谷歌死亡测试没有消息

Question

I am trying the Google Test framework on Linux and GCC10.

Basic tests work fine, however there is something about death tests I don't get. Death test macros like EXPECT_DEBUG_DEATH have a second parameter ("matcher") which should be a regex string that is compared to whatever has been printed to stderr before the test finishes by death of the process.

TEST(MyDeathTests, MyDeathTest)
{
   EXPECT_DEBUG_DEATH({ assert(false); }, "");
   EXPECT_DEBUG_DEATH({ fprintf(stderr, "Bye\n"); fflush(stderr); exit(1); }, "");
   EXPECT_DEBUG_DEATH({ std::cerr << "Darn" << std::endl << std::flush; std::abort(); }, "");
}

Death is detected correctly. But tests succeed only when using an empty matcher string as you can see in the snippet above. "Actual msg" in the test output is always empty. I tried some variants with exit() , stdout , stderr and C output functions but nothing worked.

Any ideas why no death messages are received?

Answer 1

Turned out there have been two misunderstandings on my side:

1. The matcher-strings are sub-string patterns. This means an empty matcher-string matches anything (not only empty messages as assumed by me).
2. Actual msg did not really display an empty message string. It only uses a weird formatting. Google test adds a line break followed by [ DEATH ] after Actual msg before printing the error message. This made me think I would see the un-caught error output on the console but actually it was the correctly detected Actual msg .

Knowing those facts, everything works as expected.