test: make WeakReference tests robust

Previously we assume that the objects are GC'ed after one
global.gc() returns, which is not necessarily always the case. Use
gcUntil() to run GC multiple times if they are not GC'ed in the
first time around.

PR-URL: https://github.com/nodejs/node/pull/49053
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

test/fixtures/snapshot/weak-reference-gc.js

@@ -5,16 +5,27 @@ const { WeakReference } = internalBinding('util');
 const {
   setDeserializeMainFunction
 } = require('v8').startupSnapshot
-const assert = require('assert');
 
 let obj = { hello: 'world' };
 const ref = new WeakReference(obj);
+let gcCount = 0;
+let maxGC = 10;
+
+function run() {
+  globalThis.gc();
+  setImmediate(() => {
+    gcCount++;
+    if (ref.get() === undefined) {
+      return;
+    } else if (gcCount < maxGC) {
+      run();
+    } else {
+      throw new Error(`Reference is still around after ${maxGC} GC`);
+    }
+  });
+}
 
 setDeserializeMainFunction(() => {
   obj = null;
-  globalThis.gc();
-
-  setImmediate(() => {
-    assert.strictEqual(ref.get(), undefined);
-  });
+  run();
 });

test/parallel/test-domain-async-id-map-leak.js

@@ -13,6 +13,8 @@ const isEnumerable = Function.call.bind(Object.prototype.propertyIsEnumerable);
 // See: https://github.com/nodejs/node/issues/23862
 
 let d = domain.create();
+let resourceGCed = false; let domainGCed = false; let
+  emitterGCed = false;
 d.run(() => {
   const resource = new async_hooks.AsyncResource('TestResource');
   const emitter = new EventEmitter();
@@ -30,10 +32,17 @@ d.run(() => {
   // emitter → resource → async id ⇒ domain → emitter.
   // Make sure that all of these objects are released:
 
-  onGC(resource, { ongc: common.mustCall() });
-  onGC(d, { ongc: common.mustCall() });
-  onGC(emitter, { ongc: common.mustCall() });
+  onGC(resource, { ongc: common.mustCall(() => { resourceGCed = true; }) });
+  onGC(d, { ongc: common.mustCall(() => { domainGCed = true; }) });
+  onGC(emitter, { ongc: common.mustCall(() => { emitterGCed = true; }) });
 });
 
 d = null;
-global.gc();
+
+async function main() {
+  await common.gcUntil(
+    'All objects garbage collected',
+    () => resourceGCed && domainGCed && emitterGCed);
+}
+
+main();

test/parallel/test-internal-util-weakreference.js

@@ -1,6 +1,6 @@
 // Flags: --expose-internals --expose-gc
 'use strict';
-require('../common');
+const common = require('../common');
 const assert = require('assert');
 const { internalBinding } = require('internal/test/binding');
 const { WeakReference } = internalBinding('util');
@@ -9,9 +9,11 @@ let obj = { hello: 'world' };
 const ref = new WeakReference(obj);
 assert.strictEqual(ref.get(), obj);
 
-setImmediate(() => {
+async function main() {
   obj = null;
-  global.gc();
+  await common.gcUntil(
+    'Reference is garbage collected',
+    () => ref.get() === undefined);
+}
 
-  assert.strictEqual(ref.get(), undefined);
-});
+main();