build: import tslib instead of letting tsc generate helpers

Author: jelbourn

package.json

@@ -35,6 +35,7 @@
     "core-js": "^2.4.1",
     "rxjs": "^5.0.1",
     "systemjs": "0.19.43",
+    "tslib": "^1.7.1",
     "zone.js": "^0.8.4"
   },
   "devDependencies": {
@@ -104,6 +105,7 @@
     "request": "^2.81.0",
     "resolve-bin": "^0.4.0",
     "rollup": "^0.41.6",
+    "rollup-plugin-node-resolve": "^3.0.0",
     "run-sequence": "^1.2.2",
     "scss-bundle": "^2.0.1-beta.7",
     "selenium-webdriver": "^3.4.0",

src/cdk/package.json

@@ -26,5 +26,8 @@
   "peerDependencies": {
     "@angular/core": "^4.0.0",
     "@angular/common": "^4.0.0"
+  },
+  "dependencies": {
+    "tslib": "^1.7.1"
   }
 }

src/cdk/tsconfig-build.json

@@ -6,6 +6,7 @@
     "declaration": true,
     "stripInternal": false,
     "experimentalDecorators": true,
+    "importHelpers": true,
     "module": "es2015",
     "moduleResolution": "node",
     "outDir": "../../dist/packages/cdk",

src/lib/package.json

@@ -24,5 +24,8 @@
   "peerDependencies": {
     "@angular/core": "^4.0.0",
     "@angular/common": "^4.0.0"
+  },
+  "dependencies": {
+    "tslib": "^1.7.1"
   }
 }

src/lib/tsconfig-build.json

@@ -5,6 +5,7 @@
     "declaration": true,
     "stripInternal": false,
     "experimentalDecorators": true,
+    "importHelpers": true,
     "module": "es2015",
     "moduleResolution": "node",
     "outDir": "../../dist/packages/material",

src/material-examples/package.json

@@ -26,5 +26,8 @@
     "@angular/core": "^4.0.0",
     "@angular/common": "^4.0.0",
     "@angular/http": "^4.0.0"
+  },
+  "dependencies": {
+    "tslib": "^1.7.1"
   }
 }

src/material-examples/tsconfig-build.json

@@ -5,6 +5,7 @@
     "declaration": true,
     "stripInternal": false,
     "experimentalDecorators": true,
+    "importHelpers": true,
     "module": "es2015",
     "moduleResolution": "node",
     "outDir": "../../dist/packages/material-examples",

tools/gulp/packaging/build-bundles.ts

@@ -32,6 +32,7 @@ export async function buildPackageBundles(entryFile: string, packageName: string
 
   // Downlevel FESM-2015 file to ES5.
   transpileFile(fesm2015File, fesm2014File, {
+    importHelpers: true,
     target: ScriptTarget.ES5,
     module: ModuleKind.ES2015,
     allowJs: true

tools/gulp/packaging/rollup-helpers.ts

@@ -2,8 +2,13 @@ import {LICENSE_BANNER} from '../constants';
 
 // There are no type definitions available for these imports.
 const rollup = require('rollup');
+const rollupNodeResolutionPlugin = require('rollup-plugin-node-resolve');
 
 const ROLLUP_GLOBALS = {
+  // Import tslib rather than having TypeScript output its helpers multiple times.
+  // See https://github.com/Microsoft/tslib
+  'tslib': 'tslib',
+
   // Angular dependencies
   '@angular/animations': 'ng.animations',
   '@angular/core': 'ng.core',
@@ -50,10 +55,10 @@ export type BundleConfig = {
 
 /** Creates a rollup bundle of a specified JavaScript file.*/
 export function createRollupBundle(config: BundleConfig): Promise<any> {
-  const bundleOptions = {
+  const bundleOptions: any = {
     context: 'this',
     external: Object.keys(ROLLUP_GLOBALS),
-    entry: config.entry
+    entry: config.entry,
   };
 
   const writeOptions = {
@@ -67,5 +72,19 @@ export function createRollupBundle(config: BundleConfig): Promise<any> {
     sourceMap: true
   };
 
+  // When creating a UMD, we want to exclude tslib from the `external` and `globals` bundle options
+  // so that it is inlined into the bundle.
+  if (config.format === 'umd') {
+    bundleOptions.plugins = [rollupNodeResolutionPlugin()];
+
+    // Clone ROLLUP_GLOBALS so we don't accidentally modify it.
+    bundleOptions.globals = Object.assign({}, ROLLUP_GLOBALS);
+    delete bundleOptions.globals.tslib;
+
+    const external = Object.keys(ROLLUP_GLOBALS);
+    external.splice(external.indexOf('tslib'), 1);
+    bundleOptions.external = external;
+  }
+
   return rollup.rollup(bundleOptions).then((bundle: any) => bundle.write(writeOptions));
 }