Add m-esr52 at 52.6.0

9 files changed, 755 insertions, 0 deletions

diff --git a/devtools/shared/heapsnapshot/tests/gtest/DeserializedNodeUbiNodes.cpp b/devtools/shared/heapsnapshot/tests/gtest/DeserializedNodeUbiNodes.cpp
new file mode 100644
index 000000000..e236a0acf
--- /dev/null
+++ b/devtools/shared/heapsnapshot/tests/gtest/DeserializedNodeUbiNodes.cpp
@@ -0,0 +1,100 @@
+/* -*-  Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
+/* 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/. */
+
+// Test that the `JS::ubi::Node`s we create from
+// `mozilla::devtools::DeserializedNode` instances look and behave as we would
+// like.
+
+#include "DevTools.h"
+#include "js/TypeDecls.h"
+#include "mozilla/devtools/DeserializedNode.h"
+
+using testing::Field;
+using testing::ReturnRef;
+
+// A mock DeserializedNode for testing.
+struct MockDeserializedNode : public DeserializedNode
+{
+  MockDeserializedNode(NodeId id, const char16_t* typeName, uint64_t size)
+    : DeserializedNode(id, typeName, size)
+  { }
+
+  bool addEdge(DeserializedEdge&& edge)
+  {
+    return edges.append(Move(edge));
+  }
+
+  MOCK_METHOD1(getEdgeReferent, JS::ubi::Node(const DeserializedEdge&));
+};
+
+size_t fakeMallocSizeOf(const void*) {
+  EXPECT_TRUE(false);
+  MOZ_ASSERT_UNREACHABLE("fakeMallocSizeOf should never be called because "
+                         "DeserializedNodes report the deserialized size.");
+  return 0;
+}
+
+DEF_TEST(DeserializedNodeUbiNodes, {
+    const char16_t* typeName = u"TestTypeName";
+    const char* className = "MyObjectClassName";
+    const char* filename = "my-cool-filename.js";
+
+    NodeId id = uint64_t(1) << 33;
+    uint64_t size = uint64_t(1) << 60;
+    MockDeserializedNode mocked(id, typeName, size);
+    mocked.coarseType = JS::ubi::CoarseType::Script;
+    mocked.jsObjectClassName = className;
+    mocked.scriptFilename = filename;
+
+    DeserializedNode& deserialized = mocked;
+    JS::ubi::Node ubi(&deserialized);
+
+    // Test the ubi::Node accessors.
+
+    EXPECT_EQ(size, ubi.size(fakeMallocSizeOf));
+    EXPECT_EQ(typeName, ubi.typeName());
+    EXPECT_EQ(JS::ubi::CoarseType::Script, ubi.coarseType());
+    EXPECT_EQ(id, ubi.identifier());
+    EXPECT_FALSE(ubi.isLive());
+    EXPECT_EQ(ubi.jsObjectClassName(), className);
+    EXPECT_EQ(ubi.scriptFilename(), filename);
+
+    // Test the ubi::Node's edges.
+
+    UniquePtr<DeserializedNode> referent1(new MockDeserializedNode(1,
+                                                                   nullptr,
+                                                                   10));
+    DeserializedEdge edge1(referent1->id);
+    mocked.addEdge(Move(edge1));
+    EXPECT_CALL(mocked, getEdgeReferent(EdgeTo(referent1->id)))
+      .Times(1)
+      .WillOnce(Return(JS::ubi::Node(referent1.get())));
+
+    UniquePtr<DeserializedNode> referent2(new MockDeserializedNode(2,
+                                                                   nullptr,
+                                                                   20));
+    DeserializedEdge edge2(referent2->id);
+    mocked.addEdge(Move(edge2));
+    EXPECT_CALL(mocked, getEdgeReferent(EdgeTo(referent2->id)))
+      .Times(1)
+      .WillOnce(Return(JS::ubi::Node(referent2.get())));
+
+    UniquePtr<DeserializedNode> referent3(new MockDeserializedNode(3,
+                                                                   nullptr,
+                                                                   30));
+    DeserializedEdge edge3(referent3->id);
+    mocked.addEdge(Move(edge3));
+    EXPECT_CALL(mocked, getEdgeReferent(EdgeTo(referent3->id)))
+      .Times(1)
+      .WillOnce(Return(JS::ubi::Node(referent3.get())));
+
+    auto range = ubi.edges(cx);
+    ASSERT_TRUE(!!range);
+
+    for ( ; !range->empty(); range->popFront()) {
+      // Nothing to do here. This loop ensures that we get each edge referent
+      // that we expect above.
+    }
+  });
diff --git a/devtools/shared/heapsnapshot/tests/gtest/DeserializedStackFrameUbiStackFrames.cpp b/devtools/shared/heapsnapshot/tests/gtest/DeserializedStackFrameUbiStackFrames.cpp
new file mode 100644
index 000000000..72e363934
--- /dev/null
+++ b/devtools/shared/heapsnapshot/tests/gtest/DeserializedStackFrameUbiStackFrames.cpp
@@ -0,0 +1,91 @@
+/* -*-  Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
+/* 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/. */
+
+// Test that the `JS::ubi::StackFrame`s we create from
+// `mozilla::devtools::DeserializedStackFrame` instances look and behave as we would
+// like.
+
+#include "DevTools.h"
+#include "js/TypeDecls.h"
+#include "mozilla/devtools/DeserializedNode.h"
+
+using testing::Field;
+using testing::ReturnRef;
+
+// A mock DeserializedStackFrame for testing.
+struct MockDeserializedStackFrame : public DeserializedStackFrame
+{
+  MockDeserializedStackFrame() : DeserializedStackFrame() { }
+};
+
+DEF_TEST(DeserializedStackFrameUbiStackFrames, {
+    StackFrameId id = uint64_t(1) << 42;
+    uint32_t line = 1337;
+    uint32_t column = 9; // 3 space tabs!?
+    const char16_t* source = u"my-javascript-file.js";
+    const char16_t* functionDisplayName = u"myFunctionName";
+
+    MockDeserializedStackFrame mocked;
+    mocked.id = id;
+    mocked.line = line;
+    mocked.column = column;
+    mocked.source = source;
+    mocked.functionDisplayName = functionDisplayName;
+
+    DeserializedStackFrame& deserialized = mocked;
+    JS::ubi::StackFrame ubiFrame(&deserialized);
+
+    // Test the JS::ubi::StackFrame accessors.
+
+    EXPECT_EQ(id, ubiFrame.identifier());
+    EXPECT_EQ(JS::ubi::StackFrame(), ubiFrame.parent());
+    EXPECT_EQ(line, ubiFrame.line());
+    EXPECT_EQ(column, ubiFrame.column());
+    EXPECT_EQ(JS::ubi::AtomOrTwoByteChars(source), ubiFrame.source());
+    EXPECT_EQ(JS::ubi::AtomOrTwoByteChars(functionDisplayName),
+              ubiFrame.functionDisplayName());
+    EXPECT_FALSE(ubiFrame.isSelfHosted(cx));
+    EXPECT_FALSE(ubiFrame.isSystem());
+
+    JS::RootedObject savedFrame(cx);
+    EXPECT_TRUE(ubiFrame.constructSavedFrameStack(cx, &savedFrame));
+
+    uint32_t frameLine;
+    ASSERT_EQ(JS::SavedFrameResult::Ok, JS::GetSavedFrameLine(cx, savedFrame, &frameLine));
+    EXPECT_EQ(line, frameLine);
+
+    uint32_t frameColumn;
+    ASSERT_EQ(JS::SavedFrameResult::Ok, JS::GetSavedFrameColumn(cx, savedFrame, &frameColumn));
+    EXPECT_EQ(column, frameColumn);
+
+    JS::RootedObject parent(cx);
+    ASSERT_EQ(JS::SavedFrameResult::Ok, JS::GetSavedFrameParent(cx, savedFrame, &parent));
+    EXPECT_EQ(nullptr, parent);
+
+    ASSERT_EQ(NS_strlen(source), 21U);
+    char16_t sourceBuf[21] = {};
+
+    // Test when the length is shorter than the string length.
+    auto written = ubiFrame.source(RangedPtr<char16_t>(sourceBuf), 3);
+    EXPECT_EQ(written, 3U);
+    for (size_t i = 0; i < 3; i++) {
+      EXPECT_EQ(sourceBuf[i], source[i]);
+    }
+
+    written = ubiFrame.source(RangedPtr<char16_t>(sourceBuf), 21);
+    EXPECT_EQ(written, 21U);
+    for (size_t i = 0; i < 21; i++) {
+      EXPECT_EQ(sourceBuf[i], source[i]);
+    }
+
+    ASSERT_EQ(NS_strlen(functionDisplayName), 14U);
+    char16_t nameBuf[14] = {};
+
+    written = ubiFrame.functionDisplayName(RangedPtr<char16_t>(nameBuf), 14);
+    EXPECT_EQ(written, 14U);
+    for (size_t i = 0; i < 14; i++) {
+      EXPECT_EQ(nameBuf[i], functionDisplayName[i]);
+    }
+});
diff --git a/devtools/shared/heapsnapshot/tests/gtest/DevTools.h b/devtools/shared/heapsnapshot/tests/gtest/DevTools.h
new file mode 100644
index 000000000..6eb5cfe21
--- /dev/null
+++ b/devtools/shared/heapsnapshot/tests/gtest/DevTools.h
@@ -0,0 +1,276 @@
+/* -*-  Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
+/* 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_devtools_gtest_DevTools__
+#define mozilla_devtools_gtest_DevTools__
+
+#include "CoreDump.pb.h"
+#include "jsapi.h"
+#include "jspubtd.h"
+#include "nsCRTGlue.h"
+
+#include "gtest/gtest.h"
+#include "gmock/gmock.h"
+#include "mozilla/devtools/HeapSnapshot.h"
+#include "mozilla/dom/ChromeUtils.h"
+#include "mozilla/CycleCollectedJSContext.h"
+#include "mozilla/Move.h"
+#include "js/Principals.h"
+#include "js/UbiNode.h"
+#include "js/UniquePtr.h"
+
+using namespace mozilla;
+using namespace mozilla::devtools;
+using namespace mozilla::dom;
+using namespace testing;
+
+// GTest fixture class that all of our tests derive from.
+struct DevTools : public ::testing::Test {
+  bool                       _initialized;
+  JSContext*                 cx;
+  JSCompartment*             compartment;
+  JS::Zone*                  zone;
+  JS::PersistentRootedObject global;
+
+  DevTools()
+    : _initialized(false),
+      cx(nullptr)
+  { }
+
+  virtual void SetUp() {
+    MOZ_ASSERT(!_initialized);
+
+    cx = getContext();
+    if (!cx)
+      return;
+
+    JS_BeginRequest(cx);
+
+    global.init(cx, createGlobal());
+    if (!global)
+      return;
+    JS_EnterCompartment(cx, global);
+
+    compartment = js::GetContextCompartment(cx);
+    zone = js::GetContextZone(cx);
+
+    _initialized = true;
+  }
+
+  JSContext* getContext() {
+    return CycleCollectedJSContext::Get()->Context();
+  }
+
+  static void reportError(JSContext* cx, const char* message, JSErrorReport* report) {
+    fprintf(stderr, "%s:%u:%s\n",
+            report->filename ? report->filename : "<no filename>",
+            (unsigned int) report->lineno,
+            message);
+  }
+
+  static const JSClass* getGlobalClass() {
+    static const JSClassOps globalClassOps = {
+      nullptr, nullptr, nullptr, nullptr,
+      nullptr, nullptr, nullptr, nullptr,
+      nullptr, nullptr, nullptr,
+      JS_GlobalObjectTraceHook
+    };
+    static const JSClass globalClass = {
+      "global", JSCLASS_GLOBAL_FLAGS,
+      &globalClassOps
+    };
+    return &globalClass;
+  }
+
+  JSObject* createGlobal()
+  {
+    /* Create the global object. */
+    JS::RootedObject newGlobal(cx);
+    JS::CompartmentOptions options;
+    options.behaviors().setVersion(JSVERSION_LATEST);
+    newGlobal = JS_NewGlobalObject(cx, getGlobalClass(), nullptr,
+                                   JS::FireOnNewGlobalHook, options);
+    if (!newGlobal)
+      return nullptr;
+
+    JSAutoCompartment ac(cx, newGlobal);
+
+    /* Populate the global object with the standard globals, like Object and
+       Array. */
+    if (!JS_InitStandardClasses(cx, newGlobal))
+      return nullptr;
+
+    return newGlobal;
+  }
+
+  virtual void TearDown() {
+    _initialized = false;
+
+    if (global) {
+      JS_LeaveCompartment(cx, nullptr);
+      global = nullptr;
+    }
+    if (cx)
+      JS_EndRequest(cx);
+  }
+};
+
+
+// Helper to define a test and ensure that the fixture is initialized properly.
+#define DEF_TEST(name, body)                    \
+  TEST_F(DevTools, name) {                      \
+    ASSERT_TRUE(_initialized);                  \
+    body                                        \
+  }
+
+
+// Fake JS::ubi::Node implementation
+class MOZ_STACK_CLASS FakeNode
+{
+public:
+  JS::ubi::EdgeVector edges;
+  JSCompartment*      compartment;
+  JS::Zone*           zone;
+  size_t              size;
+
+  explicit FakeNode()
+    : edges(),
+    compartment(nullptr),
+    zone(nullptr),
+    size(1)
+  { }
+};
+
+namespace JS {
+namespace ubi {
+
+template<>
+class Concrete<FakeNode> : public Base
+{
+  const char16_t* typeName() const override {
+    return concreteTypeName;
+  }
+
+  js::UniquePtr<EdgeRange> edges(JSContext*, bool) const override {
+    return js::UniquePtr<EdgeRange>(js_new<PreComputedEdgeRange>(get().edges));
+  }
+
+  Size size(mozilla::MallocSizeOf) const override {
+    return get().size;
+  }
+
+  JS::Zone* zone() const override {
+    return get().zone;
+  }
+
+  JSCompartment* compartment() const override {
+    return get().compartment;
+  }
+
+protected:
+  explicit Concrete(FakeNode* ptr) : Base(ptr) { }
+  FakeNode& get() const { return *static_cast<FakeNode*>(ptr); }
+
+public:
+  static const char16_t concreteTypeName[];
+  static void construct(void* storage, FakeNode* ptr) {
+    new (storage) Concrete(ptr);
+  }
+};
+
+const char16_t Concrete<FakeNode>::concreteTypeName[] = u"FakeNode";
+
+} // namespace ubi
+} // namespace JS
+
+void AddEdge(FakeNode& node, FakeNode& referent, const char16_t* edgeName = nullptr) {
+  char16_t* ownedEdgeName = nullptr;
+  if (edgeName) {
+    ownedEdgeName = NS_strdup(edgeName);
+    ASSERT_NE(ownedEdgeName, nullptr);
+  }
+
+  JS::ubi::Edge edge(ownedEdgeName, &referent);
+  ASSERT_TRUE(node.edges.append(mozilla::Move(edge)));
+}
+
+
+// Custom GMock Matchers
+
+// Use the testing namespace to avoid static analysis failures in the gmock
+// matcher classes that get generated from MATCHER_P macros.
+namespace testing {
+
+// Ensure that given node has the expected number of edges.
+MATCHER_P2(EdgesLength, cx, expectedLength, "") {
+  auto edges = arg.edges(cx);
+  if (!edges)
+    return false;
+
+  int actualLength = 0;
+  for ( ; !edges->empty(); edges->popFront())
+    actualLength++;
+
+  return Matcher<int>(Eq(expectedLength))
+    .MatchAndExplain(actualLength, result_listener);
+}
+
+// Get the nth edge and match it with the given matcher.
+MATCHER_P3(Edge, cx, n, matcher, "") {
+  auto edges = arg.edges(cx);
+  if (!edges)
+    return false;
+
+  int i = 0;
+  for ( ; !edges->empty(); edges->popFront()) {
+    if (i == n) {
+      return Matcher<const JS::ubi::Edge&>(matcher)
+        .MatchAndExplain(edges->front(), result_listener);
+    }
+
+    i++;
+  }
+
+  return false;
+}
+
+// Ensures that two char16_t* strings are equal.
+MATCHER_P(UTF16StrEq, str, "") {
+  return NS_strcmp(arg, str) == 0;
+}
+
+MATCHER_P(UniqueUTF16StrEq, str, "") {
+  return NS_strcmp(arg.get(), str) == 0;
+}
+
+MATCHER(UniqueIsNull, "") {
+  return arg.get() == nullptr;
+}
+
+// Matches an edge whose referent is the node with the given id.
+MATCHER_P(EdgeTo, id, "") {
+  return Matcher<const DeserializedEdge&>(Field(&DeserializedEdge::referent, id))
+    .MatchAndExplain(arg, result_listener);
+}
+
+} // namespace testing
+
+
+// A mock `Writer` class to be used with testing `WriteHeapGraph`.
+class MockWriter : public CoreDumpWriter
+{
+public:
+  virtual ~MockWriter() override { }
+  MOCK_METHOD2(writeNode, bool(const JS::ubi::Node&, CoreDumpWriter::EdgePolicy));
+  MOCK_METHOD1(writeMetadata, bool(uint64_t));
+};
+
+void ExpectWriteNode(MockWriter& writer, FakeNode& node) {
+  EXPECT_CALL(writer, writeNode(Eq(JS::ubi::Node(&node)), _))
+    .Times(1)
+    .WillOnce(Return(true));
+}
+
+#endif // mozilla_devtools_gtest_DevTools__
diff --git a/devtools/shared/heapsnapshot/tests/gtest/DoesCrossCompartmentBoundaries.cpp b/devtools/shared/heapsnapshot/tests/gtest/DoesCrossCompartmentBoundaries.cpp
new file mode 100644
index 000000000..bc517d6d9
--- /dev/null
+++ b/devtools/shared/heapsnapshot/tests/gtest/DoesCrossCompartmentBoundaries.cpp
@@ -0,0 +1,73 @@
+/* -*-  Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
+/* 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/. */
+
+// Test that heap snapshots cross compartment boundaries when expected.
+
+#include "DevTools.h"
+
+DEF_TEST(DoesCrossCompartmentBoundaries, {
+    // Create a new global to get a new compartment.
+    JS::CompartmentOptions options;
+    JS::RootedObject newGlobal(cx, JS_NewGlobalObject(cx,
+                                                      getGlobalClass(),
+                                                      nullptr,
+                                                      JS::FireOnNewGlobalHook,
+                                                      options));
+    ASSERT_TRUE(newGlobal);
+    JSCompartment* newCompartment = nullptr;
+    {
+      JSAutoCompartment ac(cx, newGlobal);
+      ASSERT_TRUE(JS_InitStandardClasses(cx, newGlobal));
+      newCompartment = js::GetContextCompartment(cx);
+    }
+    ASSERT_TRUE(newCompartment);
+    ASSERT_NE(newCompartment, compartment);
+
+    // Our set of target compartments is both the old and new compartments.
+    JS::CompartmentSet targetCompartments;
+    ASSERT_TRUE(targetCompartments.init());
+    ASSERT_TRUE(targetCompartments.put(compartment));
+    ASSERT_TRUE(targetCompartments.put(newCompartment));
+
+    FakeNode nodeA;
+    FakeNode nodeB;
+    FakeNode nodeC;
+    FakeNode nodeD;
+
+    nodeA.compartment = compartment;
+    nodeB.compartment = nullptr;
+    nodeC.compartment = newCompartment;
+    nodeD.compartment = nullptr;
+
+    AddEdge(nodeA, nodeB);
+    AddEdge(nodeA, nodeC);
+    AddEdge(nodeB, nodeD);
+
+    ::testing::NiceMock<MockWriter> writer;
+
+    // Should serialize nodeA, because it is in one of our target compartments.
+    ExpectWriteNode(writer, nodeA);
+
+    // Should serialize nodeB, because it doesn't belong to a compartment and is
+    // therefore assumed to be shared.
+    ExpectWriteNode(writer, nodeB);
+
+    // Should also serialize nodeC, which is in our target compartments, but a
+    // different compartment than A.
+    ExpectWriteNode(writer, nodeC);
+
+    // Should serialize nodeD because it's reachable via B and both nodes B and D
+    // don't belong to a specific compartment.
+    ExpectWriteNode(writer, nodeD);
+
+    JS::AutoCheckCannotGC noGC(cx);
+
+    ASSERT_TRUE(WriteHeapGraph(cx,
+                               JS::ubi::Node(&nodeA),
+                               writer,
+                               /* wantNames = */ false,
+                               &targetCompartments,
+                               noGC));
+  });
diff --git a/devtools/shared/heapsnapshot/tests/gtest/DoesntCrossCompartmentBoundaries.cpp b/devtools/shared/heapsnapshot/tests/gtest/DoesntCrossCompartmentBoundaries.cpp
new file mode 100644
index 000000000..2fe5e6ace
--- /dev/null
+++ b/devtools/shared/heapsnapshot/tests/gtest/DoesntCrossCompartmentBoundaries.cpp
@@ -0,0 +1,64 @@
+/* -*-  Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
+/* 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/. */
+
+// Test that heap snapshots walk the compartment boundaries correctly.
+
+#include "DevTools.h"
+
+DEF_TEST(DoesntCrossCompartmentBoundaries, {
+    // Create a new global to get a new compartment.
+    JS::CompartmentOptions options;
+    JS::RootedObject newGlobal(cx, JS_NewGlobalObject(cx,
+                                                      getGlobalClass(),
+                                                      nullptr,
+                                                      JS::FireOnNewGlobalHook,
+                                                      options));
+    ASSERT_TRUE(newGlobal);
+    JSCompartment* newCompartment = nullptr;
+    {
+      JSAutoCompartment ac(cx, newGlobal);
+      ASSERT_TRUE(JS_InitStandardClasses(cx, newGlobal));
+      newCompartment = js::GetContextCompartment(cx);
+    }
+    ASSERT_TRUE(newCompartment);
+    ASSERT_NE(newCompartment, compartment);
+
+    // Our set of target compartments is only the pre-existing compartment and
+    // does not include the new compartment.
+    JS::CompartmentSet targetCompartments;
+    ASSERT_TRUE(targetCompartments.init());
+    ASSERT_TRUE(targetCompartments.put(compartment));
+
+    FakeNode nodeA;
+    FakeNode nodeB;
+    FakeNode nodeC;
+
+    nodeA.compartment = compartment;
+    nodeB.compartment = nullptr;
+    nodeC.compartment = newCompartment;
+
+    AddEdge(nodeA, nodeB);
+    AddEdge(nodeB, nodeC);
+
+    ::testing::NiceMock<MockWriter> writer;
+
+    // Should serialize nodeA, because it is in our target compartments.
+    ExpectWriteNode(writer, nodeA);
+
+    // Should serialize nodeB, because it doesn't belong to a compartment and is
+    // therefore assumed to be shared.
+    ExpectWriteNode(writer, nodeB);
+
+    // But we shouldn't ever serialize nodeC.
+
+    JS::AutoCheckCannotGC noGC(cx);
+
+    ASSERT_TRUE(WriteHeapGraph(cx,
+                               JS::ubi::Node(&nodeA),
+                               writer,
+                               /* wantNames = */ false,
+                               &targetCompartments,
+                               noGC));
+  });
diff --git a/devtools/shared/heapsnapshot/tests/gtest/SerializesEdgeNames.cpp b/devtools/shared/heapsnapshot/tests/gtest/SerializesEdgeNames.cpp
new file mode 100644
index 000000000..be135dbb4
--- /dev/null
+++ b/devtools/shared/heapsnapshot/tests/gtest/SerializesEdgeNames.cpp
@@ -0,0 +1,53 @@
+/* -*-  Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
+/* 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/. */
+
+// Test that edge names get serialized correctly.
+
+#include "DevTools.h"
+
+using testing::Field;
+using testing::IsNull;
+using testing::Property;
+using testing::Return;
+
+DEF_TEST(SerializesEdgeNames, {
+    FakeNode node;
+    FakeNode referent;
+
+    const char16_t edgeName[] = u"edge name";
+    const char16_t emptyStr[] = u"";
+
+    AddEdge(node, referent, edgeName);
+    AddEdge(node, referent, emptyStr);
+    AddEdge(node, referent, nullptr);
+
+    ::testing::NiceMock<MockWriter> writer;
+
+    // Should get the node with edges once.
+    EXPECT_CALL(
+      writer,
+      writeNode(AllOf(EdgesLength(cx, 3),
+                      Edge(cx, 0, Field(&JS::ubi::Edge::name,
+                                        UniqueUTF16StrEq(edgeName))),
+                      Edge(cx, 1, Field(&JS::ubi::Edge::name,
+                                        UniqueUTF16StrEq(emptyStr))),
+                      Edge(cx, 2, Field(&JS::ubi::Edge::name,
+                                        UniqueIsNull()))),
+                _)
+    )
+      .Times(1)
+      .WillOnce(Return(true));
+
+    // Should get the referent node that doesn't have any edges once.
+    ExpectWriteNode(writer, referent);
+
+    JS::AutoCheckCannotGC noGC(cx);
+    ASSERT_TRUE(WriteHeapGraph(cx,
+                               JS::ubi::Node(&node),
+                               writer,
+                               /* wantNames = */ true,
+                               /* zones = */ nullptr,
+                               noGC));
+  });
diff --git a/devtools/shared/heapsnapshot/tests/gtest/SerializesEverythingInHeapGraphOnce.cpp b/devtools/shared/heapsnapshot/tests/gtest/SerializesEverythingInHeapGraphOnce.cpp
new file mode 100644
index 000000000..475442df8
--- /dev/null
+++ b/devtools/shared/heapsnapshot/tests/gtest/SerializesEverythingInHeapGraphOnce.cpp
@@ -0,0 +1,37 @@
+/* -*-  Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
+/* 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/. */
+
+// Test that everything in the heap graph gets serialized once, and only once.
+
+#include "DevTools.h"
+
+DEF_TEST(SerializesEverythingInHeapGraphOnce, {
+    FakeNode nodeA;
+    FakeNode nodeB;
+    FakeNode nodeC;
+    FakeNode nodeD;
+
+    AddEdge(nodeA, nodeB);
+    AddEdge(nodeB, nodeC);
+    AddEdge(nodeC, nodeD);
+    AddEdge(nodeD, nodeA);
+
+    ::testing::NiceMock<MockWriter> writer;
+
+    // Should serialize each node once.
+    ExpectWriteNode(writer, nodeA);
+    ExpectWriteNode(writer, nodeB);
+    ExpectWriteNode(writer, nodeC);
+    ExpectWriteNode(writer, nodeD);
+
+    JS::AutoCheckCannotGC noGC(cx);
+
+    ASSERT_TRUE(WriteHeapGraph(cx,
+                               JS::ubi::Node(&nodeA),
+                               writer,
+                               /* wantNames = */ false,
+                               /* zones = */ nullptr,
+                               noGC));
+  });
diff --git a/devtools/shared/heapsnapshot/tests/gtest/SerializesTypeNames.cpp b/devtools/shared/heapsnapshot/tests/gtest/SerializesTypeNames.cpp
new file mode 100644
index 000000000..a259c297b
--- /dev/null
+++ b/devtools/shared/heapsnapshot/tests/gtest/SerializesTypeNames.cpp
@@ -0,0 +1,30 @@
+/* -*-  Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
+/* 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/. */
+
+// Test that a ubi::Node's typeName gets properly serialized into a core dump.
+
+#include "DevTools.h"
+
+using testing::Property;
+using testing::Return;
+
+DEF_TEST(SerializesTypeNames, {
+    FakeNode node;
+
+    ::testing::NiceMock<MockWriter> writer;
+    EXPECT_CALL(writer, writeNode(Property(&JS::ubi::Node::typeName,
+                                           UTF16StrEq(u"FakeNode")),
+                                  _))
+      .Times(1)
+      .WillOnce(Return(true));
+
+    JS::AutoCheckCannotGC noGC(cx);
+    ASSERT_TRUE(WriteHeapGraph(cx,
+                               JS::ubi::Node(&node),
+                               writer,
+                               /* wantNames = */ true,
+                               /* zones = */ nullptr,
+                               noGC));
+  });
diff --git a/devtools/shared/heapsnapshot/tests/gtest/moz.build b/devtools/shared/heapsnapshot/tests/gtest/moz.build
new file mode 100644
index 000000000..08c31e47c
--- /dev/null
+++ b/devtools/shared/heapsnapshot/tests/gtest/moz.build
@@ -0,0 +1,31 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+Library('devtoolstests')
+
+LOCAL_INCLUDES += [
+    '../..',
+]
+
+UNIFIED_SOURCES = [
+    'DeserializedNodeUbiNodes.cpp',
+    'DeserializedStackFrameUbiStackFrames.cpp',
+    'DoesCrossCompartmentBoundaries.cpp',
+    'DoesntCrossCompartmentBoundaries.cpp',
+    'SerializesEdgeNames.cpp',
+    'SerializesEverythingInHeapGraphOnce.cpp',
+    'SerializesTypeNames.cpp',
+]
+
+if CONFIG['GNU_CXX']:
+    CXXFLAGS += ['-Wno-error=shadow']
+
+# THE MOCK_METHOD2 macro from gtest triggers this clang warning and it's hard
+# to work around, so we just ignore it.
+if CONFIG['CLANG_CXX']:
+  CXXFLAGS += ['-Wno-inconsistent-missing-override']
+
+FINAL_LIBRARY = 'xul-gtest'