jest-leak-detector

jest-leak-detector

Module for verifying whether an object has been garbage collected or not.

Internally creates a weak reference to the object, and forces garbage collection to happen. If the reference is gone, it meant no one else was pointing to the object.

Example

(async function () {
  let reference = {};
  let isLeaking;

  const detector = new LeakDetector(reference);

  // Reference is held in memory.
  isLeaking = await detector.isLeaking();
  console.log(isLeaking); // true

  // We destroy the only reference to the object.
  reference = null;

  // Reference is gone.
  isLeaking = await detector.isLeaking();
  console.log(isLeaking); // false
})();

Changelog

29.6.0

Features

• [jest-circus, jest-snapshot] Add support for snapshot matchers in concurrent tests (#14139)
• [jest-cli] Include type definitions to generated config files (#14078)
• [jest-snapshot] Support arrays as property matchers (#14025)
• [jest-core, jest-circus, jest-reporter, jest-runner] Added support for reporting about start individual test cases using jest-circus (#14174)

Fixes

• [jest-circus] Prevent false test failures caused by promise rejections handled asynchronously (#14110)
• [jest-config] Handle frozen config object (#14054)
• [jest-config] Allow coverageDirectory and collectCoverageFrom in project config (#14180)
• [jest-core] Always use workers in watch mode to avoid crashes (#14059).
• [jest-environment-jsdom, jest-environment-node] Fix assignment of customExportConditions via testEnvironmentOptions when custom env subclass defines a default value (#13989)
• [jest-matcher-utils] Fix copying value of inherited getters (#14007)
• [jest-mock] Tweak typings to allow jest.replaceProperty() replace methods (#14008)
• [jest-mock] Improve user input validation and error messages of spyOn and replaceProperty methods (#14087)
• [jest-runtime] Bind jest.isolateModulesAsync to this (#14083)
• [jest-runtime] Forward wrapperLength to the Script constructor as columnOffset for accurate debugging (#14148)
• [jest-runtime] Guard _isMockFunction access with in (#14188)
• [jest-snapshot] Fix a potential bug when not using prettier and improve performance (#14036)
• [@jest/transform] Do not instrument .json modules (#14048)
• [jest-worker] Restart a shut down worker before sending it a task (#14015)

Chore & Maintenance

• [*] Update semver dependency to get vulnerability fix (#14262)
• [docs] Updated documentation for the --runTestsByPath CLI command (#14004)
• [docs] Updated documentation regarding the synchronous fallback when asynchronous code transforms are unavailable (#14056)
• [docs] Update jest statistics of use and downloads in website Index.