GTest - cheat sheet

A quick reference on parameterized testing and some useful commands in Google Test.

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Parameterized testing

In GTest, parameterized testing allows the same test to be executed with different inputs. The following example demonstrates testing the isBalanced() method of a Parentheses class using various input strings.

struct ParenthesesClassFixture : public testing::TestWithParam<std::pair<std::string, bool>> {
  Parentheses p;

  void checkIsBalanceMethod(const std::string& result, bool expectedResult) {
    EXPECT_EQ(p.isBalanced(result), expectedResult);
  }
};

TEST_P(ParenthesesClassFixture, givenEmptyStringWhenIsBalancedIsCalledThenResultIsTrue) {
  auto [result, expectedResult] = GetParam();
  checkIsBalanceMethod(result, expectedResult);
}

INSTANTIATE_TEST_SUITE_P(MyInstantiationName,
                         ParenthesesClassFixture,
                         testing::Values(
                             std::make_pair("", true),
                             std::make_pair("", false),
                             std::make_pair("({)}", false),
                             std::make_pair("[({})]", true),
                             std::make_pair("{}([])", true),
                             std::make_pair("{()}[[{}]]", true),
                             std::make_pair("{(([]))]((", false)
                         )
);

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Important test flags

Command	Description
--gtest_filter=<TEST_NAME>	Runs only tests with the specified name.
--gtest_repeat=<COUNT>	Repeats the tests a specified number of times (useful for investigating undefined behavior).
--gtest_shuffle	Shuffles the order of tests, so they are not executed in the order they appear in the source file.

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Reference

• GTest documentation