Debugging macro to check that a method has returned
The effect of
g_assert_error (err, dom, c) is
the same as
g_assert_true (err != NULL && err->domain
== dom && err->code == c). The advantage of this
macro is that it can produce a message that includes the incorrect
error message and code.
This can only be used to test for a specific error. If you want to
err is set, but don’t care what it’s set to, just use
Available since: 2.20
This function is not directly available to language bindings.