tests: Adapt to pygobject 3.55.0

After upgrading pygobject from 3.54.5 to 3.55.2, Python tests
expecting a process failure on setting an immutable
(G_PARAM_CONSTRUCT_ONLY) property started to fail like this:

    Traceback (most recent call last):
      File "/home/test/libmodulemd-devel/redhat-linux-build/../modulemd/tests/ModulemdTests/defaults.py", line 114, in test_module_name
	self.assertProcessFailure(_set_module_name_to_none, defs)
	~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "/home/test/libmodulemd-devel/modulemd/tests/ModulemdTests/base.py", line 60, in assertProcessFailure
	callable(*args)
	~~~~~~~~^^^^^^^
      File "/home/test/libmodulemd-devel/redhat-linux-build/../modulemd/tests/ModulemdTests/defaults.py", line 43, in _set_module_name_to_none
	defs.props.module_name = None
	^^^^^^^^^^^^^^^^^^^^^^
    TypeError: property 'module-name' can only be set in constructor

The cause was that pygobject-3.55.0 started to raise a Python
TypeError exception instead of calling Glib functions which would fail
on its own depending on Glib warning fatality and Glib version. An example:

    cat /tmp/test.py
    #!/usr/bin/python3

    import gi
    gi.require_version("Modulemd", "2.0")
    from gi.repository import Modulemd

    object = Modulemd.Defaults.new(Modulemd.DefaultsVersionEnum.LATEST, "foo")
    object.props.module_name = "bar"

Before:

    $ /tmp/test.py
    /tmp/test.py:8: Warning: g_object_set_is_valid_property: construct property "module-name" for object 'ModulemdDefaultsV1' can't be set after construction
      object.props.module_name = "bar"

After:

    $ /tmp/test.py
    Traceback (most recent call last):
      File "/tmp/test.py", line 8, in <module>
	object.props.module_name = "bar"
	^^^^^^^^^^^^^^^^^^^^^^^^
    TypeError: property 'module-name' can only be set in constructor

That was an intentional change in pygobject
3b6e4804de4f26cfb9472666f18f44ac731d874c commit (gi: Factor out
pygi_set_property_gvalue_from_property_info). Probably an
optimization.

This patch adjusts the tests to pass if TypeError exception is raised
regardless of Glib warning fatality.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2440570

Author: ppisar

modulemd/tests/ModulemdTests/base.py

@@ -67,6 +67,36 @@ def assertProcessFailure(self, callable, *args):
             if os.WIFSIGNALED(status):
                 raise AssertionError("Child process was unexpectedly aborted")
 
+    def assertTypeExceptionOrProcessFailure(self, callable, *args):
+        """Calls the callable in a subprocess and checks that the process
+        raised a TypeError exception, or was killed depending on Glib warning
+        fatality.
+
+        Since pygobject-3.55.0 setting a G_PARAM_CONSTRUCT_ONLY property
+        raises a Python exception. Old pygobject continues down to Glib
+        which kills the process if Glib warnings a fatal, otherwise Glib
+        warning is printed and the code continues.
+        """
+        pid = os.fork()
+        if pid == 0:
+            try:
+                callable(*args)
+            except TypeError:
+                os._exit(1)
+            os._exit(0)
+        _, status = os.waitpid(pid, 0)
+        if os.WIFEXITED(status) and os.WEXITSTATUS(status) == 1:
+            return
+        if self.warnings_fatal:
+            if not os.WIFSIGNALED(status):
+                raise AssertionError(
+                    "Child process did not raise TypeError "
+                    "exception or was not aborted"
+                )
+        else:
+            if os.WIFSIGNALED(status):
+                raise AssertionError("Child process was unexpectedly aborted")
+
     @property
     def warnings_fatal(self):
         gdebug = os.getenv("G_DEBUG", "").split(",")

modulemd/tests/ModulemdTests/defaults.py

@@ -111,7 +111,9 @@ def test_module_name(self):
         assert defs.get_module_name() == "foo"
 
         # Ensure we cannot set the module_name
-        self.assertProcessFailure(_set_module_name_to_none, defs)
+        self.assertTypeExceptionOrProcessFailure(
+            _set_module_name_to_none, defs
+        )
 
     def test_modified(self):
         defs = Modulemd.Defaults.new(

modulemd/tests/ModulemdTests/profile.py

@@ -94,7 +94,9 @@ def test_get_name(self):
         assert p.get_name() == "testprofile"
         assert p.props.name == "testprofile"
 
-        self.assertProcessFailure(_set_props_name, p, "notadrill")
+        self.assertTypeExceptionOrProcessFailure(
+            _set_props_name, p, "notadrill"
+        )
 
     def test_get_set_description(self):
         p = Modulemd.Profile(name="testprofile")

modulemd/tests/ModulemdTests/servicelevel.py

@@ -103,7 +103,7 @@ def test_get_name(self):
         assert sl.props.name == "foo"
 
         # This property is not writable, make sure it fails to attempt it
-        self.assertProcessFailure(_set_props_name, sl, "bar")
+        self.assertTypeExceptionOrProcessFailure(_set_props_name, sl, "bar")
 
     def test_get_set_eol(self):
         sl = Modulemd.ServiceLevel.new("foo")

modulemd/tests/ModulemdTests/translationentry.py

@@ -172,7 +172,7 @@ def test_get_locale(self):
         assert te.get_locale() == "en_US"
         assert te.props.locale == "en_US"
 
-        self.assertProcessFailure(_set_locale, te)
+        self.assertTypeExceptionOrProcessFailure(_set_locale, te)
 
     def test_get_set_summary(self):
         te = Modulemd.TranslationEntry(locale="en_US")