1 files changed, 42 insertions, 0 deletions
diff --git a/js/xpconnect/tests/unit/test_onGarbageCollection-05.js b/js/xpconnect/tests/unit/test_onGarbageCollection-05.js
new file mode 100644
index 0000000000..e3b5e5fd9e
--- /dev/null
+++ b/js/xpconnect/tests/unit/test_onGarbageCollection-05.js
@@ -0,0 +1,42 @@
+// Test that the onGarbageCollection hook reports its gc cycle's number (aka the
+// major GC number) and that it is monotonically increasing.
+
+const root = newGlobal();
+const dbg = new Debugger();
+const wrappedRoot = dbg.addDebuggee(root)
+
+Services.prefs.setBoolPref("security.allow_eval_with_system_principal", true);
+registerCleanupFunction(() => {
+  Services.prefs.clearUserPref("security.allow_eval_with_system_principal");
+});
+
+function run_test() {
+  do_test_pending();
+
+  let numFired = 0;
+  let lastGCCycleNumber = undefined;
+
+  (function loop() {
+    if (numFired == 10) {
+      dbg.memory.onGarbageCollection = undefined;
+      dbg.enabled = false;
+      return void do_test_finished();
+    }
+
+    dbg.memory.onGarbageCollection = data => {
+      print("onGarbageCollection: " + uneval(data));
+
+      if (numFired != 0) {
+        equal(typeof lastGCCycleNumber, "number");
+        equal(data.gcCycleNumber - lastGCCycleNumber, 1);
+      }
+
+      numFired++;
+      lastGCCycleNumber = data.gcCycleNumber;
+
+      executeSoon(loop);
+    };
+
+    root.eval("gc(this)");
+  }());
+}