babel-jest

New --projects option to run one instance of Jest in multiple projects at the same time.

New multi project runner

New --listTests flag.

New --showConfig flag.

New promise support for all expect matchers through .resolves and .rejects.

New expect.hasAssertions() function similar to expect.assertions().

New this.equals function exposed to custom matchers.

New valid-expect lint rule in eslint-plugin-jest.

New HtmlElement pretty-format plugin.

New Immutable pretty-format plugins.

New test environment per file setting through @jest-environment in the docblock.

New feature that allows every configuration option to be set from the command line.

New feature to add custom reporters to Jest through reporters in the configuration.

New feature to add expected and actual values to AssertionError.

New feature to map code coverage from transformers.

New feature to run untested code coverage in parallel.

New option to define a custom resolver.

New printing support for text and comment nodes in html pretty-format.

New snapshot testing FAQ

New support for custom platforms on jest-haste-map.

New support for mocking native async methods.

New guide on how to use Jest with any JavaScript framework.

New translation system for the Jest website.

New collapsing watch mode usage prompt after first run.

Forked Jasmine 2.5 into Jest's own test runner and rewrote large parts of Jasmine.

Jest does not write new snapshots by default on CI.

Moved the typescript parser from jest-editor-support into a separate jest-test-typescript-parser package.

Replaced auto-loading of babel-polyfill with only regenerator-runtime, fixes a major memory leak.

Fixed babel-jest to look up the babel field in package.json as a fallback.

Fixed jest-editor-support's parser to not crash on incomplete ASTs.

Fixed jest-resolve to use is-builtin-module instead of resolve.isCore.

Fixed jest-snapshot to normalize line endings in the serialize function.

Fixed behavior of --silent flag.

Fixed bug with watchers on macOS causing test to crash.

Fixed CLI notify option not taking precedence over config option.

Fixed detection of the npm client in SummaryReporter to support Yarn.

Fixed done.fail not passing arguments

Fixed fake timers to restore after resetting mocks.

Fixed handling of babylon's parser options in jest-editor-support.

Fixed Jest to properly cache transform results.

Fixed Jest to use human-readable colors for Jest's own snapshots.

Fixed jest-config to use UID for default cache folder. (#3380),

Fixed jest-runtime to expose inner error when it fails to write to the cache.

Fixed lifecycle hooks to make afterAll hooks operate the same as afterEach.

Fixed pretty-format to run plugins before serializing nested basic values.

Fixed return value of mocks so they can explicitly be set to return undefined.

Fixed runner to run tests associated with snapshots when the snapshot changes.

Fixed snapshot serializer require, restructured pretty-format.

Fixed support for Babel 7 in babel-jest.

Fixed testMatch to find tests in .folders.

Fixed testNamePattern and testPathPattern to work better together.

Fixed to show reject reason when expecting resolve.

Fixed toHaveProperty() to use hasOwnProperty from Object

Fixed watch mode's screen clearing.

Improved and consolidated Jest's configuration file resolution.

Improved documentation throughout the Jest website.

Improved documentation to explicitly mention that snapshots must be reviewed.

Improved documentation to make it clear CRA users don't need to add dependencies.

Improved eslint-plugin-jest's handling of expect.

Improved flow-coverage, eslint rules and test coverage within the Jest repository.

Improved printing of expect.assertions error.

Improved Windows test coverage of Jest.

Refactored configs & transform

Refactored reporters to pass individual Tests to reporters.

Refactored TestRunner

Refactored watch mode prompts.

Deleted jest-file-exists.

Removed Config type.

Removed all usage of jest-file-exists.

Adopted prettier on the Jest codebase.