@jest/transform

Features

• @jest/globals: New package so Jest's globals can be explicitly imported

• jest-core: Show coverage of sources related to tests in changed files

• jest-runtime: Populate require.cache

Fixes

• *: Use graceful-fs directly in every package instead of relying on fs being monkey patched

• expect: Prints the Symbol name into the error message with a custom asymmetric matcher

• jest-circus, jest-jasmine2: Support older version of jest-runtime (#9903 & #9842)

• @jest/environment: Make sure not to reference Jest types

• jest-message-util: Code frame printing should respect --noStackTrace flag

• jest-runtime: Support importing CJS from ESM using import statements

• jest-runtime: Support importing parallel dynamic imports

• jest-transform: Improve source map handling when instrumenting transformed code

Performance

• jest-resolve: Update resolve to a version using native realpath, which is faster than the default JS implementation

• jest-resolve: Pass custom cached realpath function to resolve

• jest-runtime: Add teardown method to clear any caches when tests complete

• jest-runtime: Do not pass files required internally through transformation when loading them

• jest-runtime: Use Maps instead of object literals as cache holders