angular-cli/packages/schematics/angular/migrations/update-8/differential-loading_spec.ts

/**
 * @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 { EmptyTree } from '@angular-devkit/schematics';
import { SchematicTestRunner, UnitTestTree } from '@angular-devkit/schematics/testing';


describe('Migration to version 8', () => {
  describe('Migrate ES5 projects to enable differential loading', () => {
    const tsConfigPath = '/tsconfig.json';
    const oldTsConfig = {
      compilerOptions: {
        module: 'es2015',
        moduleResolution: 'node',
        typeRoots: [
          'node_modules/@types',
        ],
      },
    };

    const schematicRunner = new SchematicTestRunner(
      'migrations',
      require.resolve('../migration-collection.json'),
    );

    let tree: UnitTestTree;

    beforeEach(async () => {
      tree = new UnitTestTree(new EmptyTree());
      tree = await schematicRunner.runExternalSchematicAsync(
        require.resolve('../../collection.json'), 'ng-new',
        {
          name: 'migration-test',
          version: '1.2.3',
          directory: '.',
        },
        tree,
      ).toPromise();
      tree.overwrite(tsConfigPath, JSON.stringify(oldTsConfig, null, 2));
    });

    it(`should update 'target' to es2015 when property exists`, () => {
      const tree2 = schematicRunner.runSchematic('migration-07', {}, tree.branch());
      const { target } = JSON.parse(tree2.readContent(tsConfigPath)).compilerOptions;
      expect(target).toBe('es2015');
    });

    it(`should create 'target' property when doesn't exists`, () => {
      const tree2 = schematicRunner.runSchematic('migration-07', {}, tree.branch());
      const compilerOptions = {
        ...oldTsConfig.compilerOptions,
        target: undefined,
      };

      tree.overwrite(tsConfigPath, JSON.stringify({ compilerOptions }, null, 2));
      const { target } = JSON.parse(tree2.readContent(tsConfigPath)).compilerOptions;
      expect(target).toBe('es2015');
    });

    it(`should update browserslist file to add an non evergreen browser`, () => {
      const tree2 = schematicRunner.runSchematic('migration-07', {}, tree.branch());
      expect(tree2.readContent('/browserslist')).toContain('Chrome 41');
    });

    it(`should create browserslist file if it doesn't exist`, () => {
      tree.delete('/browserslist');
      const tree2 = schematicRunner.runSchematic('migration-07', {}, tree.branch());
      expect(tree2.exists('/browserslist')).toBe(true);
      expect(tree2.readContent('/browserslist'))
        .toContain('Googlebot support');
    });
  });
});