1 files changed, 44 insertions, 0 deletions
diff --git a/tests/test_os_helpers.py b/tests/test_os_helpers.py
new file mode 100644
index 0000000..220e114
--- /dev/null
+++ b/tests/test_os_helpers.py
@@ -0,0 +1,44 @@
+from alembic import util
+from alembic.testing import assert_raises_message
+from alembic.testing.fixtures import TestBase
+
+try:
+    from unittest.mock import patch
+except ImportError:
+    from mock import patch  # noqa
+
+
+class TestHelpers(TestBase):
+
+    def test_edit_with_user_editor(self):
+        test_environ = {
+            'EDITOR': 'myvim',
+            'PATH': '/usr/bin'
+        }
+
+        with patch('alembic.util.os_helpers.check_call') as check_call, \
+                patch('alembic.util.os_helpers.exists') as exists:
+            exists.side_effect = lambda fname: fname == '/usr/bin/myvim'
+            util.open_in_editor('myfile', test_environ)
+            check_call.assert_called_with(['/usr/bin/myvim', 'myfile'])
+
+    def test_edit_with_default_editor(self):
+        test_environ = {}
+
+        with patch('alembic.util.os_helpers.check_call') as check_call, \
+                patch('alembic.util.os_helpers.exists') as exists:
+            exists.side_effect = lambda fname: fname == '/usr/bin/vim'
+            util.open_in_editor('myfile', test_environ)
+            check_call.assert_called_with(['/usr/bin/vim', 'myfile'])
+
+    def test_edit_with_missing_editor(self):
+        test_environ = {}
+        with patch('alembic.util.os_helpers.check_call'), \
+                patch('alembic.util.os_helpers.exists') as exists:
+            exists.return_value = False
+            assert_raises_message(
+                OSError,
+                'EDITOR',
+                util.open_in_editor,
+                'myfile',
+                test_environ)