Merge pull request #622 from pre-commit/staged_files_only_patch_dir_does_not_exist

Do not crash in staged_files_only if patch_dir does not exist

pre_commit/staged_files_only.py

@@ -8,6 +8,7 @@ import time
 
 from pre_commit.util import CalledProcessError
 from pre_commit.util import cmd_output
+from pre_commit.util import mkdirp
 
 
 logger = logging.getLogger('pre_commit')
@@ -43,6 +44,7 @@ def staged_files_only(patch_dir):
             'Stashing unstaged files to {}.'.format(patch_filename),
         )
         # Save the current unstaged changes as a patch
+        mkdirp(patch_dir)
         with io.open(patch_filename, 'wb') as patch_file:
             patch_file.write(diff_stdout_binary)
 

tests/staged_files_only_test.py

@@ -75,6 +75,15 @@ def test_foo_something_unstaged(foo_staged, patch_dir):
     _test_foo_state(foo_staged, 'herp\nderp\n', 'AM')
 
 
+def test_does_not_crash_patch_dir_does_not_exist(foo_staged, patch_dir):
+    with io.open(foo_staged.foo_filename, 'w') as foo_file:
+        foo_file.write('hello\nworld\n')
+
+    shutil.rmtree(patch_dir)
+    with staged_files_only(patch_dir):
+        pass
+
+
 def test_something_unstaged_ext_diff_tool(foo_staged, patch_dir, tmpdir):
     diff_tool = tmpdir.join('diff-tool.sh')
     diff_tool.write('#!/usr/bin/env bash\necho "$@"\n')