Bug 1493237 - Use a test-only non-nsISupports wrapper cached WebIDL class in a weak map test r=bzbarsky

Differential Revision: https://phabricator.services.mozilla.com/D8134

--HG--
extra : moz-landing-system : lando

dom/bindings/moz.build

@@ -122,11 +122,11 @@ SOURCES += [
     'StructuredClone.cpp',
 ]
 
-# Tests for maplike and setlike require bindings to be built, which means they
-# must be included in libxul. This breaks the "no test classes are exported"
-# rule stated in the test/ directory, but it's the only way this will work.
-# Test classes are only built in debug mode, and all tests requiring use of
-# them are only run in debug mode.
+# Some tests, including those for for maplike and setlike, require bindings
+# to be built, which means they must be included in libxul. This breaks the
+# "no test classes are exported" rule stated in the test/ directory, but it's
+# the only way this will work. Test classes are only built in debug mode, and
+# all tests requiring use of them are only run in debug mode.
 if CONFIG['MOZ_DEBUG'] and CONFIG['ENABLE_TESTS']:
     EXPORTS.mozilla.dom += [
         "test/TestFunctions.h",
@@ -136,7 +136,8 @@ if CONFIG['MOZ_DEBUG'] and CONFIG['ENABLE_TESTS']:
         "test/TestInterfaceMaplike.h",
         "test/TestInterfaceMaplikeObject.h",
         "test/TestInterfaceSetlike.h",
-        "test/TestInterfaceSetlikeNode.h"
+        "test/TestInterfaceSetlikeNode.h",
+        "test/WrapperCachedNonISupportsTestInterface.h",
         ]
     UNIFIED_SOURCES += [
         "test/TestFunctions.cpp",
@@ -147,6 +148,7 @@ if CONFIG['MOZ_DEBUG'] and CONFIG['ENABLE_TESTS']:
         "test/TestInterfaceMaplikeObject.cpp",
         "test/TestInterfaceSetlike.cpp",
         "test/TestInterfaceSetlikeNode.cpp",
+        "test/WrapperCachedNonISupportsTestInterface.cpp",
         ]
 
 include('/ipc/chromium/chromium-config.mozbuild')

dom/bindings/test/TestFunctions.cpp

@@ -7,6 +7,7 @@
 #include "mozilla/dom/BindingUtils.h"
 #include "mozilla/dom/TestFunctions.h"
 #include "mozilla/dom/TestFunctionsBinding.h"
+#include "mozilla/dom/WrapperCachedNonISupportsTestInterface.h"
 #include "nsStringBuffer.h"
 #include "mozITestInterfaceJS.h"
 #include "nsComponentManagerUtils.h"
@@ -140,6 +141,15 @@ TestFunctions::ObjectFromAboutBlank(JSContext* aCx, JSObject* aObj)
   return doc->GetDocumentURI()->GetSpecOrDefault().EqualsLiteral("about:blank");
 }
 
+WrapperCachedNonISupportsTestInterface*
+TestFunctions::WrapperCachedNonISupportsObject()
+{
+  if (!mWrapperCachedNonISupportsTestInterface) {
+    mWrapperCachedNonISupportsTestInterface = new WrapperCachedNonISupportsTestInterface();
+  }
+  return mWrapperCachedNonISupportsTestInterface;
+}
+
 bool
 TestFunctions::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto,
                           JS::MutableHandle<JSObject*> aWrapper)

dom/bindings/test/TestFunctions.h

@@ -17,6 +17,7 @@ namespace dom {
 
 class Promise;
 class PromiseReturner;
+class WrapperCachedNonISupportsTestInterface;
 
 class TestFunctions : public NonRefcountedDOMObject {
 public:
@@ -51,10 +52,13 @@ public:
 
   static bool ObjectFromAboutBlank(JSContext* aCx, JSObject* aObj);
 
+  WrapperCachedNonISupportsTestInterface* WrapperCachedNonISupportsObject();
+
   bool WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto,
                   JS::MutableHandle<JSObject*> aWrapper);
 private:
   nsString mStringData;
+  RefPtr<WrapperCachedNonISupportsTestInterface> mWrapperCachedNonISupportsTestInterface;
 };
 
 } // namespace dom

dom/bindings/test/WrapperCachedNonISupportsTestInterface.cpp

@@ -0,0 +1,25 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/WrapperCachedNonISupportsTestInterface.h"
+#include "mozilla/dom/TestFunctionsBinding.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(WrapperCachedNonISupportsTestInterface, AddRef)
+NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(WrapperCachedNonISupportsTestInterface, Release)
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_0(WrapperCachedNonISupportsTestInterface)
+
+JSObject*
+WrapperCachedNonISupportsTestInterface::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return WrapperCachedNonISupportsTestInterface_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+} // namespace dom
+} // namespace mozilla

dom/bindings/test/WrapperCachedNonISupportsTestInterface.h

@@ -0,0 +1,44 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_WrapperCachedNonISupportsTestInterface_h
+#define mozilla_dom_WrapperCachedNonISupportsTestInterface_h
+
+#include "js/TypeDecls.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/ErrorResult.h"
+#include "mozilla/dom/BindingDeclarations.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsWrapperCache.h"
+
+
+namespace mozilla {
+namespace dom {
+
+class WrapperCachedNonISupportsTestInterface final : public nsWrapperCache
+{
+public:
+  NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(WrapperCachedNonISupportsTestInterface)
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(WrapperCachedNonISupportsTestInterface)
+
+public:
+  WrapperCachedNonISupportsTestInterface() {}
+
+protected:
+  ~WrapperCachedNonISupportsTestInterface() {}
+
+public:
+  nsISupports* GetParentObject() const {
+    return nullptr;
+  }
+
+  virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_WrapperCachedNonISupportsTestInterface_h

dom/webidl/TestFunctions.webidl

@@ -8,6 +8,10 @@
 
 callback PromiseReturner = Promise<any>();
 
+[Pref="dom.expose_test_interfaces"]
+interface WrapperCachedNonISupportsTestInterface {
+};
+
 [Pref="dom.expose_test_interfaces",
  Constructor]
 interface TestFunctions {
@@ -56,4 +60,11 @@ interface TestFunctions {
 
   // Testing for how default toJSON behaves.
   [Default] object toJSON();
+
+  // This returns a wrappercached non-ISupports object. While this will always
+  // return the same object, no optimization attributes like [Pure] should be
+  // used here because the object should not be held alive from JS by the
+  // bindings. This is needed to test wrapper preservation for weak map keys.
+  // See bug 1351501.
+  readonly attribute WrapperCachedNonISupportsTestInterface wrapperCachedNonISupportsObject;
 };

js/xpconnect/tests/mochitest/mochitest.ini

@@ -103,6 +103,7 @@ support-files =
 skip-if = (debug == false)
 [test_getweakmapkeys.html]
 [test_paris_weakmap_keys.html]
+skip-if = (debug == false)
 [test_nac.xhtml]
 [test_nukeContentWindow.html]
 [test_sameOriginPolicy.html]

js/xpconnect/tests/mochitest/test_paris_weakmap_keys.html

@@ -39,28 +39,21 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=777385
 
   make_live_map();
 
-
-  // CanvasGradient is a non-nsISupports wrapper cached class using WebIDL
-  // bindings. If we used it as a key in a weak map, then it should not be
-  // removed from the weak map as long as it remains alive.
-  let doc = new DOMParser().parseFromString("", "text/html");
-  let canv = doc.createElement("canvas");
-  let ctx = canv.getContext("2d");
+  let tf = new TestFunctions;
 
   let add_non_isupports2 = function () {
-    let grad = ctx.createLinearGradient(0, 0, 0, 0);
-    ctx.strokeStyle = grad;
+    let testKey = tf.wrapperCachedNonISupportsObject;
 
-    let gradFail = false;
+    let testFail = false;
     try {
-      live_map.set(grad, 23456);
+      live_map.set(testKey, 23456);
     } catch (e) {
-      gradFail = true;
+      testFail = true;
     }
 
-    ok(!gradFail, "Using a wrapper cached non-nsISupports class as a weak map key should not produce an exception.");
+    ok(!testFail, "Using a wrapper cached non-nsISupports class as a weak map key should not produce an exception.");
 
-    is(live_map.get(grad), 23456, "Live map should have live DOMPoint with right value before GC.");
+    is(live_map.get(testKey), 23456, "Live map should have wrapper cached non-nsISupports class right value before GC.");
   }
 
   add_non_isupports2();
@@ -74,20 +67,28 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=777385
     SpecialPowers.forceGC();
 
     is(SpecialPowers.nondeterministicGetWeakMapKeys(live_map).length, 2,
-       "Live nsISupports new DOM bindings wrappercached native weak map key should not be removed.");
+       "Live WebIDL bindings keys should not be removed from a weak map.");
 
-    is(live_map.get(get_div_style()), 12345, "Live map should have live style with right value after GC.");
-    is(live_map.get(ctx.strokeStyle), 23456, "Live map should have live gradient with right value after GC.");
+    is(live_map.get(get_div_style()), 12345, "Live weak map should have live style with right value after GC.");
+    is(live_map.get(tf.wrapperCachedNonISupportsObject), 23456,
+       "Live weak map should have live wrapper cached non-nsISupports class with right value after GC.");
 
     SimpleTest.finish();
   });
 
   }
+
+  SimpleTest.waitForExplicitFinish();
+
+  addLoadEvent(function() {
+    SpecialPowers.pushPrefEnv({set: [['dom.expose_test_interfaces', true]]},
+                              go);
+  });
   </script>
 </head>
 <div></div>
 <div id="mydivname"></div>
-<body onload="go()";>
+<body>
 <p id="display"></p>
 </body>
 </html>