hunk.code_window:   tags,
     virtualFs,
   } from '@angular-devkit/core';
   import { NodeJsSyncHost } from '@angular-devkit/core/node';
   import { createHash } from 'crypto';
   import * as findCacheDirectory from 'find-cache-dir';
   import * as fs from 'fs';
   import * as path from 'path';
   import { Observable, from, of } from 'rxjs';
  
hunk.labels: keep keep keep keep replace keep keep keep keep
hunk.file_path: packages/angular_devkit/build_angular/src/browser/index.ts
hunk.type: replace
file: /**
   * @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 { Path, normalize, virtualFs } from '@angular-devkit/core';
  import { toArray } from 'rxjs/operators';
  import { HostCreateTree, HostTree } from '../tree/host-tree';
  import { optimize } from '../tree/static';
  import { DryRunSink } from './dryrun';
  
  
  const host = new virtualFs.test.TestHost({
    '/hello': '',
    '/sub/file1': '',
    '/sub/directory/file2': '',
  });
  
  
  describe('DryRunSink', () => {
    it('works when creating everything', done => {
      const tree = new HostCreateTree(host);
  
      tree.create('/test', 'testing 1 2');
      const recorder = tree.beginUpdate('/test');
      recorder.insertLeft(8, 'testing ');
      tree.commitUpdate(recorder);
      tree.overwrite('/hello', 'world');
  
      const files = ['/hello', '/sub/directory/file2', '/sub/file1', '/test'];
      const treeFiles: Path[] = [];
      tree.visit(path => treeFiles.push(path));
      treeFiles.sort();
      expect(treeFiles).toEqual(files.map(normalize));
  
      const sink = new DryRunSink(new virtualFs.SimpleMemoryHost());
      sink.reporter.pipe(toArray())
        .toPromise()
        .then(infos => {
          expect(infos.length).toBe(4);
          for (const info of infos) {
            expect(info.kind).toBe('create');
          }
        })
        .then(done, done.fail);
  
      sink.commit(optimize(tree))
        .toPromise().then(done, done.fail);
    });
  
    it('works with root', done => {
      const tree = new HostTree(host);
  
      tree.create('/test', 'testing 1 2');
      const recorder = tree.beginUpdate('/test');
      recorder.insertLeft(8, 'testing ');
      tree.commitUpdate(recorder);
      tree.overwrite('/hello', 'world');
  
      const files = ['/hello', '/sub/directory/file2', '/sub/file1', '/test'];
      const treeFiles: Path[] = [];
      tree.visit(path => treeFiles.push(path));
      treeFiles.sort();
      expect(treeFiles).toEqual(files.map(normalize));
  
      // Need to create this file on the filesystem, otherwise the commit phase will fail.
      const outputHost = new virtualFs.SimpleMemoryHost();
      outputHost.write(normalize('/hello'), virtualFs.stringToFileBuffer('')).subscribe();
  
      const sink = new DryRunSink(outputHost);
      sink.reporter.pipe(toArray())
        .toPromise()
        .then(infos => {
          expect(infos.map(x => x.kind)).toEqual(['create', 'update']);
        })
        .then(done, done.fail);
  
      sink.commit(optimize(tree))
        .toPromise().then(done, done.fail);
    });
  });
  