[js weak refs] Add simple cctests for JSWeakRefs

BUG=v8:8179

Change-Id: I8ef7d3b576db9e872ab527895f5ba3be4ba3f6ce
Reviewed-on: https://chromium-review.googlesource.com/c/1379881Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58304}

test/cctest/test-js-weak-refs.cc

@@ -5,8 +5,10 @@
 #include "src/handles-inl.h"
 #include "src/heap/factory-inl.h"
 #include "src/isolate.h"
+#include "src/objects/js-objects.h"
 #include "src/objects/js-weak-refs-inl.h"
 #include "test/cctest/cctest.h"
+#include "test/cctest/heap/heap-utils.h"
 
 namespace v8 {
 namespace internal {
@@ -29,6 +31,24 @@ Handle<JSWeakFactory> ConstructJSWeakFactory(Isolate* isolate) {
   return weak_factory;
 }
 
+Handle<JSWeakRef> ConstructJSWeakRef(Isolate* isolate,
+                                     Handle<JSReceiver> target) {
+  Factory* factory = isolate->factory();
+  Handle<String> weak_ref_name = factory->WeakRef_string();
+  Handle<Object> global =
+      handle(isolate->native_context()->global_object(), isolate);
+  Handle<JSFunction> weak_ref_fun = Handle<JSFunction>::cast(
+      Object::GetProperty(isolate, global, weak_ref_name).ToHandleChecked());
+  auto weak_ref = Handle<JSWeakRef>::cast(
+      JSObject::New(weak_ref_fun, weak_ref_fun, Handle<AllocationSite>::null())
+          .ToHandleChecked());
+  weak_ref->set_target(*target);
+#ifdef VERIFY_HEAP
+  weak_ref->JSWeakRefVerify(isolate);
+#endif  // VERIFY_HEAP
+  return weak_ref;
+}
+
 Handle<JSWeakCell> MakeCell(Isolate* isolate, Handle<JSObject> js_object,
                             Handle<JSWeakFactory> weak_factory) {
   Handle<Map> weak_cell_map(isolate->native_context()->js_weak_cell_map(),
@@ -315,5 +335,142 @@ TEST(TestJSWeakCellClearPopped) {
   ClearWeakCell(weak_cell1, isolate);
 }
 
+TEST(TestJSWeakRef) {
+  FLAG_harmony_weak_refs = true;
+  CcTest::InitializeVM();
+  LocalContext context;
+
+  Isolate* isolate = CcTest::i_isolate();
+  HandleScope outer_scope(isolate);
+  Handle<JSWeakRef> weak_ref;
+  {
+    HandleScope inner_scope(isolate);
+
+    Handle<JSObject> js_object =
+        isolate->factory()->NewJSObject(isolate->object_function());
+    // This doesn't add the target into the KeepDuringJob set.
+    Handle<JSWeakRef> inner_weak_ref = ConstructJSWeakRef(isolate, js_object);
+
+    CcTest::CollectAllGarbage();
+    CHECK(!inner_weak_ref->target()->IsUndefined(isolate));
+
+    weak_ref = inner_scope.CloseAndEscape(inner_weak_ref);
+  }
+
+  CHECK(!weak_ref->target()->IsUndefined(isolate));
+
+  CcTest::CollectAllGarbage();
+
+  CHECK(weak_ref->target()->IsUndefined(isolate));
+}
+
+TEST(TestJSWeakRefIncrementalMarking) {
+  FLAG_harmony_weak_refs = true;
+  if (!FLAG_incremental_marking) {
+    return;
+  }
+  ManualGCScope manual_gc_scope;
+  CcTest::InitializeVM();
+  LocalContext context;
+
+  Isolate* isolate = CcTest::i_isolate();
+  Heap* heap = isolate->heap();
+  HandleScope outer_scope(isolate);
+  Handle<JSWeakRef> weak_ref;
+  {
+    HandleScope inner_scope(isolate);
+
+    Handle<JSObject> js_object =
+        isolate->factory()->NewJSObject(isolate->object_function());
+    // This doesn't add the target into the KeepDuringJob set.
+    Handle<JSWeakRef> inner_weak_ref = ConstructJSWeakRef(isolate, js_object);
+
+    heap::SimulateIncrementalMarking(heap, true);
+    CcTest::CollectAllGarbage();
+    CHECK(!inner_weak_ref->target()->IsUndefined(isolate));
+
+    weak_ref = inner_scope.CloseAndEscape(inner_weak_ref);
+  }
+
+  CHECK(!weak_ref->target()->IsUndefined(isolate));
+
+  heap::SimulateIncrementalMarking(heap, true);
+  CcTest::CollectAllGarbage();
+
+  CHECK(weak_ref->target()->IsUndefined(isolate));
+}
+
+TEST(TestJSWeakRefKeepDuringJob) {
+  FLAG_harmony_weak_refs = true;
+  CcTest::InitializeVM();
+  LocalContext context;
+
+  Isolate* isolate = CcTest::i_isolate();
+  Heap* heap = isolate->heap();
+  HandleScope outer_scope(isolate);
+  Handle<JSWeakRef> weak_ref;
+  {
+    HandleScope inner_scope(isolate);
+
+    Handle<JSObject> js_object =
+        isolate->factory()->NewJSObject(isolate->object_function());
+    Handle<JSWeakRef> inner_weak_ref = ConstructJSWeakRef(isolate, js_object);
+    heap->AddKeepDuringJobTarget(js_object);
+
+    weak_ref = inner_scope.CloseAndEscape(inner_weak_ref);
+  }
+
+  CHECK(!weak_ref->target()->IsUndefined(isolate));
+
+  CcTest::CollectAllGarbage();
+
+  CHECK(!weak_ref->target()->IsUndefined(isolate));
+
+  // Clears the KeepDuringJob set.
+  isolate->RunMicrotasks();
+  CcTest::CollectAllGarbage();
+
+  CHECK(weak_ref->target()->IsUndefined(isolate));
+}
+
+TEST(TestJSWeakRefKeepDuringJobIncrementalMarking) {
+  FLAG_harmony_weak_refs = true;
+  if (!FLAG_incremental_marking) {
+    return;
+  }
+  ManualGCScope manual_gc_scope;
+  CcTest::InitializeVM();
+  LocalContext context;
+
+  Isolate* isolate = CcTest::i_isolate();
+  Heap* heap = isolate->heap();
+  HandleScope outer_scope(isolate);
+  Handle<JSWeakRef> weak_ref;
+  {
+    HandleScope inner_scope(isolate);
+
+    Handle<JSObject> js_object =
+        isolate->factory()->NewJSObject(isolate->object_function());
+    Handle<JSWeakRef> inner_weak_ref = ConstructJSWeakRef(isolate, js_object);
+    heap->AddKeepDuringJobTarget(js_object);
+
+    weak_ref = inner_scope.CloseAndEscape(inner_weak_ref);
+  }
+
+  CHECK(!weak_ref->target()->IsUndefined(isolate));
+
+  heap::SimulateIncrementalMarking(heap, true);
+  CcTest::CollectAllGarbage();
+
+  CHECK(!weak_ref->target()->IsUndefined(isolate));
+
+  // Clears the KeepDuringJob set.
+  isolate->RunMicrotasks();
+  heap::SimulateIncrementalMarking(heap, true);
+  CcTest::CollectAllGarbage();
+
+  CHECK(weak_ref->target()->IsUndefined(isolate));
+}
+
 }  // namespace internal
 }  // namespace v8