testing js app

node_modules/jest-leak-detector/build/index.d.ts

@@ -0,0 +1,19 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * 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" />
+
+/// <reference lib="es2021.weakref" />
+declare class LeakDetector {
+  private _isReferenceBeingHeld;
+  private _finalizationRegistry?;
+  constructor(value: unknown);
+  isLeaking(): Promise<boolean>;
+  private _runGarbageCollector;
+}
+export default LeakDetector;
+
+export {};

node_modules/jest-leak-detector/build/index.js

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+'use strict';
+
+Object.defineProperty(exports, '__esModule', {
+  value: true
+});
+exports.default = void 0;
+
+function _util() {
+  const data = require('util');
+
+  _util = function () {
+    return data;
+  };
+
+  return data;
+}
+
+function _v() {
+  const data = require('v8');
+
+  _v = function () {
+    return data;
+  };
+
+  return data;
+}
+
+function _vm() {
+  const data = require('vm');
+
+  _vm = function () {
+    return data;
+  };
+
+  return data;
+}
+
+function _jestGetType() {
+  const data = require('jest-get-type');
+
+  _jestGetType = function () {
+    return data;
+  };
+
+  return data;
+}
+
+function _prettyFormat() {
+  const data = require('pretty-format');
+
+  _prettyFormat = function () {
+    return data;
+  };
+
+  return data;
+}
+
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * 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" />
+const tick = (0, _util().promisify)(setImmediate);
+
+class LeakDetector {
+  _isReferenceBeingHeld;
+  _finalizationRegistry;
+
+  constructor(value) {
+    if ((0, _jestGetType().isPrimitive)(value)) {
+      throw new TypeError(
+        [
+          'Primitives cannot leak memory.',
+          `You passed a ${typeof value}: <${(0, _prettyFormat().format)(
+            value
+          )}>`
+        ].join(' ')
+      );
+    } // 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;
+      });
+
+      this._finalizationRegistry.register(value, undefined);
+    } else {
+      let weak;
+
+      try {
+        // eslint-disable-next-line import/no-extraneous-dependencies
+        weak = require('weak-napi');
+      } catch (err) {
+        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.'
+        );
+      }
+
+      weak(value, () => (this._isReferenceBeingHeld = false));
+    }
+
+    this._isReferenceBeingHeld = true; // Ensure value is not leaked by the closure created by the "weak" callback.
+
+    value = null;
+  }
+
+  async isLeaking() {
+    this._runGarbageCollector(); // wait some ticks to allow GC to run properly, see https://github.com/nodejs/node/issues/34636#issuecomment-669366235
+
+    for (let i = 0; i < 10; i++) {
+      await tick();
+    }
+
+    return this._isReferenceBeingHeld;
+  }
+
+  _runGarbageCollector() {
+    // @ts-expect-error: not a function on `globalThis`
+    const isGarbageCollectorHidden = globalThis.gc == null; // GC is usually hidden, so we have to expose it before running.
+
+    (0, _v().setFlagsFromString)('--expose-gc');
+    (0, _vm().runInNewContext)('gc')(); // The GC was not initially exposed, so let's hide it again.
+
+    if (isGarbageCollectorHidden) {
+      (0, _v().setFlagsFromString)('--no-expose-gc');
+    }
+  }
+}
+
+exports.default = LeakDetector;