How to Install and Get Started with Google Test

Google Test is a C++ unit testing framework developed by Google. It allows you to write automated tests, check conditions, group tests, use fixtures, and more.

Installation

Dependencies: Compiler: Clang, GNU GCC, or MSVC

On Windows

Via WinGet

winget install --id=Google.GoogleDrive  -e
`

On Ubuntu

sudo apt install googletest libgtest-dev

On Arch

sudo pacman -S googletest

Basic Example

#include <gtest/gtest.h>

constexpr auto sum = [](int a, int b){ 
  return a + b;
};

TEST(sum_test, sum_positive) {
  EXPECT_EQ(sum(2, 3), 5);
}

TEST(sum_test, sum_negative) {
  EXPECT_EQ(sum(-2, -3), -5);
}

int main(int argc, char **argv){
  ::testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}

Compile:

g++ test.cpp -lgtest

After running ./a.out:

[==========] Running 2 tests from 1 test suite.
[----------] Global test environment set-up.
[----------] 2 tests from sum_test
[ RUN      ] sum_test.sum_positive
[       OK ] sum_test.sum_positive (0 ms)
[ RUN      ] sum_test.sum_negative
[       OK ] sum_test.sum_negative (0 ms)
[----------] 2 tests from sum_test (0 ms total)

[----------] Global test environment tear-down
[==========] 2 tests from 1 test suite ran. (0 ms total)
[  PASSED  ] 2 tests.

EXPECT_EQ(x, y) – Checks for equality
ASSERT_TRUE(cond) – Fails and stops execution if the condition is false
TEST_F – Uses fixtures (setup/teardown)

If we change the sum_positive line to use a float and a negative number: EXPECT_EQ(sum(2.f, -3), 5);

Failures will be reported:

[==========] Running 2 tests from 1 test suite.
[----------] Global test environment set-up.
[----------] 2 tests from sum_test
[ RUN      ] sum_test.sum_positive
test.cpp:8: Failure
Expected equality of these values:
  sum(2.f, -3)
    Which is: -1
  5

[  FAILED  ] sum_test.sum_positive (0 ms)
[ RUN      ] sum_test.sum_negative
[       OK ] sum_test.sum_negative (0 ms)
[----------] 2 tests from sum_test (0 ms total)

[----------] Global test environment tear-down
[==========] 2 tests from 1 test suite ran. (0 ms total)
[  PASSED  ] 1 test.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] sum_test.sum_positive

 1 FAILED TEST