How to use watchmanCrawl method in Jest

Best JavaScript code snippet using jest

58watchman.test.js

Source:58watchman.test.js

...100  afterEach(() => {101    watchman.Client.mock.instances[0].command.mockClear();102  });103  test('returns a list of all files when there are no clocks', () =>104    watchmanCrawl({105      data: {106        clocks: new Map(),107        files: new Map(),108      },109      extensions: ['js', 'json'],110      ignore: pearMatcher,111      rootDir: ROOT_MOCK,112      roots: ROOTS,113    }).then(data => {114      const client = watchman.Client.mock.instances[0];115      const calls = client.command.mock.calls;116      expect(client.on).toBeCalled();117      expect(client.on).toBeCalledWith('error', expect.any(Function));118      // Call 0 and 1 are for ['watch-project']119      expect(calls[0][0][0]).toEqual('watch-project');120      expect(calls[1][0][0]).toEqual('watch-project');121      // Call 2 is the query122      const query = calls[2][0];123      expect(query[0]).toEqual('query');124      expect(query[2].expression).toEqual([125        'allof',126        ['type', 'f'],127        ['anyof', ['suffix', 'js'], ['suffix', 'json']],128        ['anyof', ['dirname', 'fruits'], ['dirname', 'vegetables']],129      ]);130      expect(query[2].fields).toEqual(['name', 'exists', 'mtime_ms']);131      expect(query[2].glob).toEqual([132        'fruits/**/*.js',133        'fruits/**/*.json',134        'vegetables/**/*.js',135        'vegetables/**/*.json',136      ]);137      expect(data.clocks).toEqual(138        createMap({139          '': 'c:fake-clock:1',140        }),141      );142      expect(data.files).toEqual(mockFiles);143      expect(client.end).toBeCalled();144    }));145  test('applies the mapper when needed', () => {146    mockResponse = {147      'list-capabilities': {148        [undefined]: {149          capabilities: ['field-content.sha1hex'],150        },151      },152      query: {153        [ROOT_MOCK]: {154          clock: 'c:fake-clock:1',155          files: [156            {157              exists: true,158              mtime_ms: {toNumber: () => 33},159              name: 'vegetables/durian.zip',160            },161          ],162          is_fresh_instance: true,163          version: '4.5.0',164        },165      },166      'watch-project': WATCH_PROJECT_MOCK,167    };168    return watchmanCrawl({169      data: {170        clocks: new Map(),171        files: new Map(),172      },173      extensions: ['js', 'json', 'zip'],174      ignore: pearMatcher,175      mapper: n =>176        n.endsWith('.zip')177          ? [path.join(n, 'foo.1.js'), path.join(n, 'foo.2.js')]178          : null,179      rootDir: ROOT_MOCK,180      roots: ROOTS,181    }).then(data => {182      expect(data.files).toEqual(183        createMap({184          [path.join(DURIAN_RELATIVE, 'foo.1.js')]: ['', 33, 0, [], null],185          [path.join(DURIAN_RELATIVE, 'foo.2.js')]: ['', 33, 0, [], null],186        }),187      );188    });189  });190  test('updates the file object when the clock is given', () => {191    mockResponse = {192      'list-capabilities': {193        [undefined]: {194          capabilities: ['field-content.sha1hex'],195        },196      },197      query: {198        [ROOT_MOCK]: {199          clock: 'c:fake-clock:2',200          files: [201            {202              exists: true,203              mtime_ms: {toNumber: () => 42},204              name: 'fruits/kiwi.js',205            },206            {207              exists: false,208              mtime_ms: null,209              name: 'fruits/tomato.js',210            },211          ],212          is_fresh_instance: false,213          version: '4.5.0',214        },215      },216      'watch-project': WATCH_PROJECT_MOCK,217    };218    const clocks = createMap({219      '': 'c:fake-clock:1',220    });221    return watchmanCrawl({222      data: {223        clocks,224        files: mockFiles,225      },226      extensions: ['js', 'json'],227      ignore: pearMatcher,228      rootDir: ROOT_MOCK,229      roots: ROOTS,230    }).then(data => {231      // The object was reused.232      expect(data.files).toBe(mockFiles);233      expect(data.clocks).toEqual(234        createMap({235          '': 'c:fake-clock:2',236        }),237      );238      expect(data.files).toEqual(239        createMap({240          [KIWI_RELATIVE]: ['', 42, 0, [], null],241          [MELON_RELATIVE]: ['', 33, 0, [], null],242          [STRAWBERRY_RELATIVE]: ['', 30, 0, [], null],243        }),244      );245    });246  });247  test('resets the file object when watchman is restarted', () => {248    const mockTomatoSha1 = '321f6b7e8bf7f29aab89c5e41a555b1b0baa41a9';249    mockResponse = {250      'list-capabilities': {251        [undefined]: {252          capabilities: ['field-content.sha1hex'],253        },254      },255      query: {256        [ROOT_MOCK]: {257          clock: 'c:fake-clock:3',258          files: [259            {260              exists: true,261              mtime_ms: {toNumber: () => 42},262              name: 'fruits/kiwi.js',263            },264            {265              exists: true,266              mtime_ms: {toNumber: () => 41},267              name: 'fruits/banana.js',268            },269            {270              'content.sha1hex': mockTomatoSha1,271              exists: true,272              mtime_ms: {toNumber: () => 76},273              name: 'fruits/tomato.js',274            },275          ],276          is_fresh_instance: true,277          version: '4.5.0',278        },279      },280      'watch-project': WATCH_PROJECT_MOCK,281    };282    const mockBananaMetadata = ['Banana', 41, 1, ['Raspberry'], null];283    mockFiles.set(BANANA_RELATIVE, mockBananaMetadata);284    const mockTomatoMetadata = ['Tomato', 31, 1, [], mockTomatoSha1];285    mockFiles.set(TOMATO_RELATIVE, mockTomatoMetadata);286    const clocks = createMap({287      '': 'c:fake-clock:1',288    });289    return watchmanCrawl({290      data: {291        clocks,292        files: mockFiles,293      },294      extensions: ['js', 'json'],295      ignore: pearMatcher,296      rootDir: ROOT_MOCK,297      roots: ROOTS,298    }).then(data => {299      // The file object was *not* reused.300      expect(data.files).not.toBe(mockFiles);301      expect(data.clocks).toEqual(302        createMap({303          '': 'c:fake-clock:3',304        }),305      );306      // /fruits/strawberry.js was removed from the file list.307      expect(data.files).toEqual(308        createMap({309          [BANANA_RELATIVE]: mockBananaMetadata,310          [KIWI_RELATIVE]: ['', 42, 0, [], null],311          [TOMATO_RELATIVE]: ['Tomato', 76, 1, [], mockTomatoSha1],312        }),313      );314      // Even though the file list was reset, old file objects are still reused315      // if no changes have been made316      expect(data.files.get(BANANA_RELATIVE)).toBe(mockBananaMetadata);317      // Old file objects are not reused if they have a different mtime318      expect(data.files.get(TOMATO_RELATIVE)).not.toBe(mockTomatoMetadata);319    });320  });321  test('properly resets the file map when only one watcher is reset', () => {322    mockResponse = {323      'list-capabilities': {324        [undefined]: {325          capabilities: ['field-content.sha1hex'],326        },327      },328      query: {329        [FRUITS]: {330          clock: 'c:fake-clock:3',331          files: [332            {333              exists: true,334              mtime_ms: {toNumber: () => 42},335              name: 'kiwi.js',336            },337          ],338          is_fresh_instance: false,339          version: '4.5.0',340        },341        [VEGETABLES]: {342          clock: 'c:fake-clock:4',343          files: [344            {345              exists: true,346              mtime_ms: {toNumber: () => 33},347              name: 'melon.json',348            },349          ],350          is_fresh_instance: true,351          version: '4.5.0',352        },353      },354      'watch-project': {355        [FRUITS]: {356          watch: forcePOSIXPaths(FRUITS),357        },358        [VEGETABLES]: {359          watch: forcePOSIXPaths(VEGETABLES),360        },361      },362    };363    const clocks = createMap({364      [FRUITS_RELATIVE]: 'c:fake-clock:1',365      [VEGETABLES_RELATIVE]: 'c:fake-clock:2',366    });367    return watchmanCrawl({368      data: {369        clocks,370        files: mockFiles,371      },372      extensions: ['js', 'json'],373      ignore: pearMatcher,374      rootDir: ROOT_MOCK,375      roots: ROOTS,376    }).then(data => {377      expect(data.clocks).toEqual(378        createMap({379          [FRUITS_RELATIVE]: 'c:fake-clock:3',380          [VEGETABLES_RELATIVE]: 'c:fake-clock:4',381        }),382      );383      expect(data.files).toEqual(384        createMap({385          [KIWI_RELATIVE]: ['', 42, 0, [], null],386          [MELON_RELATIVE]: ['', 33, 0, [], null],387        }),388      );389    });390  });391  test('does not add directory filters to query when watching a ROOT', () => {392    mockResponse = {393      'list-capabilities': {394        [undefined]: {395          capabilities: ['field-content.sha1hex'],396        },397      },398      query: {399        [ROOT_MOCK]: {400          clock: 'c:fake-clock:1',401          files: [],402          is_fresh_instance: false,403          version: '4.5.0',404        },405      },406      'watch-project': {407        [FRUITS]: {408          relative_path: 'fruits',409          watch: forcePOSIXPaths(ROOT_MOCK),410        },411        [ROOT_MOCK]: {412          watch: forcePOSIXPaths(ROOT_MOCK),413        },414        [VEGETABLES]: {415          relative_path: 'vegetables',416          watch: forcePOSIXPaths(ROOT_MOCK),417        },418      },419    };420    return watchmanCrawl({421      data: {422        clocks: new Map(),423        files: new Map(),424      },425      extensions: ['js', 'json'],426      ignore: pearMatcher,427      rootDir: ROOT_MOCK,428      roots: [...ROOTS, ROOT_MOCK],429    }).then(data => {430      const client = watchman.Client.mock.instances[0];431      const calls = client.command.mock.calls;432      expect(client.on).toBeCalled();433      expect(client.on).toBeCalledWith('error', expect.any(Function));434      // First 3 calls are for ['watch-project']435      expect(calls[0][0][0]).toEqual('watch-project');436      expect(calls[1][0][0]).toEqual('watch-project');437      expect(calls[2][0][0]).toEqual('watch-project');438      // Call 4 is the query439      const query = calls[3][0];440      expect(query[0]).toEqual('query');441      expect(query[2].expression).toEqual([442        'allof',443        ['type', 'f'],444        ['anyof', ['suffix', 'js'], ['suffix', 'json']],445      ]);446      expect(query[2].fields).toEqual(['name', 'exists', 'mtime_ms']);447      expect(query[2].glob).toEqual(['**/*.js', '**/*.json']);448      expect(data.clocks).toEqual(449        createMap({450          '': 'c:fake-clock:1',451        }),452      );453      expect(data.files).toEqual(createMap({}));454      expect(client.end).toBeCalled();455    });456  });457  test('SHA-1 requested and available', async () => {458    mockResponse = {459      'list-capabilities': {460        [undefined]: {461          capabilities: ['field-content.sha1hex'],462        },463      },464      query: {465        [ROOT_MOCK]: {466          clock: 'c:fake-clock:1',467          files: [],468          is_fresh_instance: false,469          version: '4.5.0',470        },471      },472      'watch-project': {473        [ROOT_MOCK]: {474          watch: forcePOSIXPaths(ROOT_MOCK),475        },476      },477    };478    await watchmanCrawl({479      computeSha1: true,480      data: {481        clocks: new Map(),482        files: new Map(),483      },484      extensions: ['js', 'json'],485      rootDir: ROOT_MOCK,486      roots: [ROOT_MOCK],487    });488    const client = watchman.Client.mock.instances[0];489    const calls = client.command.mock.calls;490    expect(calls[0][0]).toEqual(['list-capabilities']);491    expect(calls[2][0][2].fields).toContain('content.sha1hex');492  });493  test('SHA-1 requested and NOT available', async () => {494    mockResponse = {495      'list-capabilities': {496        [undefined]: {497          capabilities: [],498        },499      },500      query: {501        [ROOT_MOCK]: {502          clock: 'c:fake-clock:1',503          files: [],504          is_fresh_instance: false,505          version: '4.5.0',506        },507      },508      'watch-project': {509        [ROOT_MOCK]: {510          watch: forcePOSIXPaths(ROOT_MOCK),511        },512      },513    };514    await watchmanCrawl({515      computeSha1: true,516      data: {517        clocks: new Map(),518        files: new Map(),519      },520      extensions: ['js', 'json'],521      rootDir: ROOT_MOCK,522      roots: [ROOT_MOCK],523    });524    const client = watchman.Client.mock.instances[0];525    const calls = client.command.mock.calls;526    expect(calls[0][0]).toEqual(['list-capabilities']);527    expect(calls[2][0][2].fields).not.toContain('content.sha1hex');528  });...

watchman.test.js

Source:watchman.test.js

...100  afterEach(() => {101    watchman.Client.mock.instances[0].command.mockClear();102  });103  test('returns a list of all files when there are no clocks', () =>104    watchmanCrawl({105      data: {106        clocks: new Map(),107        files: new Map(),108      },109      extensions: ['js', 'json'],110      ignore: pearMatcher,111      rootDir: ROOT_MOCK,112      roots: ROOTS,113    }).then(data => {114      const client = watchman.Client.mock.instances[0];115      const calls = client.command.mock.calls;116      expect(client.on).toBeCalled();117      expect(client.on).toBeCalledWith('error', expect.any(Function));118      // Call 0 and 1 are for ['watch-project']119      expect(calls[0][0][0]).toEqual('watch-project');120      expect(calls[1][0][0]).toEqual('watch-project');121      // Call 2 is the query122      const query = calls[2][0];123      expect(query[0]).toEqual('query');124      expect(query[2].expression).toEqual([125        'allof',126        ['type', 'f'],127        ['anyof', ['suffix', 'js'], ['suffix', 'json']],128        ['anyof', ['dirname', 'fruits'], ['dirname', 'vegetables']],129      ]);130      expect(query[2].fields).toEqual(['name', 'exists', 'mtime_ms']);131      expect(query[2].glob).toEqual([132        'fruits/**/*.js',133        'fruits/**/*.json',134        'vegetables/**/*.js',135        'vegetables/**/*.json',136      ]);137      expect(data.clocks).toEqual(138        createMap({139          '': 'c:fake-clock:1',140        }),141      );142      expect(data.files).toEqual(mockFiles);143      expect(client.end).toBeCalled();144    }));145  test('applies the mapper when needed', () => {146    mockResponse = {147      'list-capabilities': {148        [undefined]: {149          capabilities: ['field-content.sha1hex'],150        },151      },152      query: {153        [ROOT_MOCK]: {154          clock: 'c:fake-clock:1',155          files: [156            {157              exists: true,158              mtime_ms: {toNumber: () => 33},159              name: 'vegetables/durian.zip',160            },161          ],162          is_fresh_instance: true,163          version: '4.5.0',164        },165      },166      'watch-project': WATCH_PROJECT_MOCK,167    };168    return watchmanCrawl({169      data: {170        clocks: new Map(),171        files: new Map(),172      },173      extensions: ['js', 'json', 'zip'],174      ignore: pearMatcher,175      mapper: n =>176        n.endsWith('.zip')177          ? [path.join(n, 'foo.1.js'), path.join(n, 'foo.2.js')]178          : null,179      rootDir: ROOT_MOCK,180      roots: ROOTS,181    }).then(data => {182      expect(data.files).toEqual(183        createMap({184          [path.join(DURIAN_RELATIVE, 'foo.1.js')]: ['', 33, 0, [], null],185          [path.join(DURIAN_RELATIVE, 'foo.2.js')]: ['', 33, 0, [], null],186        }),187      );188    });189  });190  test('updates the file object when the clock is given', () => {191    mockResponse = {192      'list-capabilities': {193        [undefined]: {194          capabilities: ['field-content.sha1hex'],195        },196      },197      query: {198        [ROOT_MOCK]: {199          clock: 'c:fake-clock:2',200          files: [201            {202              exists: true,203              mtime_ms: {toNumber: () => 42},204              name: 'fruits/kiwi.js',205            },206            {207              exists: false,208              mtime_ms: null,209              name: 'fruits/tomato.js',210            },211          ],212          is_fresh_instance: false,213          version: '4.5.0',214        },215      },216      'watch-project': WATCH_PROJECT_MOCK,217    };218    const clocks = createMap({219      '': 'c:fake-clock:1',220    });221    return watchmanCrawl({222      data: {223        clocks,224        files: mockFiles,225      },226      extensions: ['js', 'json'],227      ignore: pearMatcher,228      rootDir: ROOT_MOCK,229      roots: ROOTS,230    }).then(data => {231      // The object was reused.232      expect(data.files).toBe(mockFiles);233      expect(data.clocks).toEqual(234        createMap({235          '': 'c:fake-clock:2',236        }),237      );238      expect(data.files).toEqual(239        createMap({240          [KIWI_RELATIVE]: ['', 42, 0, [], null],241          [MELON_RELATIVE]: ['', 33, 0, [], null],242          [STRAWBERRY_RELATIVE]: ['', 30, 0, [], null],243        }),244      );245    });246  });247  test('resets the file object when watchman is restarted', () => {248    const mockTomatoSha1 = '321f6b7e8bf7f29aab89c5e41a555b1b0baa41a9';249    mockResponse = {250      'list-capabilities': {251        [undefined]: {252          capabilities: ['field-content.sha1hex'],253        },254      },255      query: {256        [ROOT_MOCK]: {257          clock: 'c:fake-clock:3',258          files: [259            {260              exists: true,261              mtime_ms: {toNumber: () => 42},262              name: 'fruits/kiwi.js',263            },264            {265              exists: true,266              mtime_ms: {toNumber: () => 41},267              name: 'fruits/banana.js',268            },269            {270              'content.sha1hex': mockTomatoSha1,271              exists: true,272              mtime_ms: {toNumber: () => 76},273              name: 'fruits/tomato.js',274            },275          ],276          is_fresh_instance: true,277          version: '4.5.0',278        },279      },280      'watch-project': WATCH_PROJECT_MOCK,281    };282    const mockBananaMetadata = ['Banana', 41, 1, ['Raspberry'], null];283    mockFiles.set(BANANA_RELATIVE, mockBananaMetadata);284    const mockTomatoMetadata = ['Tomato', 31, 1, [], mockTomatoSha1];285    mockFiles.set(TOMATO_RELATIVE, mockTomatoMetadata);286    const clocks = createMap({287      '': 'c:fake-clock:1',288    });289    return watchmanCrawl({290      data: {291        clocks,292        files: mockFiles,293      },294      extensions: ['js', 'json'],295      ignore: pearMatcher,296      rootDir: ROOT_MOCK,297      roots: ROOTS,298    }).then(data => {299      // The file object was *not* reused.300      expect(data.files).not.toBe(mockFiles);301      expect(data.clocks).toEqual(302        createMap({303          '': 'c:fake-clock:3',304        }),305      );306      // /fruits/strawberry.js was removed from the file list.307      expect(data.files).toEqual(308        createMap({309          [BANANA_RELATIVE]: mockBananaMetadata,310          [KIWI_RELATIVE]: ['', 42, 0, [], null],311          [TOMATO_RELATIVE]: ['Tomato', 76, 1, [], mockTomatoSha1],312        }),313      );314      // Even though the file list was reset, old file objects are still reused315      // if no changes have been made316      expect(data.files.get(BANANA_RELATIVE)).toBe(mockBananaMetadata);317      // Old file objects are not reused if they have a different mtime318      expect(data.files.get(TOMATO_RELATIVE)).not.toBe(mockTomatoMetadata);319    });320  });321  test('properly resets the file map when only one watcher is reset', () => {322    mockResponse = {323      'list-capabilities': {324        [undefined]: {325          capabilities: ['field-content.sha1hex'],326        },327      },328      query: {329        [FRUITS]: {330          clock: 'c:fake-clock:3',331          files: [332            {333              exists: true,334              mtime_ms: {toNumber: () => 42},335              name: 'kiwi.js',336            },337          ],338          is_fresh_instance: false,339          version: '4.5.0',340        },341        [VEGETABLES]: {342          clock: 'c:fake-clock:4',343          files: [344            {345              exists: true,346              mtime_ms: {toNumber: () => 33},347              name: 'melon.json',348            },349          ],350          is_fresh_instance: true,351          version: '4.5.0',352        },353      },354      'watch-project': {355        [FRUITS]: {356          watch: forcePOSIXPaths(FRUITS),357        },358        [VEGETABLES]: {359          watch: forcePOSIXPaths(VEGETABLES),360        },361      },362    };363    const clocks = createMap({364      [FRUITS_RELATIVE]: 'c:fake-clock:1',365      [VEGETABLES_RELATIVE]: 'c:fake-clock:2',366    });367    return watchmanCrawl({368      data: {369        clocks,370        files: mockFiles,371      },372      extensions: ['js', 'json'],373      ignore: pearMatcher,374      rootDir: ROOT_MOCK,375      roots: ROOTS,376    }).then(data => {377      expect(data.clocks).toEqual(378        createMap({379          [FRUITS_RELATIVE]: 'c:fake-clock:3',380          [VEGETABLES_RELATIVE]: 'c:fake-clock:4',381        }),382      );383      expect(data.files).toEqual(384        createMap({385          [KIWI_RELATIVE]: ['', 42, 0, [], null],386          [MELON_RELATIVE]: ['', 33, 0, [], null],387        }),388      );389    });390  });391  test('does not add directory filters to query when watching a ROOT', () => {392    mockResponse = {393      'list-capabilities': {394        [undefined]: {395          capabilities: ['field-content.sha1hex'],396        },397      },398      query: {399        [ROOT_MOCK]: {400          clock: 'c:fake-clock:1',401          files: [],402          is_fresh_instance: false,403          version: '4.5.0',404        },405      },406      'watch-project': {407        [FRUITS]: {408          relative_path: 'fruits',409          watch: forcePOSIXPaths(ROOT_MOCK),410        },411        [ROOT_MOCK]: {412          watch: forcePOSIXPaths(ROOT_MOCK),413        },414        [VEGETABLES]: {415          relative_path: 'vegetables',416          watch: forcePOSIXPaths(ROOT_MOCK),417        },418      },419    };420    return watchmanCrawl({421      data: {422        clocks: new Map(),423        files: new Map(),424      },425      extensions: ['js', 'json'],426      ignore: pearMatcher,427      rootDir: ROOT_MOCK,428      roots: [...ROOTS, ROOT_MOCK],429    }).then(data => {430      const client = watchman.Client.mock.instances[0];431      const calls = client.command.mock.calls;432      expect(client.on).toBeCalled();433      expect(client.on).toBeCalledWith('error', expect.any(Function));434      // First 3 calls are for ['watch-project']435      expect(calls[0][0][0]).toEqual('watch-project');436      expect(calls[1][0][0]).toEqual('watch-project');437      expect(calls[2][0][0]).toEqual('watch-project');438      // Call 4 is the query439      const query = calls[3][0];440      expect(query[0]).toEqual('query');441      expect(query[2].expression).toEqual([442        'allof',443        ['type', 'f'],444        ['anyof', ['suffix', 'js'], ['suffix', 'json']],445      ]);446      expect(query[2].fields).toEqual(['name', 'exists', 'mtime_ms']);447      expect(query[2].glob).toEqual(['**/*.js', '**/*.json']);448      expect(data.clocks).toEqual(449        createMap({450          '': 'c:fake-clock:1',451        }),452      );453      expect(data.files).toEqual(createMap({}));454      expect(client.end).toBeCalled();455    });456  });457  test('SHA-1 requested and available', async () => {458    mockResponse = {459      'list-capabilities': {460        [undefined]: {461          capabilities: ['field-content.sha1hex'],462        },463      },464      query: {465        [ROOT_MOCK]: {466          clock: 'c:fake-clock:1',467          files: [],468          is_fresh_instance: false,469          version: '4.5.0',470        },471      },472      'watch-project': {473        [ROOT_MOCK]: {474          watch: forcePOSIXPaths(ROOT_MOCK),475        },476      },477    };478    await watchmanCrawl({479      computeSha1: true,480      data: {481        clocks: new Map(),482        files: new Map(),483      },484      extensions: ['js', 'json'],485      rootDir: ROOT_MOCK,486      roots: [ROOT_MOCK],487    });488    const client = watchman.Client.mock.instances[0];489    const calls = client.command.mock.calls;490    expect(calls[0][0]).toEqual(['list-capabilities']);491    expect(calls[2][0][2].fields).toContain('content.sha1hex');492  });493  test('SHA-1 requested and NOT available', async () => {494    mockResponse = {495      'list-capabilities': {496        [undefined]: {497          capabilities: [],498        },499      },500      query: {501        [ROOT_MOCK]: {502          clock: 'c:fake-clock:1',503          files: [],504          is_fresh_instance: false,505          version: '4.5.0',506        },507      },508      'watch-project': {509        [ROOT_MOCK]: {510          watch: forcePOSIXPaths(ROOT_MOCK),511        },512      },513    };514    await watchmanCrawl({515      computeSha1: true,516      data: {517        clocks: new Map(),518        files: new Map(),519      },520      extensions: ['js', 'json'],521      rootDir: ROOT_MOCK,522      roots: [ROOT_MOCK],523    });524    const client = watchman.Client.mock.instances[0];525    const calls = client.command.mock.calls;526    expect(calls[0][0]).toEqual(['list-capabilities']);527    expect(calls[2][0][2].fields).not.toContain('content.sha1hex');528  });...

watchman-test.js

Source:watchman-test.js

...77    const watchman = require('fb-watchman');78    const path = require('../../fastpath');79    const originalPathRelative = path.relative;80    path.relative = jest.fn(from => '/root-mock' + from);81    return watchmanCrawl(82      ['/fruits', '/vegetables'],83      ['js', 'json'],84      pearMatcher,85      {86        clocks: Object.create(null),87        files: Object.create(null),88      }89    ).then(data => {90      const client = watchman.Client.mock.instances[0];91      const calls = client.command.mock.calls;92      expect(client.on).toBeCalled();93      expect(client.on).toBeCalledWith('error', jasmine.any(Function));94      // Call 0 and 1 are for ['watch-project']95      expect(calls[0][0][0]).toEqual('watch-project');96      expect(calls[1][0][0]).toEqual('watch-project');97      // Calls 2 and 3 are queries98      const query1 = calls[2][0];99      const query2 = calls[3][0];100      expect(query1[0]).toEqual('query');101      expect(query2[0]).toEqual('query');102      expect(query1[2].expression).toEqual([103        'allof',104        ['type', 'f'],105        ['anyof', ['suffix', 'js'], ['suffix', 'json']],106        ['anyof', ['dirname', '/root-mock/fruits']],107      ]);108      expect(query2[2].expression).toEqual([109        'allof',110        ['type', 'f'],111        ['anyof', ['suffix', 'js'], ['suffix', 'json']],112        ['anyof', ['dirname', '/root-mock/vegetables']],113      ]);114      expect(query1[2].fields).toEqual(['name', 'exists', 'mtime_ms']);115      expect(query2[2].fields).toEqual(['name', 'exists', 'mtime_ms']);116      expect(query1[2].suffix).toEqual(['js', 'json']);117      expect(query2[2].suffix).toEqual(['js', 'json']);118      expect(data.clocks).toEqual({119        '/fruits': 'c:fake-clock:1',120        '/vegetables': 'c:fake-clock:2',121      });122      expect(data.files).toEqual(mockFiles);123      path.relative = originalPathRelative;124      expect(client.end).toBeCalled();125    });126  });127  it('updates the file object when the clock is given', () => {128    mockResponse = {129      '/fruits': {130        version: '4.5.0',131        clock: 'c:fake-clock:3',132        is_fresh_instance: false,133        files: [134          {135            name: 'kiwi.js',136            exists: true,137            mtime_ms: {toNumber: () => 42},138          },139          {140            name: 'tomato.js',141            exists: false,142            mtime_ms: null,143          },144        ],145      },146      '/vegetables': {147        version: '4.5.0',148        clock: 'c:fake-clock:4',149        files: [],150      },151    };152    const clocks = Object.assign(Object.create(null), {153      '/fruits': 'c:fake-clock:1',154      '/vegetables': 'c:fake-clock:2',155    });156    return watchmanCrawl(157      ['/fruits', '/vegetables'],158      ['js', 'json'],159      pearMatcher,160      {161        clocks,162        files: mockFiles,163      }164    ).then(data => {165      // The object was reused.166      expect(data.files).toBe(mockFiles);167      expect(data.clocks).toEqual({168        '/fruits': 'c:fake-clock:3',169        '/vegetables': 'c:fake-clock:4',170      });171      expect(data.files).toEqual({172        '/fruits/strawberry.js': ['', 30, 0, []],173        '/fruits/kiwi.js': ['', 42, 0, []],174        '/vegetables/melon.json': ['', 33, 0, []],175      });176    });177  });178  it('resets the file object when watchman is restarted', () => {179    mockResponse = {180      '/fruits': {181        version: '4.5.0',182        clock: 'c:fake-clock:5',183        is_fresh_instance: true,184        files: [185          {186            name: 'kiwi.js',187            exists: true,188            mtime_ms: {toNumber: () => 42},189          },190          {191            name: 'banana.js',192            exists: true,193            mtime_ms: {toNumber: () => 41},194          },195          {196            name: 'tomato.js',197            exists: true,198            mtime_ms: {toNumber: () => 31},199          },200        ],201      },202      '/vegetables': {203        version: '4.5.0',204        clock: 'c:fake-clock:6',205        is_fresh_instance: true,206        files: [],207      },208    };209    const mockMetadata = ['Banana', 41, 1, ['Raspberry']];210    mockFiles['/fruits/banana.js'] = mockMetadata;211    const clocks = Object.assign(Object.create(null), {212      '/fruits': 'c:fake-clock:1',213      '/vegetables': 'c:fake-clock:2',214    });215    return watchmanCrawl(216      ['/fruits', '/vegetables'],217      ['js', 'json'],218      pearMatcher,219      {220        clocks,221        files: mockFiles,222      }223    ).then(data => {224      // The file object was *not* reused.225      expect(data.files).not.toBe(mockFiles);226      expect(data.clocks).toEqual({227        '/fruits': 'c:fake-clock:5',228        '/vegetables': 'c:fake-clock:6',229      });230      // /fruits/strawberry.js was removed from the file list.231      expect(data.files).toEqual({232        '/fruits/kiwi.js': ['', 42, 0, []],233        '/fruits/banana.js': mockMetadata,234        '/fruits/tomato.js': mockFiles['/fruits/tomato.js'],235      });236      // Even though the file list was reset, old file objects are still reused237      // if no changes have been made.238      expect(data.files['/fruits/banana.js']).toBe(mockMetadata);239      expect(data.files['/fruits/tomato.js'])240        .toBe(mockFiles['/fruits/tomato.js']);241    });242  });243  it('properly resets the file map when only one watcher is reset', () => {244    mockResponse = {245      '/fruits': {246        version: '4.5.0',247        clock: 'c:fake-clock:3',248        is_fresh_instance: false,249        files: [250          {251            name: 'kiwi.js',252            exists: true,253            mtime_ms: {toNumber: () => 42},254          },255        ],256      },257      '/vegetables': {258        version: '4.5.0',259        clock: 'c:fake-clock:4',260        is_fresh_instance: true,261        files: [262          {263            name: 'melon.json',264            exists: true,265            mtime_ms: {toNumber: () => 33},266          },267        ],268      },269    };270    const clocks = Object.assign(Object.create(null), {271      '/fruits': 'c:fake-clock:1',272      '/vegetables': 'c:fake-clock:2',273    });274    return watchmanCrawl(275      ['/fruits', '/vegetables'],276      ['js', 'json'],277      pearMatcher,278      {279        clocks,280        files: mockFiles,281      }282    ).then(data => {283      expect(data.clocks).toEqual({284        '/fruits': 'c:fake-clock:3',285        '/vegetables': 'c:fake-clock:4',286      });287      expect(data.files).toEqual({288        '/fruits/kiwi.js': ['', 42, 0, []],...

index.js

Source:index.js

...3const watchmanCrawl = require('./watchman');4function crawl(roots, options) {5  const {fileWatcher} = options;6  return (fileWatcher ? fileWatcher.isWatchman() : Promise.resolve(false)).then(7    isWatchman => isWatchman ? watchmanCrawl(roots, options) : nodeCrawl(roots, options)8  );9}...

Jest Testing Tutorial

LambdaTest’s Jest Testing Tutorial covers step-by-step guides around Jest with code examples to help you be proficient with the Jest framework. The Jest tutorial has chapters to help you learn right from the basics of Jest framework to code-based tutorials around testing react apps with Jest, perform snapshot testing, import ES modules and more.

Chapters

What is Jest Framework
Advantages of Jest - Jest has 3,898,000 GitHub repositories, as mentioned on its official website. Learn what makes Jest special and why Jest has gained popularity among the testing and developer community.
Jest Installation - All the prerequisites and set up steps needed to help you start Jest automation testing.
Using Jest with NodeJS Project - Learn how to leverage Jest framework to automate testing using a NodeJS Project.
Writing First Test for Jest Framework - Get started with code-based tutorial to help you write and execute your first Jest framework testing script.
Jest Vocabulary - Learn the industry renowned and official jargons of the Jest framework by digging deep into the Jest vocabulary.
Unit Testing with Jest - Step-by-step tutorial to help you execute unit testing with Jest framework.
Jest Basics - Learn about the most pivotal and basic features which makes Jest special.
Jest Parameterized Tests - Avoid code duplication and fasten automation testing with Jest using parameterized tests. Parameterization allows you to trigger the same test scenario over different test configurations by incorporating parameters.
Jest Matchers - Enforce assertions better with the help of matchers. Matchers help you compare the actual output with the expected one. Here is an example to see if the object is acquired from the correct class or not. -

|it('check_object_of_Car', () => { expect(newCar()).toBeInstanceOf(Car); });| | :- |

Jest Hooks: Setup and Teardown - Learn how to set up conditions which needs to be followed by the test execution and incorporate a tear down function to free resources after the execution is complete.
Jest Code Coverage - Unsure there is no code left unchecked in your application. Jest gives a specific flag called --coverage to help you generate code coverage.
HTML Report Generation - Learn how to create a comprehensive HTML report based on your Jest test execution.
Testing React app using Jest Framework - Learn how to test your react web-application with Jest framework in this detailed Jest tutorial.
Test using LambdaTest cloud Selenium Grid - Run your Jest testing script over LambdaTest cloud-based platform and leverage parallel testing to help trim down your test execution time.
Snapshot Testing for React Front Ends - Capture screenshots of your react based web-application and compare them automatically for visual anomalies with the help of Jest tutorial.
Bonus: Import ES modules with Jest - ES modules are also known as ECMAScript modules. Learn how to best use them by importing in your Jest testing scripts.
Jest vs Mocha vs Jasmine - Learn the key differences between the most popular JavaScript-based testing frameworks i.e. Jest, Mocha, and Jasmine.
Jest FAQs(Frequently Asked Questions) - Explore the most commonly asked questions around Jest framework, with their answers.