1 files changed, 76 insertions, 0 deletions
diff --git a/xpcom/tests/gtest/TestPriorityQueue.cpp b/xpcom/tests/gtest/TestPriorityQueue.cpp
new file mode 100644
index 000000000..eeb2f1e09
--- /dev/null
+++ b/xpcom/tests/gtest/TestPriorityQueue.cpp
@@ -0,0 +1,76 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 "nsTPriorityQueue.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include "gtest/gtest.h"
+
+template<class T, class Compare>
+void
+CheckPopSequence(const nsTPriorityQueue<T, Compare>& aQueue,
+                 const T* aExpectedSequence, const uint32_t aSequenceLength)
+{
+  nsTPriorityQueue<T, Compare> copy(aQueue);
+
+  for (uint32_t i = 0; i < aSequenceLength; i++) {
+    EXPECT_FALSE(copy.IsEmpty());
+
+    T pop = copy.Pop();
+    EXPECT_EQ(pop, aExpectedSequence[i]);
+  }
+
+  EXPECT_TRUE(copy.IsEmpty());
+}
+
+template<class A>
+class MaxCompare {
+public:
+  bool LessThan(const A& a, const A& b) {
+    return a > b;
+  }
+};
+
+TEST(PriorityQueue, Main)
+{
+  nsTPriorityQueue<int> queue;
+
+  EXPECT_TRUE(queue.IsEmpty());
+
+  queue.Push(8);
+  queue.Push(6);
+  queue.Push(4);
+  queue.Push(2);
+  queue.Push(10);
+  queue.Push(6);
+  EXPECT_EQ(queue.Top(), 2);
+  EXPECT_EQ(queue.Length(), 6u);
+  EXPECT_FALSE(queue.IsEmpty());
+  int expected[] = { 2, 4, 6, 6, 8, 10 };
+  CheckPopSequence(queue, expected, sizeof(expected) / sizeof(expected[0]));
+
+  // copy ctor is tested by using CheckPopSequence, but check default assignment
+  // operator
+  nsTPriorityQueue<int> queue2;
+  queue2 = queue;
+  CheckPopSequence(queue2, expected, sizeof(expected) / sizeof(expected[0]));
+
+  queue.Clear();
+  EXPECT_TRUE(queue.IsEmpty());
+
+  // try same sequence with a max heap
+  nsTPriorityQueue<int, MaxCompare<int> > max_queue;
+  max_queue.Push(8);
+  max_queue.Push(6);
+  max_queue.Push(4);
+  max_queue.Push(2);
+  max_queue.Push(10);
+  max_queue.Push(6);
+  EXPECT_EQ(max_queue.Top(), 10);
+  int expected_max[] = { 10, 8, 6, 6, 4, 2 };
+  CheckPopSequence(max_queue, expected_max,
+      sizeof(expected_max) / sizeof(expected_max[0]));
+}