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

29.7.0

Features

• [create-jest] Add npm init / yarn create initialiser for Jest projects (#14465)
• [jest-validate] Allow deprecation warnings for unknown options (#14499)

Fixes

• [jest-resolver] Replace unmatched capture groups in moduleNameMapper with empty string instead of undefined (#14507)
• [jest-snapshot] Allow for strings as well as template literals in inline snapshots (#14465)
• [@jest/test-sequencer] Calculate test runtime if perStats.duration is missing (#14473)

Performance

• [@jest/create-cache-key-function] Cache access of NODE_ENV and BABEL_ENV (#14455)

Chore & Maintenance

• [jest-cli] Move internal config initialisation logic to the create-jest package (#14465)