tests: Run each datetime test under Xvfb

That way, gtk_init() cannot fail.

tests/datetime/meson.build

@@ -8,6 +8,8 @@ test_units = [
 includes = [top_inc, include_directories('../../panels/datetime')]
 env = [
   'G_MESSAGES_DEBUG=all',
+          'BUILDDIR=' + meson.current_build_dir(),
+      'TOP_BUILDDIR=' + meson.build_root()
 ]
 cflags = [
   '-DTEST_SRCDIR="@0@"'.format(meson.current_source_dir()),
@@ -23,7 +25,11 @@ foreach unit: test_units
               link_with : [datetime_panel_lib],
                  c_args : cflags
   )
-
-  test(unit, exe, env: env)
 endforeach
 
+test(
+  'test-datetime',
+  find_program('test-datetime.py'),
+      env : env,
+  timeout : 10
+)

tests/datetime/test-datetime.py

@@ -0,0 +1,54 @@
+#!/usr/bin/python3
+# Copyright © 2018 Red Hat, Inc
+#             2018 Endless Mobile, Inc
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, see <http://www.gnu.org/licenses/>.
+#
+# Authors: Benjamin Berg <bberg@redhat.com>
+#          Georges Basile Stavracas Neto <georges@endlessm.com>
+
+import os
+import sys
+import unittest
+
+try:
+    import dbusmock
+except ImportError:
+    sys.stderr.write('You need python-dbusmock (http://pypi.python.org/pypi/python-dbusmock) for this test suite.\n')
+    sys.exit(1)
+
+# Add the shared directory to the search path
+sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'shared'))
+
+from gtest import GTest
+from x11session import X11SessionTestCase
+
+BUILDDIR = os.environ.get('BUILDDIR', os.path.join(os.path.dirname(__file__)))
+
+
+class EndianessTestCase(X11SessionTestCase, GTest):
+    g_test_exe = os.path.join(BUILDDIR, 'test-endianess')
+
+
+class TimezoneTestCase(X11SessionTestCase, GTest):
+    g_test_exe = os.path.join(BUILDDIR, 'test-timezone')
+
+
+class TimezoneGfxTestCase(X11SessionTestCase, GTest):
+    g_test_exe = os.path.join(BUILDDIR, 'test-timezone-gfx')
+
+
+if __name__ == '__main__':
+    _test = unittest.TextTestRunner(stream=sys.stdout, verbosity=2)
+    unittest.main(testRunner=_test)