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diff --git a/devtools/shared/test-helpers/browser_allocation_tracker.js b/devtools/shared/test-helpers/browser_allocation_tracker.js
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+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Load the tracker in a dedicated loader using invisibleToDebugger and freshCompartment
+// so that it can inspect any other module/compartment, even DevTools, chrome,
+// and this script!
+const { DevToolsLoader } = ChromeUtils.importESModule(
+ "resource://devtools/shared/loader/Loader.sys.mjs"
+);
+const loader = new DevToolsLoader({
+ invisibleToDebugger: true,
+ freshCompartment: true,
+});
+const { allocationTracker } = loader.require(
+ "chrome://mochitests/content/browser/devtools/shared/test-helpers/allocation-tracker"
+);
+const TrackedObjects = loader.require(
+ "resource://devtools/shared/test-helpers/tracked-objects.sys.mjs"
+);
+
+// This test record multiple times complete heap snapshot,
+// so that it can take a little bit to complete.
+requestLongerTimeout(2);
+
+add_task(async function () {
+ // Use a sandbox to allocate test javascript object in order to avoid any
+ // external noise
+ const global = Cu.Sandbox("http://example.com");
+
+ const tracker = allocationTracker({ watchGlobal: global });
+ const before = tracker.stillAllocatedObjects();
+
+ /* eslint-disable no-undef */
+ // This will allocation 1001 objects. The array and 1000 elements in it.
+ Cu.evalInSandbox(
+ "let list; new " +
+ function () {
+ list = [];
+ for (let i = 0; i < 1000; i++) {
+ list.push({});
+ }
+ },
+ global,
+ undefined,
+ "test-file.js",
+ 1,
+ /* enforceFilenameRestrictions */ false
+ );
+ /* eslint-enable no-undef */
+
+ const allocations = tracker.countAllocations();
+ ok(
+ allocations >= 1001,
+ `At least 1001 objects are reported as created (${allocations})`
+ );
+
+ // Uncomment this and comment the call to `countAllocations` to debug the allocations.
+ // The call to `countAllocations` will reset the allocation record.
+ // tracker.logAllocationSites();
+
+ const afterCreation = tracker.stillAllocatedObjects();
+ is(
+ afterCreation.objectsWithStack - before.objectsWithStack,
+ 1001,
+ "We got exactly the expected number of objects recorded with an allocation site"
+ );
+ ok(
+ afterCreation.objectsWithStack > before.objectsWithStack,
+ "We got some random number of objects without an allocation site"
+ );
+
+ Cu.evalInSandbox(
+ "list = null;",
+ global,
+ undefined,
+ "test-file.js",
+ 7,
+ /* enforceFilenameRestrictions */ false
+ );
+
+ Cu.forceGC();
+ Cu.forceCC();
+
+ const afterGC = tracker.stillAllocatedObjects();
+ is(
+ afterCreation.objectsWithStack - afterGC.objectsWithStack,
+ 1001,
+ "All the expected objects were reported freed in the count with allocation sites"
+ );
+ ok(
+ afterGC.objectsWithoutStack < afterCreation.objectsWithoutStack,
+ "And we released some random number of objects without an allocation site"
+ );
+
+ tracker.stop();
+});
+
+add_task(async function () {
+ const leaked = {};
+ TrackedObjects.track(leaked);
+ let transient = {};
+ TrackedObjects.track(transient);
+
+ is(TrackedObjects.getAllNodeIds().length, 2, "The two objects are reported");
+
+ info("Free the transient object");
+ transient = null;
+ Cu.forceGC();
+
+ is(
+ TrackedObjects.getAllNodeIds().length,
+ 1,
+ "We now only have the leaked object"
+ );
+ TrackedObjects.clear();
+});
+
+add_task(async function () {
+ info("Test start and stop recording without any debug mode");
+ const tracker = allocationTracker({ watchDevToolsGlobals: true });
+ await tracker.startRecordingAllocations();
+ await tracker.stopRecordingAllocations();
+ tracker.stop();
+});
+
+add_task(async function () {
+ info("Test start and stop recording with 'allocations' debug mode");
+ const tracker = allocationTracker({ watchDevToolsGlobals: true });
+ await tracker.startRecordingAllocations("allocations");
+ await tracker.stopRecordingAllocations("allocations");
+ tracker.stop();
+});
+
+add_task(async function () {
+ info("Test start and stop recording with 'leaks' debug mode");
+ const tracker = allocationTracker({ watchDevToolsGlobals: true });
+ await tracker.startRecordingAllocations("leaks");
+ await tracker.stopRecordingAllocations("leaks");
+ tracker.stop();
+});
+
+add_task(async function () {
+ info("Test start and stop recording with tracked objects");
+
+ const leaked = {};
+ TrackedObjects.track(leaked);
+
+ const tracker = allocationTracker({ watchAllGlobals: true });
+ await tracker.startRecordingAllocations();
+ await tracker.stopRecordingAllocations();
+ tracker.stop();
+
+ TrackedObjects.clear();
+});
+
+add_task(async function () {
+ info("Test start and stop recording with tracked objects");
+
+ const sandbox = Cu.Sandbox(window);
+ const tracker = allocationTracker({ watchGlobal: sandbox });
+ await tracker.startRecordingAllocations("leaks");
+
+ Cu.evalInSandbox("this.foo = {};", sandbox, null, "sandbox.js", 1);
+
+ const record = await tracker.stopRecordingAllocations("leaks");
+ is(
+ record.objectsWithStack,
+ 1,
+ "We get only one leaked objects, the foo object of the sandbox."
+ );
+ ok(
+ record.objectsWithoutStack > 10,
+ "We get an handful of objects without stacks. Most likely created by Memory API itself."
+ );
+
+ is(
+ record.leaks.length,
+ 2,
+ "We get the one leak and the objects with missing stacks"
+ );
+ is(
+ record.leaks[0].src,
+ "UNKNOWN",
+ "First item is the objects with missing stacks"
+ );
+ // In theory the two following values should be equal,
+ // but they aren't always because of some dark matter around objects with missing stacks.
+ // `count` is computed out of `takeCensus`, while `objectsWithoutStack` uses `drainAllocationsLog`
+ // While the first go through the current GC graph, the second is a record of allocations over time,
+ // this probably explain why there is some subtle difference
+ ok(
+ record.leaks[0].count <= record.objectsWithoutStack,
+ "For now, the leak report intermittently assume there is less leaked objects than the summary"
+ );
+ is(record.leaks[1].src, "sandbox.js", "Second item if about our 'foo' leak");
+ is(record.leaks[1].count, 1, "We leak one object on this file");
+ is(record.leaks[1].lines.length, 1, "We leak from only one line");
+ is(record.leaks[1].lines[0], "1: 1", "On first line, we leak one object");
+ tracker.stop();
+
+ TrackedObjects.clear();
+});
+
+add_task(async function () {
+ info("Test that transient globals are not leaked");
+
+ const tracker = allocationTracker({ watchAllGlobals: true });
+
+ let sandboxBefore = Cu.Sandbox(window);
+ // We need to allocate at least one object from the global to reproduce the leak
+ Cu.evalInSandbox(
+ "this.foo = {};",
+ sandboxBefore,
+ null,
+ "sandbox-before.js",
+ 1
+ );
+ const weakBefore = Cu.getWeakReference(sandboxBefore);
+ sandboxBefore = null;
+
+ await tracker.startRecordingAllocations();
+
+ ok(
+ !weakBefore.get(),
+ "Sandbox created before the record should have been freed by GCs done by startRecordingAllocations"
+ );
+
+ let sandboxDuring = Cu.Sandbox(window);
+ // We need to allocate at least one object from the global to reproduce the leak
+ Cu.evalInSandbox(
+ "this.bar = {};",
+ sandboxDuring,
+ null,
+ "sandbox-during.js",
+ 1
+ );
+ const weakDuring = Cu.getWeakReference(sandboxDuring);
+ sandboxDuring = null;
+
+ await tracker.stopRecordingAllocations();
+
+ ok(
+ !weakDuring.get(),
+ "Sandbox should have been freed by GCs done by stopRecordingAllocations"
+ );
+
+ tracker.stop();
+});