googletest: performing additional operation if test fail

Question

I'd like to be able to save data to disk in case the test fails. Is there any way to do it within the googletest framework?

TEST_F(test_similarity,are_similar) {

  ASSERT_GT(1e-10,norm(im0,im1));

  // If test fails save images to disk for comparison:
  imwrite("im0.png",im0);
  imwrite("im1.png",im1);
}

Answer 1

There are the Test::HasFailure(), Test::HasNonfatalFailure() and Test::HasFatalFailure() functions, that return true if there was a (fatal/non-fatal) failure. You could use them to check.

TEST_F(test_similarity,are_similar) {

  EXPECT_GT(1e-10,norm(im0,im1)); // Note the change to EXPECT

  // If test fails save images to disk for comparison:
  if(HasFailure()) {  // if not in a TEST, use ::testing::Test::HasFailure()
    imwrite("im0.png",im0);
    imwrite("im1.png",im1);
    FAIL(); //We want to fail fatally; use ADD_FAILURE() to fail non-fatally
  }
}

See https://github.com/google/googletest/blob/master/googletest/docs/advanced.md#checking-for-failures-in-the-current-test for details.