develop

.babelrc

@@ -9,16 +9,11 @@
   "presets": [
     ["env", {
       "targets": {
-        "node": 6
+        "node": true
       }
     }]
   ],
   "plugins": [
-    ["babel-plugin-transform-builtin-extend", {
-      "globals": [
-        "Array"
-      ]
-    }],
     "transform-runtime"
   ],
   "only": [

.travis.yml

@@ -37,7 +37,7 @@ jobs:
   fast_finish: true
   include:
     - stage: release
-      node_js: 9
+      node_js: 8
       deploy:
         skip_cleanup: true
         provider: script

package.json

@@ -2,29 +2,38 @@
   "name": "webpack-config",
   "description": "Helps to load, extend and merge webpack configs",
   "main": "dist/index.js",
-  "files": ["dist/", "src/"],
+  "files": [
+    "dist/",
+    "src/"
+  ],
   "scripts": {
     "clean": "rm -rf dist coverage docs",
     "lint": "eslint --ext js,md ./ --cache",
     "build": "babel src --out-dir dist --source-maps",
     "test": "babel-node jasmine.js",
-    "cover":
-      "NODE_ENV=test nyc --reporter=lcov jasmine JASMINE_CONFIG_PATH=jasmine.json",
+    "cover": "NODE_ENV=test nyc --reporter=lcov jasmine JASMINE_CONFIG_PATH=jasmine.json",
     "postcover": "nyc report",
     "codeclimate": "codeclimate-test-reporter < ./coverage/lcov.info",
     "jsdoc": "jsdoc ./src -c ./jsdoc.json"
   },
   "nyc": {
-    "include": ["src/*.js"],
-    "require": ["babel-register"],
+    "include": [
+      "src/*.js"
+    ],
+    "require": [
+      "babel-register"
+    ],
     "sourceMap": false,
     "instrument": false
   },
   "repository": {
     "type": "git",
     "url": "https://github.com/Fitbit/webpack-config.git"
   },
-  "keywords": ["webpack", "webpack-config"],
+  "keywords": [
+    "webpack",
+    "webpack-config"
+  ],
   "author": "Marat Dreizin <[email protected]>",
   "license": "Apache-2.0",
   "bugs": {
@@ -35,7 +44,6 @@
     "babel-cli": "^6.26.0",
     "babel-eslint": "^8.2.3",
     "babel-plugin-istanbul": "^4.1.6",
-    "babel-plugin-transform-builtin-extend": "^1.1.2",
     "babel-plugin-transform-runtime": "^6.23.0",
     "babel-preset-env": "^1.6.1",
     "babel-register": "^6.26.0",
@@ -57,6 +65,6 @@
     "yargs-parser": "^10.0.0"
   },
   "engines": {
-    "node": ">=6.0.0"
+    "node": ">=8.0.0"
   }
 }

src/ConfigCache.js

@@ -4,6 +4,12 @@ import {
 import ConfigStrategyList from './ConfigStrategyList';
 import DEFAULT_RESOLVERS from './ConfigCacheResolvers';
 
+/**
+ * @private
+ * @type {WeakMap}
+ */
+const CACHE = new WeakMap();
+
 /**
  * @private
  * @type {String}
@@ -25,19 +31,17 @@ const VALUE_RESOLVERS = new WeakMap();
 /**
  * Please set `WEBPACK_CONFIG_CACHE` environment variable to `false` to make it non persistent or just use {@link ConfigCache#persistent}
  * @class
- * @extends {Map}
  */
-class ConfigCache extends Map {
+class ConfigCache {
     /**
      * @constructor
      * @param {ConfigEnvironment} environment
      * @param {Function[]} [valueResolvers]
      */
     constructor(environment, valueResolvers = DEFAULT_RESOLVERS) {
-        super();
-
+        CACHE.set(this, new Map());
         ENVIRONMENT.set(this, environment);
-        VALUE_RESOLVERS.set(this, ConfigStrategyList.from(valueResolvers));
+        VALUE_RESOLVERS.set(this, new ConfigStrategyList(valueResolvers));
     }
 
     /**
@@ -55,6 +59,15 @@ class ConfigCache extends Map {
         return this.environment.getOrDefault(PERSISTENT_KEY, true) === true;
     }
 
+    /**
+     * @private
+     * @readonly
+     * @type {Map}
+     */
+    get cache() {
+        return CACHE.get(this);
+    }
+
     /**
      * @example
      * import {
@@ -79,18 +92,19 @@ class ConfigCache extends Map {
     }
 
     /**
-     * @override
+     * @param {String} key
+     * @returns {*}
      */
     get(key) {
         let value;
 
         if (this.persistent) {
-            if (!this.has(key)) {
+            if (!this.cache.has(key)) {
                 value = require(key);
 
-                this.set(key, value);
+                this.cache.set(key, value);
             } else {
-                value = super.get(key);
+                value = this.cache.get(key);
             }
         } else {
             delete require.cache[key];
@@ -100,6 +114,14 @@ class ConfigCache extends Map {
 
         return this.valueResolvers.resolve(value, x => !isUndefined(x));
     }
+    /**
+     * @param {String} key
+     * @param {*} value
+     * @returns {void}
+     */
+    set(key, value) {
+        return this.cache.set(key, value);
+    }
 }
 
 export default ConfigCache;

src/ConfigFactory.js

@@ -3,7 +3,6 @@ import {
     isObject
 } from 'lodash';
 import Config from './Config';
-import ConfigList from './ConfigList';
 import { env } from './ConfigArgv';
 
 /**
@@ -51,7 +50,7 @@ class ConfigFactory {
 
     /**
      * @param {Function|Object|Object[]} value
-     * @returns {Config|ConfigList}
+     * @returns {Config|Config[]}
      */
     createConfig(value) {
         let config;
@@ -61,7 +60,7 @@ class ConfigFactory {
         }
 
         if (Array.isArray(value)) {
-            config = ConfigList.from(value, x => this.initWith(x));
+            config = Array.from(value, x => this.initWith(x));
         } else if (isObject(value)) {
             config = this.initWith(value);
         }

src/ConfigLoader.js

@@ -62,7 +62,7 @@ class ConfigLoader {
 
     /**
      * @param {String} filename
-     * @returns {Config|ConfigList}
+     * @returns {Config|Config[]}
      */
     loadConfig(filename) {
         filename = this.pathResolver.resolve(filename);

src/ConfigPathResolver.js

@@ -27,7 +27,7 @@ class ConfigPathResolver {
      */
     constructor(stringResolver, pathResolvers = DEFAULT_RESOLVERS) {
         STRING_RESOLVER.set(this, stringResolver);
-        PATH_RESOLVERS.set(this, ConfigStrategyList.from(pathResolvers));
+        PATH_RESOLVERS.set(this, new ConfigStrategyList(pathResolvers));
     }
 
     /**

src/ConfigStrategyList.js

@@ -2,18 +2,39 @@ import {
     isError
 } from 'lodash';
 
+/**
+ * @private
+ * @type {WeakMap}
+ */
+const RESOLVERS = new WeakMap();
+
 /**
  * @class
- * @extends {Array}
  */
-class ConfigStrategyList extends Array {
+class ConfigStrategyList {
+    /**
+     * @constructor
+     * @param {Function[]} resolvers
+     */
+    constructor(resolvers) {
+        RESOLVERS.set(this, resolvers);
+    }
+
+    /**
+     * @readonly
+     * @type {Function[]}
+     */
+    get resolvers() {
+        return RESOLVERS.get(this);
+    }
+
     /**
      * @param {*} value
      * @param {Function} predicate
      * @returns {*}
      */
     resolve(value, predicate) {
-        for (const resolver of this) {
+        for (const resolver of this.resolvers) {
             try {
                 const resolvedValue = resolver(value),
                     throwsError = isError(resolvedValue) || resolvedValue instanceof Error;

test/ConfigFactory.spec.js

@@ -1,5 +1,4 @@
 import Config from '../src/Config';
-import ConfigList from '../src/ConfigList';
 import ConfigFactory from '../src/ConfigFactory';
 import MockConfigContainer from './MockConfigContainer';
 
@@ -42,7 +41,7 @@ describe('ConfigFactory', () => {
                 foo: 'foo1'
             }]);
 
-            expect(configs).toEqual(jasmine.any(ConfigList));
+            expect(configs).toEqual(jasmine.any(Array));
             expect(configs.length).toEqual(1);
             expect(configs[0]).toEqual(jasmine.any(Config));
             expect(configs[0].toObject()).toEqual({

yarn.lock

@@ -647,13 +647,6 @@ babel-plugin-transform-async-to-generator@^6.22.0:
     babel-plugin-syntax-async-functions "^6.8.0"
     babel-runtime "^6.22.0"
 
-babel-plugin-transform-builtin-extend@^1.1.2:
-  version "1.1.2"
-  resolved "https://registry.yarnpkg.com/babel-plugin-transform-builtin-extend/-/babel-plugin-transform-builtin-extend-1.1.2.tgz#5e96fecf58b8fa1ed74efcad88475b2af3c9116e"
-  dependencies:
-    babel-runtime "^6.2.0"
-    babel-template "^6.3.0"
-
 babel-plugin-transform-es2015-arrow-functions@^6.22.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-arrow-functions/-/babel-plugin-transform-es2015-arrow-functions-6.22.0.tgz#452692cb711d5f79dc7f85e440ce41b9f244d221"
@@ -928,7 +921,7 @@ babel-register@^6.26.0:
     mkdirp "^0.5.1"
     source-map-support "^0.4.15"
 
-babel-runtime@^6.18.0, babel-runtime@^6.2.0, babel-runtime@^6.22.0:
+babel-runtime@^6.18.0, babel-runtime@^6.22.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-runtime/-/babel-runtime-6.22.0.tgz#1cf8b4ac67c77a4ddb0db2ae1f74de52ac4ca611"
   dependencies:
@@ -942,7 +935,7 @@ babel-runtime@^6.26.0:
     core-js "^2.4.0"
     regenerator-runtime "^0.11.0"
 
-babel-template@^6.16.0, babel-template@^6.22.0, babel-template@^6.3.0:
+babel-template@^6.16.0, babel-template@^6.22.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-template/-/babel-template-6.22.0.tgz#403d110905a4626b317a2a1fcb8f3b73204b2edb"
   dependencies: