text: // Copyright 2005, Google Inc.
  // All rights reserved.
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //     * Neither the name of Google Inc. nor the names of its
  // contributors may be used to endorse or promote products derived from
  // this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  // A sample program demonstrating using Google C++ testing framework.
  //
  // Author: wan@google.com (Zhanyong Wan)
  
  
  // In this example, we use a more advanced feature of Google Test called
  // test fixture.
  //
  // A test fixture is a place to hold objects and functions shared by
  // all tests in a test case.  Using a test fixture avoids duplicating
  // the test code necessary to initialize and cleanup those common
  // objects for each test.  It is also useful for defining sub-routines
  // that your tests need to invoke a lot.
  //
  // <TechnicalDetails>
  //
  // The tests share the test fixture in the sense of code sharing, not
  // data sharing.  Each test is given its own fresh copy of the
  // fixture.  You cannot expect the data modified by one test to be
  // passed on to another test, which is a bad idea.
  //
  // The reason for this design is that tests should be independent and
  // repeatable.  In particular, a test should not fail as the result of
  // another test's failure.  If one test depends on info produced by
  // another test, then the two tests should really be one big test.
  //
  // The macros for indicating the success/failure of a test
  // (EXPECT_TRUE, FAIL, etc) need to know what the current test is
  // (when Google Test prints the test result, it tells you which test
  // each failure belongs to).  Technically, these macros invoke a
  // member function of the Test class.  Therefore, you cannot use them
  // in a global function.  That's why you should put test sub-routines
  // in a test fixture.
  //
  // </TechnicalDetails>
  
  #include "../src/sample3-inl.h"
  #include "gtest/gtest.h"
  
  // To use a test fixture, derive a class from testing::Test.
  class QueueTest : public testing::Test {
   protected:  // You should make the members protected s.t. they can be
               // accessed from sub-classes.
  
    // virtual void SetUp() will be called before each test is run.  You
    // should define it if you need to initialize the varaibles.
    // Otherwise, this can be skipped.
    virtual void SetUp() {
      q1_.Enqueue(1);
      q2_.Enqueue(2);
      q2_.Enqueue(3);
    }
  
    // virtual void TearDown() will be called after each test is run.
    // You should define it if there is cleanup work to do.  Otherwise,
    // you don't have to provide it.
    //
    // virtual void TearDown() {
    // }
  
    // A helper function that some test uses.
    static int Double(int n) {
      return 2*n;
    }
  
    // A helper function for testing Queue::Map().
    void MapTester(const Queue<int> * q) {
      // Creates a new queue, where each element is twice as big as the
      // corresponding one in q.
      const Queue<int> * const new_q = q->Map(Double);
  
      // Verifies that the new queue has the same size as q.
      ASSERT_EQ(q->Size(), new_q->Size());
  
      // Verifies the relationship between the elements of the two queues.
      for ( const QueueNode<int> * n1 = q->Head(), * n2 = new_q->Head();
            n1 != NULL; n1 = n1->next(), n2 = n2->next() ) {
        EXPECT_EQ(2 * n1->element(), n2->element());
      }
  
      delete new_q;
    }
  
    // Declares the variables your tests want to use.
    Queue<int> q0_;
    Queue<int> q1_;
    Queue<int> q2_;
  };
  
  // When you have a test fixture, you define a test using TEST_F
  // instead of TEST.
  
  // Tests the default c'tor.
  TEST_F(QueueTest, DefaultConstructor) {
    // You can access data in the test fixture here.
    EXPECT_EQ(0u, q0_.Size());
  }
  
  // Tests Dequeue().
  TEST_F(QueueTest, Dequeue) {
    int * n = q0_.Dequeue();
    EXPECT_TRUE(n == NULL);
  
    n = q1_.Dequeue();
    ASSERT_TRUE(n != NULL);
    EXPECT_EQ(1, *n);
    EXPECT_EQ(0u, q1_.Size());
    delete n;
  
    n = q2_.Dequeue();
    ASSERT_TRUE(n != NULL);
    EXPECT_EQ(2, *n);
    EXPECT_EQ(1u, q2_.Size());
    delete n;
  }
  
  // Tests the Queue::Map() function.
  TEST_F(QueueTest, Map) {
    MapTester(&q0_);
    MapTester(&q1_);
    MapTester(&q2_);
  }
  