Clean up directories on failure. Closes #58.

tests/conftest.py

@@ -13,12 +13,17 @@ from testing.util import get_resource_path
 
 
 @pytest.yield_fixture
-def empty_git_dir(tmpdir):
+def in_tmpdir(tmpdir):
     with local.cwd(tmpdir.strpath):
-        local['git']['init']()
         yield tmpdir.strpath
 
 
+@pytest.yield_fixture
+def empty_git_dir(in_tmpdir):
+    local['git']['init']()
+    yield in_tmpdir
+
+
 def add_and_commit():
     local['git']['add', '.']()
     local['git']['commit', '-m', 'random commit {0}'.format(time.time())]()

tests/prefixed_command_runner_test.py

@@ -3,7 +3,6 @@ import os
 import mock
 import pytest
 import subprocess
-from plumbum import local
 
 from pre_commit.prefixed_command_runner import _replace_cmd
 from pre_commit.prefixed_command_runner import CalledProcessError
@@ -110,23 +109,20 @@ def test_from_command_runner_preserves_popen(popen_mock, makedirs_mock):
     makedirs_mock.assert_called_once_with('foo/bar/')
 
 
-def test_create_path_if_not_exists(tmpdir):
-    with local.cwd(tmpdir.strpath):
-        instance = PrefixedCommandRunner('foo')
-        assert not os.path.exists('foo')
-        instance._create_path_if_not_exists()
-        assert os.path.exists('foo')
+def test_create_path_if_not_exists(in_tmpdir):
+    instance = PrefixedCommandRunner('foo')
+    assert not os.path.exists('foo')
+    instance._create_path_if_not_exists()
+    assert os.path.exists('foo')
 
 
-def test_exists_does_not_exist(tmpdir):
-    with local.cwd(tmpdir.strpath):
-        assert not PrefixedCommandRunner('.').exists('foo')
+def test_exists_does_not_exist(in_tmpdir):
+    assert not PrefixedCommandRunner('.').exists('foo')
 
 
-def test_exists_does_exist(tmpdir):
-    with local.cwd(tmpdir.strpath):
-        os.mkdir('foo')
-        assert PrefixedCommandRunner('.').exists('foo')
+def test_exists_does_exist(in_tmpdir):
+    os.mkdir('foo')
+    assert PrefixedCommandRunner('.').exists('foo')
 
 
 def test_raises_on_error(popen_mock, makedirs_mock):

tests/util_test.py

@@ -1,11 +1,14 @@
 
 import mock
 import pytest
+import os
+import os.path
 import random
 import sys
 from plumbum import local
 
 from pre_commit.util import cached_property
+from pre_commit.util import clean_path_on_failure
 from pre_commit.util import entry
 from pre_commit.util import memoize_by_cwd
 
@@ -84,3 +87,35 @@ def test_no_arguments_passed_uses_argv(entry_func):
     with mock.patch.object(sys, 'argv', argv):
         ret = entry_func()
         assert ret == argv[1:]
+
+
+def test_clean_on_failure_noop(in_tmpdir):
+    with clean_path_on_failure('foo'): pass
+
+
+def test_clean_path_on_failure_does_nothing_when_not_raising(in_tmpdir):
+    with clean_path_on_failure('foo'):
+        os.mkdir('foo')
+    assert os.path.exists('foo')
+
+
+def test_clean_path_on_failure_cleans_for_normal_exception(in_tmpdir):
+    class MyException(Exception): pass
+
+    with pytest.raises(MyException):
+        with clean_path_on_failure('foo'):
+            os.mkdir('foo')
+            raise MyException
+
+    assert not os.path.exists('foo')
+
+
+def test_clean_path_on_failure_cleans_for_system_exit(in_tmpdir):
+    class MySystemExit(SystemExit): pass
+
+    with pytest.raises(MySystemExit):
+        with clean_path_on_failure('foo'):
+            os.mkdir('foo')
+            raise MySystemExit
+
+    assert not os.path.exists('foo')