How to send custom message in Google C++ Testing Framework?

There is no way of doing it cleanly in the current version of gtest. I looked at the code, and the only text output (wrapped in gtest "Messages") is shown if you fail a test.

However, at some point, gtest starts printf'ing to the screen, and you can leverage the level above that to get colors that are platform independent.

Here's a hacked macro to do what you want. This uses the gtest internal text coloring. Of course the internal:: namespace should be sounding off warning bells, but hey, it works.

Usage:

TEST(pa_acq,Foo)
{
  // C style
  PRINTF("Hello world \n");

  // or C++ style

  TEST_COUT << "Hello world" << std::endl;
}

Output:

Code:

namespace testing
{
 namespace internal
 {
  enum GTestColor {
      COLOR_DEFAULT,
      COLOR_RED,
      COLOR_GREEN,
      COLOR_YELLOW
  };

  extern void ColoredPrintf(GTestColor color, const char* fmt, ...);
 }
}
#define PRINTF(...)  do { testing::internal::ColoredPrintf(testing::internal::COLOR_GREEN, "[          ] "); testing::internal::ColoredPrintf(testing::internal::COLOR_YELLOW, __VA_ARGS__); } while(0)

// C++ stream interface
class TestCout : public std::stringstream
{
public:
    ~TestCout()
    {
        PRINTF("%s",str().c_str());
    }
};

#define TEST_COUT  TestCout()

The gtest macros return a stream for outputting diagnostic messages when a test fails.

EXPECT_TRUE(false) << "diagnostic message";