feat(@angular-devkit/build-angular): differential loading check

package.json

@@ -82,6 +82,8 @@
     "@bazel/karma": "~0.26.0",
     "@bazel/typescript": "~0.26.0",
     "@ngtools/json-schema": "^1.1.0",
+    "@types/browserslist": "^4.4.0",
+    "@types/caniuse-api": "^3.0.0",
     "@types/copy-webpack-plugin": "^4.4.1",
     "@types/express": "^4.16.0",
     "@types/glob": "^7.0.0",

packages/angular_devkit/build_angular/package.json

@@ -14,6 +14,8 @@
     "@ngtools/webpack": "0.0.0",
     "ajv": "6.10.0",
     "autoprefixer": "9.5.0",
+    "browserslist": "4.5.2",
+    "caniuse-api": "3.0.0",
     "circular-dependency-plugin": "5.0.2",
     "clean-css": "4.2.1",
     "copy-webpack-plugin": "5.0.2",
@@ -83,5 +85,8 @@
     "popper.js": "^1.14.1",
     "protractor": "~5.4.0",
     "zone.js": "^0.9.0"
+  },
+  "peerDependencies": {
+    "typescript": ">=2.7 < 3.4"
   }
 }

packages/angular_devkit/build_angular/src/browser/utils.ts

@@ -0,0 +1,32 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import { Path, getSystemPath } from '@angular-devkit/core';
+import * as browserslist from 'browserslist';
+import * as caniuse from 'caniuse-api';
+import * as ts from 'typescript';
+
+
+export function isDifferentialLoadingNeeded(
+  projectRoot: Path,
+  target: ts.ScriptTarget): boolean {
+
+  const supportES2015 = target !== ts.ScriptTarget.ES3 && target !== ts.ScriptTarget.ES5;
+
+  return supportES2015 && isEs5SupportNeeded(projectRoot);
+}
+
+export function isEs5SupportNeeded(projectRoot: Path): boolean {
+
+  const browsersList: string[] = browserslist(
+    undefined, {
+      path: getSystemPath(projectRoot),
+    });
+
+  return !caniuse.isSupported('es6-module', browsersList.join(', '));
+}

packages/angular_devkit/build_angular/src/browser/utils_spec.ts

@@ -0,0 +1,61 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+
+import { TestProjectHost } from '@angular-devkit/architect/testing';
+import { join, normalize } from '@angular-devkit/core';
+import { ScriptTarget } from 'typescript';
+import {
+  isDifferentialLoadingNeeded,
+} from './utils';
+
+const devkitRoot = (global as any)._DevKitRoot; // tslint:disable-line:no-any
+const workspaceRoot = join(
+  devkitRoot,
+  'tests/angular_devkit/build_angular/hello-world-app/');
+
+const host = new TestProjectHost(normalize(workspaceRoot));
+
+
+describe('differential loading', () => {
+
+  beforeEach(async () => host.initialize().toPromise());
+  afterEach(async () => host.restore().toPromise());
+
+  it('detects the need for differential loading for IE 9-11 and ES2015', () => {
+
+    host.writeMultipleFiles({
+      'browserslist': 'IE 9-11',
+    });
+
+    const needed = isDifferentialLoadingNeeded(host.root(), ScriptTarget.ES2015);
+    expect(needed).toBe(true);
+  });
+
+  it('detects no need for differential loading for Chrome and ES2015', () => {
+
+    host.writeMultipleFiles({
+      'browserslist': 'last 1 chrome version',
+    });
+
+    const needed = isDifferentialLoadingNeeded(host.root(), ScriptTarget.ES2015);
+
+    expect(needed).toBe(false);
+  });
+
+  it('detects no need for differential loading for target is ES5', () => {
+
+    host.writeMultipleFiles({
+      'browserslist': 'last 1 chrome version',
+    });
+
+    const needed = isDifferentialLoadingNeeded(host.root(), ScriptTarget.ES5);
+
+    expect(needed).toBe(false);
+  });
+});

yarn.lock

@@ -253,6 +253,16 @@
     "@types/connect" "*"
     "@types/node" "*"
 
+"@types/browserslist@^4.4.0":
+  version "4.4.0"
+  resolved "https://registry.yarnpkg.com/@types/browserslist/-/browserslist-4.4.0.tgz#e2a5f7f8c7e97afb39f50812a77e5230d3ca2353"
+  integrity sha512-hrIjWSu7Hh96/rKlpChe58qHEwIZ0+F5Zf4QNdvSVP5LUXbaJM04g9tBjo702VTNqPZr5znEJeqNR3nAV3vJPg==
+
+"@types/caniuse-api@^3.0.0":
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/@types/caniuse-api/-/caniuse-api-3.0.0.tgz#af31cc52062be0ab24583be072fd49b634dcc2fe"
+  integrity sha512-wT1VfnScjAftZsvLYaefu/UuwYJdYBwD2JDL2OQd01plGmuAoir5V6HnVHgrfh7zEwcasoiyO2wQ+W58sNh2sw==
+
 "@types/caseless@*":
   version "0.12.1"
   resolved "https://registry.yarnpkg.com/@types/caseless/-/caseless-0.12.1.tgz#9794c69c8385d0192acc471a540d1f8e0d16218a"
@@ -1562,6 +1572,15 @@ browserify-zlib@^0.2.0:
   dependencies:
     pako "~1.0.5"
 
+browserslist@4.5.2:
+  version "4.5.2"
+  resolved "https://registry.yarnpkg.com/browserslist/-/browserslist-4.5.2.tgz#36ad281f040af684555a23c780f5c2081c752df0"
+  integrity sha512-zmJVLiKLrzko0iszd/V4SsjTaomFeoVzQGYYOYgRgsbh7WNh95RgDB0CmBdFWYs/3MyFSt69NypjL/h3iaddKQ==
+  dependencies:
+    caniuse-lite "^1.0.30000951"
+    electron-to-chromium "^1.3.116"
+    node-releases "^1.1.11"
+
 browserslist@^4.0.0, browserslist@^4.3.3:
   version "4.3.4"
   resolved "https://registry.yarnpkg.com/browserslist/-/browserslist-4.3.4.tgz#4477b737db6a1b07077275b24791e680d4300425"
@@ -1785,6 +1804,21 @@ camelcase@^4.0.0, camelcase@^4.1.0:
   resolved "https://registry.yarnpkg.com/camelcase/-/camelcase-4.1.0.tgz#d545635be1e33c542649c69173e5de6acfae34dd"
   integrity sha1-1UVjW+HjPFQmScaRc+Xeas+uNN0=
 
+caniuse-api@3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/caniuse-api/-/caniuse-api-3.0.0.tgz#5e4d90e2274961d46291997df599e3ed008ee4c0"
+  integrity sha512-bsTwuIg/BZZK/vreVTYYbSWoe2F+71P7K5QGEX+pT250DZbfU1MQ5prOKpPR+LL6uWKK3KMwMCAS74QB3Um1uw==
+  dependencies:
+    browserslist "^4.0.0"
+    caniuse-lite "^1.0.0"
+    lodash.memoize "^4.1.2"
+    lodash.uniq "^4.5.0"
+
+caniuse-lite@^1.0.0, caniuse-lite@^1.0.30000951:
+  version "1.0.30000955"
+  resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30000955.tgz#360fdb9a1e41d6dd996130411334e44a39e4446d"
+  integrity sha512-6AwmIKgqCYfDWWadRkAuZSHMQP4Mmy96xAXEdRBlN/luQhlRYOKgwOlZ9plpCOsVbBuqbTmGqDK3JUM/nlr8CA==
+
 caniuse-lite@^1.0.30000898, caniuse-lite@^1.0.30000899:
   version "1.0.30000903"
   resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30000903.tgz#86d46227759279b3db345ddbe778335dbba9e858"
@@ -3016,6 +3050,11 @@ electron-to-chromium@^1.3.113:
   resolved "https://registry.yarnpkg.com/electron-to-chromium/-/electron-to-chromium-1.3.113.tgz#b1ccf619df7295aea17bc6951dc689632629e4a9"
   integrity sha512-De+lPAxEcpxvqPTyZAXELNpRZXABRxf+uL/rSykstQhzj/B0l1150G/ExIIxKc16lI89Hgz81J0BHAcbTqK49g==
 
+electron-to-chromium@^1.3.116:
+  version "1.3.121"
+  resolved "https://registry.yarnpkg.com/electron-to-chromium/-/electron-to-chromium-1.3.121.tgz#761aaec1ec947b8ed3e9538177598d8f6ca3b5bd"
+  integrity sha512-ALxUkgrnQ6zg2SN9zHnwDcDRy577haGT9dqsbq8lfeAgmEUPC+58SrrU8vIHpGRf7SEyyBYy4mlfonDnoKxONw==
+
 electron-to-chromium@^1.3.82:
   version "1.3.82"
   resolved "https://registry.yarnpkg.com/electron-to-chromium/-/electron-to-chromium-1.3.82.tgz#7d13ae4437d2a783de3f4efba96b186c540b67b1"
@@ -5598,6 +5637,11 @@ lodash.get@^4.4.2:
   resolved "https://registry.yarnpkg.com/lodash.get/-/lodash.get-4.4.2.tgz#2d177f652fa31e939b4438d5341499dfa3825e99"
   integrity sha1-LRd/ZS+jHpObRDjVNBSZ36OCXpk=
 
+lodash.memoize@^4.1.2:
+  version "4.1.2"
+  resolved "https://registry.yarnpkg.com/lodash.memoize/-/lodash.memoize-4.1.2.tgz#bcc6c49a42a2840ed997f323eada5ecd182e0bfe"
+  integrity sha1-vMbEmkKihA7Zl/Mj6tpezRguC/4=
+
 lodash.tail@^4.1.1:
   version "4.1.1"
   resolved "https://registry.yarnpkg.com/lodash.tail/-/lodash.tail-4.1.1.tgz#d2333a36d9e7717c8ad2f7cacafec7c32b444664"
@@ -5618,6 +5662,11 @@ lodash.templatesettings@^4.0.0:
   dependencies:
     lodash._reinterpolate "~3.0.0"
 
+lodash.uniq@^4.5.0:
+  version "4.5.0"
+  resolved "https://registry.yarnpkg.com/lodash.uniq/-/lodash.uniq-4.5.0.tgz#d0225373aeb652adc1bc82e4945339a842754773"
+  integrity sha1-0CJTc662Uq3BvILklFM5qEJ1R3M=
+
 lodash@^4.16.6, lodash@^4.17.11, lodash@^4.17.5:
   version "4.17.11"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.11.tgz#b39ea6229ef607ecd89e2c8df12536891cac9b8d"
@@ -6293,6 +6342,13 @@ node-releases@^1.0.1:
   dependencies:
     semver "^5.3.0"
 
+node-releases@^1.1.11:
+  version "1.1.12"
+  resolved "https://registry.yarnpkg.com/node-releases/-/node-releases-1.1.12.tgz#1d6baf544316b5422fcd35efe18708370a4e7637"
+  integrity sha512-Y+AQ1xdjcgaEzpL65PBEF3fnl1FNKnDh9Zm+AUQLIlyyqtSc4u93jyMN4zrjMzdwKQ10RTr3tgY1x7qpsfF/xg==
+  dependencies:
+    semver "^5.3.0"
+
 node-releases@^1.1.8:
   version "1.1.8"
   resolved "https://registry.yarnpkg.com/node-releases/-/node-releases-1.1.8.tgz#32a63fff63c5e51b7e0f540ac95947d220fc6862"