrides) {
+    res.config = defu(res.sourceOptions.overrides, res.config);
+  }
+
   return res;
 }

test/fixture/base/config.ts

@@ -1,4 +1,8 @@
 export default {
+  $meta: {
+    name: "base",
+    version: "1.0.0",
+  },
   baseConfig: true,
   colors: {
     primary: "base_primary",

test/fixture/config.ts

@@ -1,6 +1,6 @@
 export default {
   theme: "./theme",
-  extends: ["c12-npm-test"],
+  extends: [["c12-npm-test", { userMeta: 123 }]],
   $test: {
     extends: ["./config.dev"],
     envConfig: true,

test/index.test.ts

@@ -95,7 +95,12 @@ describe("c12", () => {
             "envConfig": true,
             "extends": [
               "./config.dev",
-              "c12-npm-test",
+              [
+                "c12-npm-test",
+                {
+                  "userMeta": 123,
+                },
+              ],
             ],
             "overriden": false,
             "theme": "./theme",
@@ -126,6 +131,9 @@ describe("c12", () => {
           },
           "configFile": "<path>/fixture/theme/config.ts",
           "cwd": "<path>/fixture/theme",
+          "meta": {},
+          "source": "config",
+          "sourceOptions": {},
         },
         {
           "config": {
@@ -146,20 +154,34 @@ describe("c12", () => {
           },
           "configFile": "<path>/fixture/base/config.ts",
           "cwd": "<path>/fixture/base",
+          "meta": {
+            "name": "base",
+            "version": "1.0.0",
+          },
+          "source": "config",
+          "sourceOptions": {},
         },
         {
           "config": {
             "devConfig": true,
           },
           "configFile": "<path>/fixture/config.dev.ts",
           "cwd": "<path>/fixture",
+          "meta": {},
+          "source": "./config.dev",
+          "sourceOptions": {},
         },
         {
           "config": {
             "npmConfig": true,
           },
           "configFile": "<path>/fixture/node_modules/c12-npm-test/config.ts",
           "cwd": "<path>/fixture/node_modules/c12-npm-test",
+          "meta": {},
+          "source": "<path>/fixture/node_modules/c12-npm-test/config.ts",
+          "sourceOptions": {
+            "userMeta": 123,
+          },
         },
         {
           "config": {