node-module-engine-host_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
 */

// tslint:disable:no-implicit-dependencies

import { SchematicEngine } from '@angular-devkit/schematics';
import * as fs from 'fs';
import * as os from 'os';
import * as path from 'path';
import { NodeModulesEngineHost } from './node-module-engine-host';

const TMP_DIR = process.env['TEST_TMPDIR'] || os.tmpdir();

describe('NodeModulesEngineHost', () => {
  let tmpDir!: string;
  let previousDir!: string;

  beforeEach(() => {
    tmpDir = fs.mkdtempSync(path.join(TMP_DIR,
        'angular-devkit-schematics-tools-node-module-engine-host'));
    previousDir = process.cwd();
    process.chdir(tmpDir);
  });

  afterEach(() => process.chdir(previousDir));

  /** Creates a fake NPM module that can be used to test the node module engine host. */
  function createFakeNpmModule() {
    fs.mkdirSync(path.join(tmpDir, 'node_modules'));
    fs.mkdirSync(path.join(tmpDir, 'node_modules/@angular/'));
    fs.mkdirSync(path.join(tmpDir, 'node_modules/@angular/core'));
    fs.mkdirSync(path.join(tmpDir, 'node_modules/@angular/core/schematics'));
    fs.writeFileSync(path.join(tmpDir, 'node_modules/@angular/core/package.json'),
      JSON.stringify({name: '@angular/core'}));
    fs.writeFileSync(path.join(tmpDir, 'node_modules/@angular/core/schematics/migrations.json'),
      JSON.stringify({schematics: {}}));
  }

  it('should properly create collections with explicit collection path', () => {
    createFakeNpmModule();

    const engineHost = new NodeModulesEngineHost();
    const engine = new SchematicEngine(engineHost);

    // Under Bazel 'require.resolve' is patched to use Bazel resolutions from the MANIFEST FILES.
    // Adding a temporary file won't be enough to make Bazel aware of this file.
    // We provide the full path here just to verify that the underlying logic works
    let prefix = '';
    if (process.env['BAZEL_TARGET']) {
      prefix = path.join(process.cwd(), 'node_modules');
    }

    expect(() => {
      engine.createCollection(path.join(prefix, '@angular/core', './schematics/migrations.json'));
    }).not.toThrow();
  });
});