jest 19.0.0

• Breaking Change: Added a version for snapshots.
• Breaking Change: Removed the mocksPattern configuration option, it never worked correctly.
• Breaking Change: Renamed testPathDirs to roots to avoid confusion when configuring Jest.
• Breaking Change: Updated printing of React elements to cause fewer changes when props change.
• Breaking Change: Updated snapshot format to properly escape data.
• Fixed --color to be recognized correctly again.
• Fixed babel-plugin-jest-hoist to work properly with type annotations in tests.
• Fixed behavior for console.log calls and fixed a memory leak (#2539).
• Fixed cache directory path for Jest to avoid ENAMETOOLONG errors.
• Fixed change events to be emitted in jest-haste-map's watch mode. This fixes issues with Jest's new watch mode and react-native-packager.
• Fixed cli arguments to be used when loading the config from file, they were previously ignored.
• Fixed Jest to load json files that include a BOM.
• Fixed Jest to throw errors instead of ignoring invalid cli options.
• Fixed mocking behavior for virtual modules.
• Fixed mocking behavior with transitive dependencies.
• Fixed support for asymmetric matchers in toMatchObject.
• Fixed test interruption and --bail behavior.
• Fixed watch mode to clean up worker processes when a test run gets interrupted.
• Fixed whitespace to be highlighted in snapshots and assertion errors.
• Improved babel-jest plugin: babel is loaded lazily, istanbul comments are only added when coverage is used.
• Improved error for invalid transform config.
• Improved moduleNameMapper to not overwrite mocks when many patterns map to the same file.
• Improved printing of skipped tests in verbose mode.
• Improved resolution code in jest-resolve.
• Improved to only show patch marks in assertion errors when the comparison results in large objects.
• New --collectCoverageFrom cli argument.
• New --coverageDirectory cli argument.
• New expect.addSnapshotSerializer to add custom snapshot serializers for tests.
• New jest.spyOn.
• New testMatch configuration option that accepts glob patterns.
• New eslint-plugin-jest with no-disabled-tests, no-focuses-tests and no-identical-title rules and default configuration and globals.
• New expect.stringContaining asymmetric matcher.
• New feature to make manual mocks with nested folders work. For example __mocks__/react-native/Library/Text.js will now work as expected.
• New feature to re-run tests through the notification when using --notify.
• New jest-phabricator package to integrate Jest code coverage in phabriactor.
• New jest-validate package to improve configuration errors, help with suggestions of correct configuration and to be adopted in other libraries.
• New pretty-printing for asymmetric matchers.
• New RSS feed for Jest's blog.
• New way to provide a reducer to extract haste module ids.
• New website, new documentation, new color scheme and new homepage.
• Rewritten watch mode for instant feedback, better code quality and to build new features on top of it (#2362).

jest 18.0.0

See https://jestjs.io/blog/2016/12/15/2016-in-jest

• The testResultsProcessor function is now required to return the modified results.
• Removed pit and mockImpl. Use it or mockImplementation instead.
• Fixed re-running tests when --bail is used together with --watch.
• pretty-format is now merged into Jest.
• require('v8') now works properly in a test context.
• Jest now clears the entire scrollback in watch mode.
• Added expect.any, expect.anything, expect.objectContaining, expect.arrayContaining, expect.stringMatching.
• Properly resolve snapshotSerializers, setupFiles, transform, testRunner and testResultsProcessor instead of using path.resolve.
• --testResultsProcessor is now exposed through the cli.
• Renamed --jsonOutputFile to --outputFile.
• Added jest-editor-support for vscode and Nuclide integration.
• Fixed test.concurrent unhandled promise rejections.
• The Jest website is now auto-deployed when merging into main.
• Updated testRegex to include test.js and spec.js files.
• Fixes for babel-plugin-jest-hoist when using jest.mock with three arguments.
• The JSON global in jest-environment-node now comes from the vm context instead of the parent context.
• Jest does not print stack traces from babel any longer.
• Fake timers are reset when FakeTimers.useTimers() is called.
• Usage of Jest in watch mode can be hidden through JEST_HIDE_USAGE.
• Added expect.assertions(number) which will ensure that a specified amount of assertions is made in one test.
• Added .toMatchSnapshot(?string) feature to give snapshots a name.
• Escape regex in snapshots.
• jest-react-native was deprecated and now forwards react-native.
• Added .toMatchObject matcher.
• Further improve printing of large objects.
• Fixed NaN% Failed in the OS notification when using --notify.
• The first test run without cached timings will now use separate processes instead of running in band.
• Added .toHaveProperty matcher.
• Fixed Map/Set comparisons.
• test.concurrent now works with --testNamePattern.

jest 17.0.2

• Fixed performance regression in module resolution.

jest 16.0.0

• Previously failed tests are now always run first.
• A new concurrent reporter shows currently running tests, a test summary, a progress bar and estimated remaining time if possible.
• Improved CLI colors.
• jest <pattern> is now case-insensitive.
• Added it.only, it.skip, test.only, test.skip and xtest.
• Added --testNamePattern=pattern or -t <pattern> to run individual tests in test files.
• Jest now warns for duplicate mock files.
• Pressing a, o, p, q or enter while tests are running in the watch mode, the test run will be interrupted.
• --bail now works together with --watch.
• Added test.concurrent for concurrent async tests.
• Jest now automatically considers files and tests with the .jsx extension.
• Added jest.clearAllMocks to clear all mocks manually.
• Rewrote Jest's snapshot implementation. jest-snapshot can now be more easily integrated into other test runners and used in other projects.
• This requires most snapshots to be updated when upgrading Jest.
• Objects and Arrays in snapshots are now printed with a trailing comma.
• Function names are not printed in snapshots any longer to reduce issues with code coverage instrumentation and different Node versions.
• Snapshots are now sorted using natural sort order.
• Snapshots are not marked as obsolete any longer when using fit or when an error is thrown in a test.
• Finished migration of Jasmine matchers to the new Jest matchers.
• Pretty print toHaveBeenLastCalledWith, toHaveBeenCalledWith, lastCalledWith and toBeCalledWith failure messages.
• Added toBeInstanceOf matcher.
• Added toContainEqual matcher.
• Added toThrowErrorMatchingSnapshot matcher.
• Improved moduleNameMapper resolution.
• Module registry fixes.
• Fixed invocation of the setupTestFrameworkScriptFile script to make it easier to use chai together with Jest.
• Removed react-native special case in Jest's configuration.
• Added --findRelatedTests <fileA> <fileB> cli option to run tests related to the specified files.
• Added jest.deepUnmock to babel-plugin-jest-hoist.
• Added jest.runTimersToTime which is useful together with fake timers.
• Improved automated mocks for ES modules compiled with babel.

jest 15.0.0

• See https://jestjs.io/blog/2016/09/01/jest-15
• Jest by default now also recognizes files ending in .spec.js and .test.js as test files.
• Completely replaced most Jasmine matchers with new Jest matchers.
• Rewrote Jest's CLI output for test failures and summaries.
• Added --env option to override the default test environment.
• Disabled automocking, fake timers and resetting the module registry by default.
• Added --watchAll, made --watch interactive and added the ability to update snapshots and select test patterns in watch mode.
• Jest uses verbose mode when running a single test file.
• Console messages are now buffered and printed along with the test results.
• Fix testEnvironment resolution to prefer jest-environment-{name} instead of {name} only. This prevents a module collision when using jsdom as test environment.
• moduleNameMapper now uses a resolution algorithm.
• Improved performance for small test runs.
• Improved API documentation.
• Jest now works properly with directories that have special characters in them.
• Improvements to Jest's own test infra by merging integration and unit tests. Code coverage is now collected for Jest.
• Added global.global to the node environment.
• Fixed babel-jest-plugin-hoist issues with functions called mock.
• Improved jest-react-native preset with mocks for ListView, TextInput, ActivityIndicator and ScrollView.
• Added collectCoverageFrom to collect code coverage from untested files.
• Rewritten code coverage support.