When using helper functions in gtest which use the ASSERT_ or EXPECT_ macros then that helper function has to be void. However, I'd like to check for those errors within the calling test-code as well.
There is the ASSERT_NO_FATAL_FAILURE macro which helps to stop the calling code in case an ASSERT_ was triggered, but I'd like to extend that with proper handling of EXPECT_ failures (read: NonFatalFailures) as well. Here's what I got so far:
#include <gtest/gtest.h>
// A void test-function using ASSERT_ or EXPECT_ calls should be encapsulated by this macro.
// Example: CHECK_FOR_FAILURES(MyCheckForEquality(lhs, rhs))
#define CHECK_FOR_FAILURES(statement) \
ASSERT_NO_FATAL_FAILURE((statement)); \
EXPECT_FALSE(HasNonfatalFailure())
void TestHelperFunction(bool givenAssert, int givenExpect)
{
ASSERT_TRUE(givenAssert); // note: this is line 11 in my code
EXPECT_EQ(givenExpect, 0); // note: this is line 12 in my code
}
TEST(FailureInFunctionTestNoChecks, noChecks)
{
// note: this is line 17 in my code
TestHelperFunction(true, 0);
TestHelperFunction(true, 1);
for (int i = 0; i < 3; ++i)
{
TestHelperFunction(true, i);
}
TestHelperFunction(false, 1);
TestHelperFunction(true, 2);
}
TEST(FailureInFunctionTestWithChecks, withChecks)
{
// note: this is line 30 in my code
CHECK_FOR_FAILURES(TestHelperFunction(true, 0)) << "\n All good - will NOT be seen! \n";
CHECK_FOR_FAILURES(TestHelperFunction(true, 1)) << "\n optional msg: First Expect failed \n";
for (int i = 0; i < 3; ++i)
{
CHECK_FOR_FAILURES(TestHelperFunction(true, i)) << "\n optional msg: Expect failed for i=" << i << "\n";
}
CHECK_FOR_FAILURES(TestHelperFunction(false, 1)) << "this message will NOT be seen due to the assert";
CHECK_FOR_FAILURES(TestHelperFunction(true, 2)) << "\n will not be seen because assert stops the test \n";
}
// This test creates the following output:
// Note: Google Test filter = *FailureInFunctionTest*
// [==========] Running 2 tests from 2 test cases.
// [----------] Global test environment set-up.
// [----------] 1 test from FailureInFunctionTestNoChecks
// [ RUN ] FailureInFunctionTestNoChecks.noChecks
// ./checked_test_failure.cpp:12: Failure
// Expected equality of these values:
// givenExpect
// Which is: 1
// 0
// ./checked_test_failure.cpp:12: Failure
// Expected equality of these values:
// givenExpect
// Which is: 1
// 0
// ./checked_test_failure.cpp:12: Failure
// Expected equality of these values:
// givenExpect
// Which is: 2
// 0
// ./checked_test_failure.cpp:11: Failure
// Value of: givenAssert
// Actual: false
// Expected: true
// ./checked_test_failure.cpp:12: Failure
// Expected equality of these values:
// givenExpect
// Which is: 2
// 0
// [ FAILED ] FailureInFunctionTestNoChecks.noChecks (0 ms)
// [----------] 1 test from FailureInFunctionTestNoChecks (0 ms total)
//
// [----------] 1 test from FailureInFunctionTestWithChecks
// [ RUN ] FailureInFunctionTestWithChecks.withChecks
// ./checked_test_failure.cpp:12: Failure
// Expected equality of these values:
// givenExpect
// Which is: 1
// 0
// ./checked_test_failure.cpp:32: Failure
// Value of: HasNonfatalFailure()
// Actual: true
// Expected: false
//
// optional msg: First Expect failed
//
// ./checked_test_failure.cpp:35: Failure
// Value of: HasNonfatalFailure()
// Actual: true
// Expected: false
//
// optional msg: Expect failed for i=0
//
// ./checked_test_failure.cpp:12: Failure
// Expected equality of these values:
// givenExpect
// Which is: 1
// 0
// ./checked_test_failure.cpp:35: Failure
// Value of: HasNonfatalFailure()
// Actual: true
// Expected: false
//
// optional msg: Expect failed for i=1
//
// ./checked_test_failure.cpp:12: Failure
// Expected equality of these values:
// givenExpect
// Which is: 2
// 0
// ./checked_test_failure.cpp:35: Failure
// Value of: HasNonfatalFailure()
// Actual: true
// Expected: false
//
// optional msg: Expect failed for i=2
//
// ./checked_test_failure.cpp:11: Failure
// Value of: givenAssert
// Actual: false
// Expected: true
// ./checked_test_failure.cpp:37: Failure
// Expected: (TestHelperFunction(false, 1)) doesn't generate new fatal failures in the current thread.
// Actual: it does.
// [ FAILED ] FailureInFunctionTestWithChecks.withChecks (1 ms)
// [----------] 1 test from FailureInFunctionTestWithChecks (1 ms total)
//
// [----------] Global test environment tear-down
// [==========] 2 tests from 2 test cases ran. (1 ms total)
// [ PASSED ] 0 tests.
// [ FAILED ] 2 tests, listed below:
// [ FAILED ] FailureInFunctionTestNoChecks.noChecks
// [ FAILED ] FailureInFunctionTestWithChecks.withChecks
//
// 2 FAILED TESTS
//
As you can see from the output: Using the new 'CHECK_FOR_FAILURES' macro improves the test-output: It tells you which line caused a failure and it prevents executing a test after an assert was hit.
However, using 'HasNonfatalFailure()' is not good enough as you can see in the output for i=0. The reason is there was a non-fatal error already and for i=0 there was no NEW non-fatal error but the HasNonfatalFailure() returns true due to the old one.. :-(
Any idea how I can get rid of the wrong i=0 output?
An obvious way using the suggestion of gtest docs is the following, but I'd rather do it without custom messages or the SCOPED_TRACE() macro
#include <gtest/gtest.h>
// A void test-function using ASSERT_ or EXPECT_ calls with a custom message should be encapsulated
// by this macro. Example: CHECK_FOR_FAILURES_MSG(MyCheckForEquality(counter, 42), "for counter=42")
#define CHECK_FOR_FAILURES_MSG(statement, message) \
{ \
SCOPED_TRACE(message); \
ASSERT_NO_FATAL_FAILURE((statement)); \
}
// A void test-function using ASSERT_ or EXPECT_ calls should be encapsulated by this macro.
// Example: CHECK_FOR_FAILURES(MyCheckForEquality(lhs, rhs))
#define CHECK_FOR_FAILURES(statement) CHECK_FOR_FAILURES_MSG(statement, " <-- line of failure\n")
void TestHelperFunction(bool givenAssert, int givenExpect)
{
ASSERT_TRUE(givenAssert); // note: this is line 17 in my code
EXPECT_EQ(givenExpect, 0); // note: this is line 18 in my code
}
TEST(FailureInFunctionTestNoChecks, noChecks)
{
// note: this is line 23 in my code
TestHelperFunction(true, 0);
TestHelperFunction(true, 1);
for (int i = 0; i < 3; ++i)
{
TestHelperFunction(true, i);
}
TestHelperFunction(false, 1);
TestHelperFunction(true, 2);
}
TEST(FailureInFunctionTestWithChecks, withChecks)
{
// note: this is line 36 in my code
CHECK_FOR_FAILURES(TestHelperFunction(true, 0));
CHECK_FOR_FAILURES(TestHelperFunction(true, 1));
for (int i = 0; i < 3; ++i)
{
CHECK_FOR_FAILURES_MSG(TestHelperFunction(true, i), "for i=" + std::to_string(i) + "\n");
}
CHECK_FOR_FAILURES(TestHelperFunction(false, 1));
CHECK_FOR_FAILURES(TestHelperFunction(true, 2));
}
// Note: Google Test filter = *FailureInFunction*
//[==========] Running 2 tests from 2 test cases.
//[----------] Global test environment set-up.
//[----------] 1 test from FailureInFunctionTestNoChecks
//[ RUN ] FailureInFunctionTestNoChecks.noChecks
//./checked_test_failure.cpp:18: Failure
//Expected equality of these values:
// givenExpect
// Which is: 1
// 0
//./checked_test_failure.cpp:18: Failure
//Expected equality of these values:
// givenExpect
// Which is: 1
// 0
//./checked_test_failure.cpp:18: Failure
//Expected equality of these values:
// givenExpect
// Which is: 2
// 0
//./checked_test_failure.cpp:17: Failure
//Value of: givenAssert
// Actual: false
//Expected: true
//./checked_test_failure.cpp:18: Failure
//Expected equality of these values:
// givenExpect
// Which is: 2
// 0
//[ FAILED ] FailureInFunctionTestNoChecks.noChecks (0 ms)
//[----------] 1 test from FailureInFunctionTestNoChecks (0 ms total)
//
//[----------] 1 test from FailureInFunctionTestWithChecks
//[ RUN ] FailureInFunctionTestWithChecks.withChecks
//./checked_test_failure.cpp:18: Failure
//Expected equality of these values:
// givenExpect
// Which is: 1
// 0
//Google Test trace:
//./checked_test_failure.cpp:38: <-- line of failure
//
//./checked_test_failure.cpp:18: Failure
//Expected equality of these values:
// givenExpect
// Which is: 1
// 0
//Google Test trace:
//./checked_test_failure.cpp:41: for i=1
//
//./checked_test_failure.cpp:18: Failure
//Expected equality of these values:
// givenExpect
// Which is: 2
// 0
//Google Test trace:
//./checked_test_failure.cpp:41: for i=2
//
//./checked_test_failure.cpp:17: Failure
//Value of: givenAssert
// Actual: false
//Expected: true
//Google Test trace:
//./checked_test_failure.cpp:43: <-- line of failure
//
//./checked_test_failure.cpp:43: Failure
//Expected: (TestHelperFunction(false, 1)) doesn't generate new fatal failures in the current thread.
// Actual: it does.
//Google Test trace:
//./checked_test_failure.cpp:43: <-- line of failure
//
//[ FAILED ] FailureInFunctionTestWithChecks.withChecks (0 ms)
//[----------] 1 test from FailureInFunctionTestWithChecks (0 ms total)
//
//[----------] Global test environment tear-down
//[==========] 2 tests from 2 test cases ran. (0 ms total)
//[ PASSED ] 0 tests.
//[ FAILED ] 2 tests, listed below:
//[ FAILED ] FailureInFunctionTestNoChecks.noChecks
//[ FAILED ] FailureInFunctionTestWithChecks.withChecks
//
// 2 FAILED TESTS
//