1 files changed, 23 insertions, 0 deletions
diff --git a/tests/languages/docker_test.py b/tests/languages/docker_test.py
new file mode 100644
index 0000000..171a3f7
--- /dev/null
+++ b/tests/languages/docker_test.py
@@ -0,0 +1,23 @@
+from unittest import mock
+
+from pre_commit.languages import docker
+from pre_commit.util import CalledProcessError
+
+
+def test_docker_is_running_process_error():
+    with mock.patch(
+        'pre_commit.languages.docker.cmd_output_b',
+        side_effect=CalledProcessError(1, (), 0, b'', None),
+    ):
+        assert docker.docker_is_running() is False
+
+
+def test_docker_fallback_user():
+    def invalid_attribute():
+        raise AttributeError
+    with mock.patch.multiple(
+        'os', create=True,
+        getuid=invalid_attribute,
+        getgid=invalid_attribute,
+    ):
+        assert docker.get_docker_user() == '1000:1000'