jest-watcher
Advanced tools
The jest-watcher package is a part of the Jest ecosystem and is used to implement custom watch plugins for Jest. It provides an API to create plugins that can hook into Jest's watch mode, allowing developers to add custom watch behaviors to their test suites.
Custom Watch Plugins
This feature allows developers to create custom watch plugins that can react to file changes, determine if a test suite should run, and more. The code sample shows a basic structure of a custom watch plugin.
class MyCustomPlugin {
apply(jestHooks) {
jestHooks.onFileChange(({ projects }) => {
console.log('Files changed:', projects[0].changedFiles);
});
jestHooks.shouldRunTestSuite(() => true);
}
}
module.exports = MyCustomPlugin;Interactive Watch Plugins
This feature allows the creation of interactive watch plugins that can provide custom interactive CLI interfaces during Jest's watch mode. The code sample demonstrates how to implement an interactive behavior that filters tests based on a pattern.
class MyInteractivePlugin {
run(globalConfig, updateConfigAndRun) {
// Implement interactive behavior here
updateConfigAndRun({
testNamePattern: 'pattern to filter tests'
});
return Promise.resolve();
}
}
module.exports = MyInteractivePlugin;Mocha-watch is a watch mode for Mocha testing framework. It provides similar functionality to jest-watcher by re-running tests when file changes are detected. However, it is tailored for Mocha and does not offer the same plugin API for extending watch behavior.
Karma is a test runner that works with multiple testing frameworks like Jasmine, Mocha, and QUnit. It can watch files and re-run tests on changes, similar to jest-watcher. Karma is more of a full-fledged test runner with a focus on running tests in different browsers, whereas jest-watcher is specifically for creating watch plugins in Jest.
AVA is a test runner with built-in watch mode functionality. It automatically re-runs tests when it detects changes. AVA's watch mode is not plugin-based like jest-watcher, but it offers a simple and fast out-of-the-box solution for watching tests without the need for additional configuration.
24.9.0
[expect] Highlight substring differences when matcher fails, part 1 (#8448)[expect] Highlight substring differences when matcher fails, part 2 (#8528)[expect] Improve report when mock-spy matcher fails, part 1 (#8640)[expect] Improve report when mock-spy matcher fails, part 2 (#8649)[expect] Improve report when mock-spy matcher fails, part 3 (#8697)[expect] Improve report when mock-spy matcher fails, part 4 (#8710)[expect] Throw matcher error when received cannot be jasmine spy (#8747)[expect] Improve report when negative CalledWith assertion fails (#8755)[expect] Improve report when positive CalledWith assertion fails (#8771)[expect] Display equal values for ReturnedWith similar to CalledWith (#8791)[expect, jest-snapshot] Change color from green for some args in matcher hints (#8812)[jest-snapshot] Highlight substring differences when matcher fails, part 3 (#8569)[jest-core] Improve report when snapshots are obsolete (#8665)[jest-cli] Improve chai support (with detailed output, to match jest exceptions) (#8454)[*] Manage the global timeout with --testTimeout command line argument. (#8456)[pretty-format] Render custom displayName of memoized components (#8546)[jest-validate] Allow maxWorkers as part of the jest.config.js (#8565)[jest-runtime] Allow passing configuration objects to transformers (#7288)[@jest/core, @jest/test-sequencer] Support async sort in custom testSequencer (#8642)[jest-runtime, @jest/fake-timers] Add jest.advanceTimersToNextTimer (#8713)[@jest-transform] Extract transforming require logic within jest-core into @jest-transform (#8756)[jest-matcher-utils] Add color options to matcherHint (#8795)[jest-circus/jest-jasmine2] Give clearer output for Node assert errors (#8792)[jest-runner] Export all types in the type signature of jest-runner (#8825)[jest-cli] Detect side-effect only imports when running --onlyChanged or --changedSince (#8670)[jest-cli] Allow --maxWorkers to work with % input again (#8565)[babel-plugin-jest-hoist] Expand list of whitelisted globals in global mocks (#8429)[jest-core] Make watch plugin initialization errors look nice (#8422)[jest-snapshot] Prevent inline snapshots from drifting when inline snapshots are updated (#8492)[jest-haste-map] Don't throw on missing mapper in Node crawler (#8558)[jest-core] Fix incorrect passWithNoTests warning (#8595)[jest-snapshots] Fix test retries that contain snapshots (#8629)[jest-mock] Fix incorrect assignments when restoring mocks in instances where they originally didn't exist (#8631)[expect] Fix stack overflow when matching objects with circular references (#8687)[jest-haste-map] Workaround a node >=12.5.0 bug that causes the process not to exit after tests have completed and cancerous memory growth (#8787)[docs] Replace FlowType with TypeScript in CONTRIBUTING.MD code conventions[jest-leak-detector] remove code repeat (#8438)[docs] Add example to jest.requireActual (#8482)[docs] Add example to jest.mock for mocking ES6 modules with the factory parameter (#8550)[docs] Add information about using jest.doMock with ES6 imports (#8573)[docs] Fix variable name in custom-matcher-api code example (#8582)[docs] Fix example used in custom environment docs (#8617)[docs] Updated react tutorial to refer to new package of react-testing-library (@testing-library/react) (#8753)[docs] Updated imports of react-testing-library to @testing-library/react in website (#8757)[jest-core] Add getVersion (moved from jest-cli) (#8706)[docs] Fix MockFunctions example that was using toContain instead of toContainEqual (#8765)[*] Make sure copyright header comment includes license (#8783)[*] Check copyright and license as one joined substring (#8815)[docs] Fix WatchPlugins jestHooks.shouldRunTestSuite example that receives an object (#8784)[*] Enforce LF line endings (#8809)[pretty-format] Delete obsolete link and simplify structure in README (#8824)[docs] Fix broken transform link on webpack page (#9155)FAQs
Delightful JavaScript Testing.
The npm package jest-watcher receives a total of 10,921,969 weekly downloads. As such, jest-watcher popularity was classified as popular.
We found that jest-watcher demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 5 open source maintainers collaborating on the project.
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