1 files changed, 281 insertions, 0 deletions
diff --git a/xpcom/tests/gtest/TestObserverService.cpp b/xpcom/tests/gtest/TestObserverService.cpp
new file mode 100644
index 0000000000..4126815f1f
--- /dev/null
+++ b/xpcom/tests/gtest/TestObserverService.cpp
@@ -0,0 +1,281 @@
+/* -*- 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/. */
+
+#include "nsISupports.h"
+#include "nsIObserverService.h"
+#include "nsIObserver.h"
+#include "nsISimpleEnumerator.h"
+#include "nsComponentManagerUtils.h"
+
+#include "nsCOMPtr.h"
+#include "nsString.h"
+#include "nsWeakReference.h"
+
+#include "mozilla/gtest/MozAssertions.h"
+#include "mozilla/RefPtr.h"
+
+#include "gtest/gtest.h"
+
+static void testResult(nsresult rv) {
+  EXPECT_TRUE(NS_SUCCEEDED(rv)) << "0x" << std::hex << (int)rv;
+}
+
+class TestObserver final : public nsIObserver, public nsSupportsWeakReference {
+ public:
+  explicit TestObserver(const nsAString& name)
+      : mName(name), mObservations(0) {}
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIOBSERVER
+
+  nsString mName;
+  int mObservations;
+  static int sTotalObservations;
+
+  nsString mExpectedData;
+
+ private:
+  ~TestObserver() = default;
+};
+
+NS_IMPL_ISUPPORTS(TestObserver, nsIObserver, nsISupportsWeakReference)
+
+int TestObserver::sTotalObservations;
+
+NS_IMETHODIMP
+TestObserver::Observe(nsISupports* aSubject, const char* aTopic,
+                      const char16_t* someData) {
+  mObservations++;
+  sTotalObservations++;
+
+  if (!mExpectedData.IsEmpty()) {
+    EXPECT_TRUE(mExpectedData.Equals(someData));
+  }
+
+  return NS_OK;
+}
+
+static nsISupports* ToSupports(TestObserver* aObs) {
+  return static_cast<nsIObserver*>(aObs);
+}
+
+static void TestExpectedCount(nsIObserverService* svc, const char* topic,
+                              size_t expected) {
+  nsCOMPtr<nsISimpleEnumerator> e;
+  nsresult rv = svc->EnumerateObservers(topic, getter_AddRefs(e));
+  testResult(rv);
+  EXPECT_TRUE(e);
+
+  bool hasMore = false;
+  rv = e->HasMoreElements(&hasMore);
+  testResult(rv);
+
+  if (expected == 0) {
+    EXPECT_FALSE(hasMore);
+    return;
+  }
+
+  size_t count = 0;
+  while (hasMore) {
+    count++;
+
+    // Grab the element.
+    nsCOMPtr<nsISupports> supports;
+    e->GetNext(getter_AddRefs(supports));
+    ASSERT_TRUE(supports);
+
+    // Move on.
+    rv = e->HasMoreElements(&hasMore);
+    testResult(rv);
+  }
+
+  EXPECT_EQ(count, expected);
+}
+
+TEST(ObserverService, Creation)
+{
+  nsresult rv;
+  nsCOMPtr<nsIObserverService> svc =
+      do_CreateInstance("@mozilla.org/observer-service;1", &rv);
+
+  ASSERT_EQ(rv, NS_OK);
+  ASSERT_TRUE(svc);
+}
+
+TEST(ObserverService, AddObserver)
+{
+  nsCOMPtr<nsIObserverService> svc =
+      do_CreateInstance("@mozilla.org/observer-service;1");
+
+  // Add a strong ref.
+  RefPtr<TestObserver> a = new TestObserver(u"A"_ns);
+  nsresult rv = svc->AddObserver(a, "Foo", false);
+  testResult(rv);
+
+  // Add a few weak ref.
+  RefPtr<TestObserver> b = new TestObserver(u"B"_ns);
+  rv = svc->AddObserver(b, "Bar", true);
+  testResult(rv);
+}
+
+TEST(ObserverService, RemoveObserver)
+{
+  nsCOMPtr<nsIObserverService> svc =
+      do_CreateInstance("@mozilla.org/observer-service;1");
+
+  RefPtr<TestObserver> a = new TestObserver(u"A"_ns);
+  RefPtr<TestObserver> b = new TestObserver(u"B"_ns);
+  RefPtr<TestObserver> c = new TestObserver(u"C"_ns);
+
+  svc->AddObserver(a, "Foo", false);
+  svc->AddObserver(b, "Foo", true);
+
+  // Remove from non-existent topic.
+  nsresult rv = svc->RemoveObserver(a, "Bar");
+  ASSERT_NS_FAILED(rv);
+
+  // Remove a.
+  testResult(svc->RemoveObserver(a, "Foo"));
+
+  // Remove b.
+  testResult(svc->RemoveObserver(b, "Foo"));
+
+  // Attempt to remove c.
+  rv = svc->RemoveObserver(c, "Foo");
+  ASSERT_NS_FAILED(rv);
+}
+
+TEST(ObserverService, EnumerateEmpty)
+{
+  nsCOMPtr<nsIObserverService> svc =
+      do_CreateInstance("@mozilla.org/observer-service;1");
+
+  // Try with no observers.
+  TestExpectedCount(svc, "A", 0);
+
+  // Now add an observer and enumerate an unobserved topic.
+  RefPtr<TestObserver> a = new TestObserver(u"A"_ns);
+  testResult(svc->AddObserver(a, "Foo", false));
+
+  TestExpectedCount(svc, "A", 0);
+}
+
+TEST(ObserverService, Enumerate)
+{
+  nsCOMPtr<nsIObserverService> svc =
+      do_CreateInstance("@mozilla.org/observer-service;1");
+
+  const size_t kFooCount = 10;
+  for (size_t i = 0; i < kFooCount; i++) {
+    RefPtr<TestObserver> a = new TestObserver(u"A"_ns);
+    testResult(svc->AddObserver(a, "Foo", false));
+  }
+
+  const size_t kBarCount = kFooCount / 2;
+  for (size_t i = 0; i < kBarCount; i++) {
+    RefPtr<TestObserver> a = new TestObserver(u"A"_ns);
+    testResult(svc->AddObserver(a, "Bar", false));
+  }
+
+  // Enumerate "Foo".
+  TestExpectedCount(svc, "Foo", kFooCount);
+
+  // Enumerate "Bar".
+  TestExpectedCount(svc, "Bar", kBarCount);
+}
+
+TEST(ObserverService, EnumerateWeakRefs)
+{
+  nsCOMPtr<nsIObserverService> svc =
+      do_CreateInstance("@mozilla.org/observer-service;1");
+
+  const size_t kFooCount = 10;
+  for (size_t i = 0; i < kFooCount; i++) {
+    RefPtr<TestObserver> a = new TestObserver(u"A"_ns);
+    testResult(svc->AddObserver(a, "Foo", true));
+  }
+
+  // All refs are out of scope, expect enumeration to be empty.
+  TestExpectedCount(svc, "Foo", 0);
+
+  // Now test a mixture.
+  for (size_t i = 0; i < kFooCount; i++) {
+    RefPtr<TestObserver> a = new TestObserver(u"A"_ns);
+    RefPtr<TestObserver> b = new TestObserver(u"B"_ns);
+
+    // Register a as weak for "Foo".
+    testResult(svc->AddObserver(a, "Foo", true));
+
+    // Register b as strong for "Foo".
+    testResult(svc->AddObserver(b, "Foo", false));
+  }
+
+  // Expect the b instances to stick around.
+  TestExpectedCount(svc, "Foo", kFooCount);
+
+  // Now add a couple weak refs, but don't go out of scope.
+  RefPtr<TestObserver> a = new TestObserver(u"A"_ns);
+  testResult(svc->AddObserver(a, "Foo", true));
+  RefPtr<TestObserver> b = new TestObserver(u"B"_ns);
+  testResult(svc->AddObserver(b, "Foo", true));
+
+  // Expect all the observers from before and the two new ones.
+  TestExpectedCount(svc, "Foo", kFooCount + 2);
+}
+
+TEST(ObserverService, TestNotify)
+{
+  nsCString topicA;
+  topicA.Assign("topic-A");
+  nsCString topicB;
+  topicB.Assign("topic-B");
+
+  nsCOMPtr<nsIObserverService> svc =
+      do_CreateInstance("@mozilla.org/observer-service;1");
+
+  RefPtr<TestObserver> aObserver = new TestObserver(u"Observer-A"_ns);
+  RefPtr<TestObserver> bObserver = new TestObserver(u"Observer-B"_ns);
+
+  // Add two observers for topicA.
+  testResult(svc->AddObserver(aObserver, topicA.get(), false));
+  testResult(svc->AddObserver(bObserver, topicA.get(), false));
+
+  // Add one observer for topicB.
+  testResult(svc->AddObserver(bObserver, topicB.get(), false));
+
+  // Notify topicA.
+  const char16_t* dataA = u"Testing Notify(observer-A, topic-A)";
+  aObserver->mExpectedData = dataA;
+  bObserver->mExpectedData = dataA;
+  nsresult rv =
+      svc->NotifyObservers(ToSupports(aObserver), topicA.get(), dataA);
+  testResult(rv);
+  ASSERT_EQ(aObserver->mObservations, 1);
+  ASSERT_EQ(bObserver->mObservations, 1);
+
+  // Notify topicB.
+  const char16_t* dataB = u"Testing Notify(observer-B, topic-B)";
+  bObserver->mExpectedData = dataB;
+  rv = svc->NotifyObservers(ToSupports(bObserver), topicB.get(), dataB);
+  testResult(rv);
+  ASSERT_EQ(aObserver->mObservations, 1);
+  ASSERT_EQ(bObserver->mObservations, 2);
+
+  // Remove one of the topicA observers, make sure it's not notified.
+  testResult(svc->RemoveObserver(aObserver, topicA.get()));
+
+  // Notify topicA, only bObserver is expected to be notified.
+  bObserver->mExpectedData = dataA;
+  rv = svc->NotifyObservers(ToSupports(aObserver), topicA.get(), dataA);
+  testResult(rv);
+  ASSERT_EQ(aObserver->mObservations, 1);
+  ASSERT_EQ(bObserver->mObservations, 3);
+
+  // Remove the other topicA observer, make sure none are notified.
+  testResult(svc->RemoveObserver(bObserver, topicA.get()));
+  rv = svc->NotifyObservers(ToSupports(aObserver), topicA.get(), dataA);
+  testResult(rv);
+  ASSERT_EQ(aObserver->mObservations, 1);
+  ASSERT_EQ(bObserver->mObservations, 3);
+}