testTrapSubprocessWithEnvp

Respawns the test program to run only test_path in a subprocess with the given envp environment.

This can be used for a test case that might not return, or that might abort.

If test_path is null then the same test is re-run in a subprocess. You can use [glib.global.testSubprocess] to determine whether the test is in a subprocess or not.

test_path can also be the name of the parent test, followed by "/subprocess/" and then a name for the specific subtest (or just ending with "/subprocess" if the test only has one child test); tests with names of this form will automatically be skipped in the parent process.

If envp is null, the parent process’ environment will be inherited.

If usec_timeout is non-0, the test subprocess is aborted and considered failing if its run time exceeds it.

The subprocess behavior can be configured with the #GTestSubprocessFlags flags.

You can use methods such as g_test_trap_assert_passed(), g_test_trap_assert_failed(), and g_test_trap_assert_stderr() to check the results of the subprocess. (But note that g_test_trap_assert_stdout() and g_test_trap_assert_stderr() cannot be used if test_flags specifies that the child should inherit the parent stdout/stderr.)

If your main () needs to behave differently in the subprocess, you can call [glib.global.testSubprocess] (after calling [glib.global.testInit]) to see whether you are in a subprocess.

Internally, this function tracks the child process using [glib.global.childWatchSourceNew], so your process must not ignore SIGCHLD, and must not attempt to watch or wait for the child process via another mechanism.

The following example tests that calling my_object_new(1000000) will abort with an error message.

static void
 test_create_large_object (void)
 {
   if (g_test_subprocess ())
     {
       my_object_new (1000000);
       return;
     }

   // Reruns this same test in a subprocess
   g_test_trap_subprocess (NULL, 0, G_TEST_SUBPROCESS_DEFAULT);
   g_test_trap_assert_failed ();
   g_test_trap_assert_stderr ("*ERROR*too large*");
 }

 static void
 test_different_username (void)
 {
   if (g_test_subprocess ())
     {
       // Code under test goes here
       g_message ("Username is now simulated as %s", g_getenv ("USER"));
       return;
     }

   // Reruns this same test in a subprocess
   g_autoptr(GStrv) envp = g_get_environ ();
   envp = g_environ_setenv (g_steal_pointer (&envp), "USER", "charlie", TRUE);
   g_test_trap_subprocess_with_envp (NULL, envp, 0, G_TEST_SUBPROCESS_DEFAULT);
   g_test_trap_assert_passed ();
   g_test_trap_assert_stdout ("Username is now simulated as charlie");
 }

 int
 main (int argc, char **argv)
 {
   g_test_init (&argc, &argv, NULL);

   g_test_add_func ("/myobject/create-large-object",
                    test_create_large_object);
   g_test_add_func ("/myobject/different-username",
                    test_different_username);
   return g_test_run ();
 }