tests.unit.config: Make sure volume order is preserved.

Signed-off-by: Antony MECHIN <[email protected]>

tests/unit/config/config_test.py

@@ -8,6 +8,7 @@ import os
 import shutil
 import tempfile
 from operator import itemgetter
+from random import shuffle
 
 import py
 import pytest
@@ -3536,6 +3537,13 @@ class VolumeConfigTest(unittest.TestCase):
         ).services[0]
         assert d['volumes'] == [VolumeSpec.parse('/host/path:/container/path')]
 
+    @pytest.mark.skipif(IS_WINDOWS_PLATFORM, reason='posix paths')
+    def test_volumes_order_is_preserved(self):
+        volumes = ['/{0}:/{0}'.format(i) for i in range(0, 6)]
+        shuffle(volumes)
+        cfg = make_service_dict('foo', {'build': '.', 'volumes': volumes})
+        assert cfg['volumes'] == volumes
+
     @pytest.mark.skipif(IS_WINDOWS_PLATFORM, reason='posix paths')
     @mock.patch.dict(os.environ)
     def test_volume_binding_with_home(self):