Skip to content

Commit

Permalink
feat(jest-leak-detector): use FinalizationRegistry when it exists to …
Browse files Browse the repository at this point in the history
…get rid of external dependency
  • Loading branch information
enrilzhou committed Jun 30, 2022
1 parent fef194f commit 61f3366
Show file tree
Hide file tree
Showing 2 changed files with 29 additions and 12 deletions.
2 changes: 2 additions & 0 deletions CHANGELOG.md
Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,8 @@

### Features

- `[jest-leak-detector]` Use native `FinalizationRegistry` when it exists to get rid of external C dependency ([#12973](https://github.com/facebook/jest/pull/12973))

### Fixes

-`[jest-runtime]` Avoid star type import from `@jest/globals` ([#12949](https://github.com/facebook/jest/pull/12949))
Expand Down
39 changes: 27 additions & 12 deletions packages/jest-leak-detector/src/index.ts
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
/// <reference lib="es2021.WeakRef" />

import {promisify} from 'util';
import {setFlagsFromString} from 'v8';
Expand All @@ -15,6 +16,7 @@ const tick = promisify(setImmediate);

export default class LeakDetector {
private _isReferenceBeingHeld: boolean;
private _finalizationRegistry?: FinalizationRegistry<undefined>;

constructor(value: unknown) {
if (isPrimitive(value)) {
Expand All @@ -26,23 +28,36 @@ export default class LeakDetector {
);
}

let weak: typeof import('weak-napi');
// TODO: Remove the `if` and `weak-napi` when we drop node 12, as v14 supports FinalizationRegistry
if (globalThis.FinalizationRegistry) {
// When `_finalizationRegistry` is GCed the callback we set will no longer be called,
// so we need to assign it to `this` to keep it referenced
this._finalizationRegistry = new FinalizationRegistry(() => {
this._isReferenceBeingHeld = false;
});

try {
// eslint-disable-next-line import/no-extraneous-dependencies
weak = require('weak-napi');
} catch (err: any) {
if (!err || err.code !== 'MODULE_NOT_FOUND') {
throw err;
this._finalizationRegistry.register(value as object, undefined);
} else {
let weak: typeof import('weak-napi');

try {
// eslint-disable-next-line import/no-extraneous-dependencies
weak = require('weak-napi');
} catch (err: any) {
if (!err || err.code !== 'MODULE_NOT_FOUND') {
throw err;
}

throw new Error(
'The leaking detection mechanism requires newer version of node that supports ' +
'FinalizationRegistry, update your node or install the "weak-napi" package' +
'which support current node version as a dependency on your main project.',
);
}

throw new Error(
'The leaking detection mechanism requires the "weak-napi" package to be installed and work. ' +
'Please install it as a dependency on your main project',
);
weak(value as object, () => (this._isReferenceBeingHeld = false));
}

weak(value as object, () => (this._isReferenceBeingHeld = false));
this._isReferenceBeingHeld = true;

// Ensure value is not leaked by the closure created by the "weak" callback.
Expand Down

0 comments on commit 61f3366

Please sign in to comment.