Testing with GoogleTest

Testing with GoogleTest

Introduction

For testing the correctness of our functions in t8code, we use the GoogleTest framework. This framework allows us to test code sections independently for several parameters and properties of t8code. The task is finding code errors in the early development of new t8code sections. You get more information and guidelines about the implementation of GoogleTests at GoogleTest User’s Guide.

Guidelines

A test should only check one property of the code. A common test is the Parameterized Test. These tests allow you to test code sections over a range of variables. In our case, this is the go-to when testing element-functions for all available elements in a scheme. The tests should not test specific cases, but should also be applicable to code extensions. Keep the code simple and understandable. For this you should follow our Coding Guideline · DLR-AMR/t8code.

Output

The test should not print an output apart from error-messages of failing tests. Other messages should only print a message in debug configuration. Use the command t8_debugf to print such messages.

Assertions and expectations

Various checks can be applied to the code. There are assertions and expectations. The expectations are called by EXPECT_*. If an expectation will fail, the current test (or function) will not be aborted. By using an assertion, which is called by ASSERT_*, a test (or a function) will abort directly. Note that if a function will be aborted, that the test will not be aborted. It is not possible to use assertions in functions, that have a return value. The most common assertions and expectations are:

• EXPECT/ ASSERT_TRUE
• EXPECT/ ASSERT_FALSE
• EXPECT/ ASSERT_EQ (equal)
• EXPECT/ ASSERT_NE (not equal)
• EXPECT/ ASSERT_ LT (less than)
• EXPECT/ ASSERT_LE (less or equal)
• EXPECT/ ASSERT_GT (greater than)
• EXPECT/ ASSERT_GE (greater or equal) More checks on: Assertions Reference | GoogleTest.

Choose the most fitting check for your test. Use ASSERT_TRUE, ASSERT_FALSE, EXPECT_TRUE or EXPECT_FALSE only if no other check can be applied.

Failure message

If a test fails we would like to know more about the reason for aborting. A failure message, which is connected with an assertion (or expectation) by using << “my_string” throws an information message if the test fails at this point.

ASSERT_TRUE(t8_cmesh_is_commited(cmesh)) <<"Cmesh commit failed.”;
ASSERT_EQ(dual_face, checkface) << “Wrong dual face. Expected “ << checkface << “ got ” << dual_face;