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

25.4.0

• [expect] Support async functions in toThrow (#9817)
• [jest-console] Add code frame to console.error and console.warn (#9741)
• [jest-runtime, jest-jasmine2, jest-circus] Experimental, limited ECMAScript Modules support (#9772 & #9842)

Fixes

• [expect] Restore support for passing functions to toHaveLength matcher (#9796)
• [jest-changed-files] --only-changed should include staged files (#9799)
• [jest-circus] Throw on nested test definitions (#9828)
• [jest-each] each will throw an error when called with too many arguments (#9818)
• [jest-runner] Don't print warning to stdout when using --json (#9843)

Chore & Maintenance

• [*] Do not generate TypeScript declaration source maps (#9822)
• [*] Transpile code for Node 8.3, not 8.0 (#9827)