[meld] test: Add a conftest to get around not having default icon theme in CI

[Kai Willadsen <kaiw src gnome org>]

commit c11de6c3646d7719bcf3944fbace14c8c6784530
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sat Jan 20 07:06:25 2018 +1000

    test: Add a conftest to get around not having default icon theme in CI

 test/conftest.py                 | 16 ++++++++++++++++
 test/test_gutterrendererchunk.py |  8 +++++---
 2 files changed, 21 insertions(+), 3 deletions(-)
---
diff --git a/test/conftest.py b/test/conftest.py
new file mode 100644
index 00000000..94688e62
--- /dev/null
+++ b/test/conftest.py
@@ -0,0 +1,16 @@
+
+from unittest import mock
+
+import pytest
+
+
+@pytest.fixture(autouse=True)
+def default_icon_theme():
+    # Our tests need to run on a system with no default display, so all
+    # our display-specific get_default() stuff will break.
+
+    from gi.repository import Gtk
+    with mock.patch(
+            'gi.repository.Gtk.IconTheme.get_default',
+            mock.Mock(spec=Gtk.IconTheme.get_default)):
+        yield
diff --git a/test/test_gutterrendererchunk.py b/test/test_gutterrendererchunk.py
index d0c05054..bd1e2580 100644
--- a/test/test_gutterrendererchunk.py
+++ b/test/test_gutterrendererchunk.py
@@ -3,9 +3,7 @@ from unittest import mock
 
 import pytest
 
-import meld.gutterrendererchunk
-from meld.gutterrendererchunk import GutterRendererChunkAction
-from meld.const import MODE_REPLACE, MODE_DELETE, MODE_INSERT
+from meld.const import MODE_DELETE, MODE_INSERT, MODE_REPLACE
 from meld.matchers.myers import DiffChunk
 
 
@@ -57,6 +55,10 @@ def make_chunk(chunk_type):
     # TODO: Add tests for conflict chunks
 ])
 def test_classify_change_actions(mode, editable, chunk, expected_action):
+
+    import meld.gutterrendererchunk
+    from meld.gutterrendererchunk import GutterRendererChunkAction
+
     filediff = mock.MagicMock()
     meld.gutterrendererchunk.meldsettings = mock.MagicMock(style_scheme=None)
     GutterRendererChunkAction.on_setting_changed = mock.MagicMock()