@angular-devkit/build-angular
Version:
Angular Webpack Build Facade
60 lines (59 loc) • 2.21 kB
JavaScript
;
/**
* @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
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.BuildBrowserFeatures = void 0;
const browserslist = require("browserslist");
const caniuse_lite_1 = require("caniuse-lite");
const ts = require("typescript");
class BuildBrowserFeatures {
constructor(projectRoot, scriptTarget) {
this.projectRoot = projectRoot;
this.scriptTarget = scriptTarget;
this.supportedBrowsers = browserslist(undefined, { path: this.projectRoot });
this._es6TargetOrLater = this.scriptTarget > ts.ScriptTarget.ES5;
}
/**
* True, when one or more browsers requires ES5
* support and the scirpt target is ES2015 or greater.
*/
isDifferentialLoadingNeeded() {
return this._es6TargetOrLater && this.isEs5SupportNeeded();
}
/**
* True, when one or more browsers requires ES5 support
*/
isEs5SupportNeeded() {
return !this.isFeatureSupported('es6-module');
}
/**
* True, when a browser feature is supported partially or fully.
*/
isFeatureSupported(featureId) {
// y: feature is fully available
// n: feature is unavailable
// a: feature is partially supported
// x: feature is prefixed
const criteria = [
'y',
'a',
];
const data = caniuse_lite_1.feature(caniuse_lite_1.features[featureId]);
return !this.supportedBrowsers
.some(browser => {
const [agentId, version] = browser.split(' ');
const browserData = data.stats[agentId];
const featureStatus = (browserData && browserData[version]);
// We are only interested in the first character
// Ex: when 'a #4 #5', we only need to check for 'a'
// as for such cases we should polyfill these features as needed
return !featureStatus || !criteria.includes(featureStatus.charAt(0));
});
}
}
exports.BuildBrowserFeatures = BuildBrowserFeatures;