// Returns n! (the factorial of n).  For negative n, n! is defined to be 1.//int Factorial(int n) {	int result = 1;	for (int i = 1; i <= n; i++) {		result *= i;	}	return result;}// Returns true iff n is a prime number.bool IsPrime(int n) {	// Trivial case 1: small numbers	if (n <= 1) return false;	// Trivial case 2: even numbers	if (n % 2 == 0) return n == 2;	// Now, we have that n is odd and n >= 3.	// Try to divide n by every odd number i, starting from 3	for (int i = 3; ; i += 2) {		// We only have to try i up to the squre root of n		if (i > n / i) break;		// Now, we have i <= n/i < n.		// If n is divisible by i, n is not prime.		if (n % i == 0) return false;	}	// n has no integer factor in the range (1, n), and thus is prime.	return true;}

extern int Factorial(int n);extern bool IsPrime(int n);// Tests Factorial().// Tests factorial of negative numbers.TEST(FactorialTest, Negative) {	// This test is named "Negative", and belongs to the "FactorialTest"	// test case.	EXPECT_EQ(1, Factorial(-5));	EXPECT_EQ(2, Factorial(-1)); //如果是ASSERT_EQ，后边的EXPECT_GT将不在执行；如果是EXPECT_EQ，后边的测试EXPECT_GT继续执行	EXPECT_GT(Factorial(-10), 0);	ASSERT_EQ(3, Factorial(-1));	// <TechnicalDetails>	//	// EXPECT_EQ(expected, actual) is the same as	//	//   EXPECT_TRUE((expected) == (actual))	//	// except that it will print both the expected value and the actual	// value when the assertion fails.  This is very helpful for	// debugging.  Therefore in this case EXPECT_EQ is preferred.	//	// On the other hand, EXPECT_TRUE accepts any Boolean expression,	// and is thus more general.	//	// </TechnicalDetails>}// Tests factorial of 0.TEST(FactorialTest, Zero) {	EXPECT_EQ(1, Factorial(0));}// Tests factorial of positive numbers.TEST(FactorialTest, Positive) {	EXPECT_EQ(1, Factorial(1));	EXPECT_EQ(2, Factorial(2));	EXPECT_EQ(6, Factorial(3));	EXPECT_EQ(40320, Factorial(8));}// Tests IsPrime()// Tests negative input.TEST(IsPrimeTest, Negative) {	// This test belongs to the IsPrimeTest test case.	EXPECT_FALSE(IsPrime(-1));	EXPECT_FALSE(IsPrime(-2));	EXPECT_FALSE(IsPrime(INT_MIN));}// Tests some trivial cases.TEST(IsPrimeTest, Trivial) {	EXPECT_FALSE(IsPrime(0));	EXPECT_FALSE(IsPrime(1));	EXPECT_TRUE(IsPrime(2));	EXPECT_TRUE(IsPrime(3));}// Tests positive input.TEST(IsPrimeTest, Positive) {	EXPECT_FALSE(IsPrime(4));	EXPECT_TRUE(IsPrime(5));	EXPECT_FALSE(IsPrime(6));	EXPECT_TRUE(IsPrime(23));}// Step 3. Call RUN_ALL_TESTS() in main().//// We do this by linking in src/gtest_main.cc file, which consists of// a main() function which calls RUN_ALL_TESTS() for us.//// This runs all the tests you‘ve defined, prints the result, and// returns 0 if successful, or 1 otherwise.//// Did you notice that we didn‘t register the tests?  The// RUN_ALL_TESTS() macro magically knows about all the tests we// defined.  Isn‘t this convenient?

#include <limits.h>#include "sample1.h"#include <gtest/gtest.h>  

TEST(FactorialTest, Negative) {  // This test is named "Negative", and belongs to the "FactorialTest"  // test case.  EXPECT_EQ(1, Factorial(-5));  EXPECT_EQ(2, Factorial(-1)); //如果是ASSERT_EQ，后边的EXPECT_GT将不在执行；如果是EXPECT_EQ，后边的测试EXPECT_GT继续执行  EXPECT_GT(Factorial(-10), 0);  EXPECT_TRUE(2 == Factorial(-7));//这个错误失败信息打印的是true或false，不会打印值  ASSERT_EQ(3, Factorial(-1));} 

int main(int argc, char **argv) {//printf("Running main() from gtest_main.cc\n");testing::InitGoogleTest(&argc,argv);return RUN_ALL_TESTS();}