Jest

Jest adds JSDOM v27 support and includes bug fixes such as exporting the TransformerConfig interface and improving TS loader handling in jest.config.ts.

This release fixes the unstable_mockModule handling of node-prefixed core modules.

Fixed snapshot header regexp in jest-snapshot-utils to work with newline characters across OSes.

This release fixes a deprecated goo.gl snapshot warning issue on Windows.

This release adds configurable GC aggressiveness, reduces redundant ReferenceError messages, improves failure reporting for onlyFailures mode, and fixes several snapshot, concurrency, and import path issues.

This patch release fixes two issues: it hardens deepCyclicCopyObject in jest-matcher-utils and makes the garbage collection protection property writable.

This release adds the new `defaultAsyncResolver`, fixes builtin module resolution and globals cleanup handling, and deprecates the `jest-repl` package.

Jest 30 is a substantial major release after a three-year gap, introducing numerous features like new matchers, improved configuration loading for TypeScript modules (mts/cts), and significant internal upgrades to JSDOM and fake timers. Users must consult the migration guide due to several breaking API changes.

Jest v30.0.0-beta.4 introduces a runtime improvement by switching to `compileFunction` over `new Script`.

Jest 30 drops Node 16 support, updates jsdom to v26, mitigates memory leaks, and introduces a new ArrayOf matcher while fixing numerous bugs.

Jest v30.0.0-alpha.7 adds new CLI and runtime features, upgrades key dependencies, and includes several bug fixes, while also introducing breaking changes to fake‑timer handling and config option types.