Merge pull request #245 from stefanpenner/lazily-read-babel-config

lazily access babel config, this ensures all other "writers" have

packages/ember-auto-import/package.json

@@ -18,6 +18,7 @@
   "repository": "https://github.com/ef4/ember-auto-import",
   "scripts": {
     "compile": "tsc",
+    "clean": "git clean -x -f",
     "build": "ember build",
     "lint": "eslint . && tslint --project .",
     "start": "ember serve",

packages/ember-auto-import/ts/package.ts

@@ -23,8 +23,11 @@ export default class Package {
   public name: string;
   public root: string;
   public isAddon: boolean;
-  public babelOptions: any;
-  public babelMajorVersion: number;
+  private _options: any;
+  private _parent: any;
+  private _hasBabelDetails = false;
+  private _babelMajorVersion?: number;
+  private _babelOptions: any;
   private autoImportOptions: Options | undefined;
   private emberCLIBabelExtensions: string[];
   private isAddonCache = new Map<string, boolean>();
@@ -46,25 +49,40 @@ export default class Package {
     this.isDeveloping = !this.isAddon || this.root === appOrAddon.project.root;
 
     // This is the per-package options from ember-cli
-    let options = this.isAddon
+    this._options = this.isAddon
       ? appOrAddon.parent.options
       : appOrAddon.app.options;
+    this._parent = appOrAddon.parent;
 
     // Stash our own config options
-    this.autoImportOptions = options.autoImport;
+    this.autoImportOptions = this._options.autoImport;
 
-    this.emberCLIBabelExtensions = options['ember-cli-babel']
-      && options['ember-cli-babel'].extensions || ['js'];
-
-    let { babelOptions, version } = this.buildBabelOptions(appOrAddon.parent, options);
-
-    this.babelOptions = babelOptions;
-    this.babelMajorVersion = version;
+    this.emberCLIBabelExtensions = this._options['ember-cli-babel']
+      && this._options['ember-cli-babel'].extensions || ['js'];
 
     this.pkgCache = appOrAddon.parent.pkg;
     this.pkgGeneration = pkgGeneration;
   }
 
+  _ensureBabelDetails() {
+    if (this._hasBabelDetails) { return; }
+    let { babelOptions, version } = this.buildBabelOptions(this._parent, this._options);
+
+    this._babelOptions = babelOptions;
+    this._babelMajorVersion = version;
+    this._hasBabelDetails = true;
+  }
+
+  get babelOptions() {
+    this._ensureBabelDetails();
+    return this._babelOptions;
+  }
+
+  get babelMajorVersion() {
+    this._ensureBabelDetails();
+    return this._babelMajorVersion;
+  }
+
   private buildBabelOptions(instance: any, options: any) {
     // Generate the same babel options that the package (meaning app or addon)
     // is using. We will use these so we can configure our parser to

packages/ember-auto-import/ts/tests/analyzer-test.ts

@@ -15,22 +15,37 @@ Qmodule('analyzer', function(hooks) {
   let upstream: string;
   let analyzer: Analyzer;
   let pack: Partial<Package>;
+  let babelOptionsWasAccessed = false;
 
   hooks.beforeEach(function(this: any) {
     quickTemp.makeOrRemake(this, 'workDir', 'auto-import-analyzer-tests');
     ensureDirSync(upstream = join(this.workDir, 'upstream'));
-    pack = { babelOptions: {}, babelMajorVersion: 6, fileExtensions: ['js'] };
+    pack = {
+      get babelOptions() {
+        babelOptionsWasAccessed = true;
+        return {};
+      },
+      babelMajorVersion: 6,
+      fileExtensions: ['js']
+    };
     analyzer = new Analyzer(new UnwatchedDir(upstream), pack as Package);
     builder = new broccoli.Builder(analyzer);
   });
 
   hooks.afterEach(function(this: any) {
+    babelOptionsWasAccessed = false;
     removeSync(this.workDir);
     if (builder) {
       return builder.cleanup();
     }
   });
 
+  test('babelOptions are accessed only during build', async function(assert) {
+    assert.notOk(babelOptionsWasAccessed);
+    await builder.build();
+    assert.ok(babelOptionsWasAccessed);
+  });
+
   test('initial file passes through', async function(assert) {
     let original = "import 'some-package';";
     outputFileSync(join(upstream, 'sample.js'), original);