Google单元测试sample分析（二）

本文开始介绍googletest/googletest/sample/sample5_unittest.cc
有关TEST_F测试夹具的使用案例

class QuickTest : public testing::Test {
 protected:
  // Remember that SetUp() is run immediately before a test starts.
  // This is a good place to record the start time.
  void SetUp() override { start_time_ = time(nullptr); }

  // TearDown() is invoked immediately after a test finishes.  Here we
  // check if the test was too slow.
  void TearDown() override {
    // Gets the time when the test finishes
    const time_t end_time = time(nullptr);

    // Asserts that the test took no more than ~5 seconds.  Did you
    // know that you can use assertions in SetUp() and TearDown() as
    // well?
    EXPECT_TRUE(end_time - start_time_ <= 5) << "The test took too long.";
  }

  // The UTC time (in seconds) when the test starts
  time_t start_time_;
};

这里的QuickTest继承自testing::Test，并重写SetUp和TearDown方法，SetUp方法在每个TEST_F开始运行一次，退出执行TearDown方法一次。
这个案例里记录整个TEST_F测试夹具的测试用例的运行时间

class IntegerFunctionTest : public QuickTest {
  // We don't need any more logic than already in the QuickTest fixture.
  // Therefore the body is empty.
};


// Now we can write tests in the IntegerFunctionTest test case.

// Tests Factorial()
TEST_F(IntegerFunctionTest, Factorial) {
  // Tests factorial of negative numbers.
  EXPECT_EQ(1, Factorial(-5));
  EXPECT_EQ(1, Factorial(-1));
  EXPECT_GT(Factorial(-10), 0);

  // Tests factorial of 0.
  EXPECT_EQ(1, Factorial(0));

  // Tests factorial of positive numbers.
  EXPECT_EQ(1, Factorial(1));
  EXPECT_EQ(2, Factorial(2));
  EXPECT_EQ(6, Factorial(3));
  EXPECT_EQ(40320, Factorial(8));
}

这里IntegerFunctionTest 继承自QuickTest ，内部无其他实现，测试夹具IntegerFunctionTest整个运行时间

class QueueTest : public QuickTest {
 protected:
  void SetUp() override {
    // First, we need to set up the super fixture (QuickTest).
    QuickTest::SetUp();

    // Second, some additional setup for this fixture.
    q1_.Enqueue(1);
    q2_.Enqueue(2);
    q2_.Enqueue(3);
  }

  // By default, TearDown() inherits the behavior of
  // QuickTest::TearDown().  As we have no additional cleaning work
  // for QueueTest, we omit it here.
  //
  // virtual void TearDown() {
  //   QuickTest::TearDown();
  // }

  Queue<int> q0_;
  Queue<int> q1_;
  Queue<int> q2_;
};


// Now, let's write tests using the QueueTest fixture.

// Tests the default constructor.
TEST_F(QueueTest, DefaultConstructor) {
  EXPECT_EQ(0u, q0_.Size());
}

// Tests Dequeue().
TEST_F(QueueTest, Dequeue) {
  int* n = q0_.Dequeue();
  EXPECT_TRUE(n == nullptr);

  n = q1_.Dequeue();
  EXPECT_TRUE(n != nullptr);
  EXPECT_EQ(1, *n);
  EXPECT_EQ(0u, q1_.Size());
  delete n;

  n = q2_.Dequeue();
  EXPECT_TRUE(n != nullptr);
  EXPECT_EQ(2, *n);
  EXPECT_EQ(1u, q2_.Size());
  delete n;
}

QueueTest类继承自QuickTest，并重写SetUp方法，在SetUp方法里调用QuickTest的父类方法，然后对Queue队列做初始化，

TEST_F(QueueTest, DefaultConstructor) {
  EXPECT_EQ(0u, q0_.Size());
}

这里判断q0队列大小是否为0u

TEST_F(QueueTest, Dequeue) {
  int* n = q0_.Dequeue();
  EXPECT_TRUE(n == nullptr);

  n = q1_.Dequeue();   //先出列判断是否为nullptr，在判断数据是否为1，最后判断队列大小是否为0，最后delete删除n
  EXPECT_TRUE(n != nullptr);
  EXPECT_EQ(1, *n);
  EXPECT_EQ(0u, q1_.Size());
  delete n;

  n = q2_.Dequeue();
  EXPECT_TRUE(n != nullptr);
  EXPECT_EQ(2, *n);
  EXPECT_EQ(1u, q2_.Size());
  delete n;
}

q0_.Dequeue队列本来大小为0，出列的数据为nullptr