jest-haste-map

What is jest-haste-map?

The jest-haste-map npm package is a utility for building a Haste map, which is a mapping from module names to file paths. It is used by Jest to quickly resolve module dependencies for tests by keeping an in-memory map of all available modules. It can handle duplicate module names and provides a way to query the map for a specific module.

What are jest-haste-map's main functionalities?

Building a Haste Map

This code sample demonstrates how to create a new HasteMap instance with a configuration object, build the map, and then use it to get the module name for a specific file.

const HasteMap = require('jest-haste-map');
const config = {
  // These options are required:
  roots: ['/path/to/project'],
  extensions: ['js', 'json'],
  platforms: ['ios', 'android'],
  // You can provide additional options:
  computeSha1: true,
  // other options...
};
const hasteMap = new HasteMap(config);
hasteMap.build().then(map => {
  console.log(map.hasteFS.getModuleName('/path/to/project/file.js'));
});

Querying the Haste Map

This code sample shows how to query the built Haste map for the path of a module given its name, platform, and whether it supports the native platform.

hasteMap.build().then(map => {
  const modulePath = map.moduleMap.getModule('moduleName', 'platform', 'supportsNativePlatform');
  console.log(modulePath);
});

Other packages similar to jest-haste-map

metro

Metro is a JavaScript bundler for React Native applications. It includes a Haste map implementation similar to jest-haste-map, but it is tailored specifically for React Native and includes additional features for bundling and transforming code.

webpack

Webpack is a powerful module bundler for JavaScript applications. While it does not use a Haste map, it provides a similar functionality through its own resolution mechanism, which can handle complex dependency graphs and offers a wide range of plugins for different tasks.

browserify

Browserify is a tool for bundling JavaScript files for usage in the browser. Like webpack, it does not use a Haste map, but it allows developers to require modules in the browser by bundling up all dependencies. It's simpler than webpack and may be more suitable for smaller projects.

README

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Changelog

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.