Simplify the tests

testing/util.py

@@ -1,7 +1,6 @@
 from __future__ import absolute_import
 from __future__ import unicode_literals
 
-import contextlib
 import io
 import os.path
 
@@ -9,16 +8,6 @@ import os.path
 TESTING_DIR = os.path.abspath(os.path.dirname(__file__))
 
 
-@contextlib.contextmanager
-def cwd(path):
-    pwd = os.getcwd()
-    os.chdir(path)
-    try:
-        yield
-    finally:
-        os.chdir(pwd)
-
-
 def get_resource_path(path):
     return os.path.join(TESTING_DIR, 'resources', path)
 

tests/autopep8_wrapper_test.py

@@ -1,8 +1,6 @@
 from __future__ import absolute_import
 from __future__ import unicode_literals
 
-import io
-
 import pytest
 
 from pre_commit_hooks.autopep8_wrapper import main
@@ -16,20 +14,15 @@ from pre_commit_hooks.autopep8_wrapper import main
     ),
 )
 def test_main_failing(tmpdir, input_src, expected_ret, output_src):
-    filename = tmpdir.join('test.py').strpath
+    path = tmpdir.join('test.py')
-    with io.open(filename, 'w') as file_obj:
+    path.write(input_src)
-        file_obj.write(input_src)
+    ret = main([path.strpath, '-i', '-v'])
-    ret = main([filename, '-i', '-v'])
     assert ret == expected_ret
-    assert io.open(filename).read() == output_src
+    assert path.read() == output_src
 
 
-@pytest.mark.usefixtures('in_tmpdir')
+def test_respects_config_file(tmpdir):
-def test_respects_config_file():
+    with tmpdir.as_cwd():
-    with io.open('setup.cfg', 'w') as setup_cfg:
+        tmpdir.join('setup.cfg').write('[pep8]\nignore=E221')
-        setup_cfg.write('[pep8]\nignore=E221')
+        tmpdir.join('test.py').write('print(1    + 2)\n')
-
-    with io.open('test.py', 'w') as test_py:
-        test_py.write('print(1    + 2)\n')
-
         assert main(['test.py', '-i', '-v']) == 0

tests/check_added_large_files_test.py

@@ -8,18 +8,16 @@ import pytest
 from pre_commit_hooks.check_added_large_files import find_large_added_files
 from pre_commit_hooks.check_added_large_files import main
 from pre_commit_hooks.util import cmd_output
-from testing.util import cwd
-from testing.util import write_file
 
 
 def test_nothing_added(temp_git_dir):
-    with cwd(temp_git_dir):
+    with temp_git_dir.as_cwd():
         assert find_large_added_files(['f.py'], 0) == 0
 
 
 def test_adding_something(temp_git_dir):
-    with cwd(temp_git_dir):
+    with temp_git_dir.as_cwd():
-        write_file('f.py', "print('hello world')")
+        temp_git_dir.join('f.py').write("print('hello world')")
         cmd_output('git', 'add', 'f.py')
 
         # Should fail with max size of 0
@@ -27,8 +25,8 @@ def test_adding_something(temp_git_dir):
 
 
 def test_add_something_giant(temp_git_dir):
-    with cwd(temp_git_dir):
+    with temp_git_dir.as_cwd():
-        write_file('f.py', 'a' * 10000)
+        temp_git_dir.join('f.py').write('a' * 10000)
 
         # Should not fail when not added
         assert find_large_added_files(['f.py'], 0) == 0
@@ -46,8 +44,8 @@ def test_add_something_giant(temp_git_dir):
 
 
 def test_added_file_not_in_pre_commits_list(temp_git_dir):
-    with cwd(temp_git_dir):
+    with temp_git_dir.as_cwd():
-        write_file('f.py', "print('hello world')")
+        temp_git_dir.join('f.py').write("print('hello world')")
         cmd_output('git', 'add', 'f.py')
 
         # Should pass even with a size of 0
@@ -55,10 +53,10 @@ def test_added_file_not_in_pre_commits_list(temp_git_dir):
 
 
 def test_integration(temp_git_dir):
-    with cwd(temp_git_dir):
+    with temp_git_dir.as_cwd():
         assert main(argv=[]) == 0
 
-        write_file('f.py', 'a' * 10000)
+        temp_git_dir.join('f.py').write('a' * 10000)
         cmd_output('git', 'add', 'f.py')
 
         # Should not fail with default
@@ -80,11 +78,11 @@ xfailif_no_gitlfs = pytest.mark.xfail(
 
 @xfailif_no_gitlfs
 def test_allows_gitlfs(temp_git_dir):  # pragma: no cover
-    with cwd(temp_git_dir):
+    with temp_git_dir.as_cwd():
         # Work around https://github.com/github/git-lfs/issues/913
         cmd_output('git', 'commit', '--allow-empty', '-m', 'foo')
         cmd_output('git', 'lfs', 'install')
-        write_file('f.py', 'a' * 10000)
+        temp_git_dir.join('f.py').write('a' * 10000)
         cmd_output('git', 'lfs', 'track', 'f.py')
         cmd_output('git', 'add', '.')
         # Should succeed
@@ -93,11 +91,11 @@ def test_allows_gitlfs(temp_git_dir):  # pragma: no cover
 
 @xfailif_no_gitlfs
 def test_moves_with_gitlfs(temp_git_dir):  # pragma: no cover
-    with cwd(temp_git_dir):
+    with temp_git_dir.as_cwd():
         cmd_output('git', 'lfs', 'install')
         cmd_output('git', 'lfs', 'track', 'a.bin', 'b.bin')
         # First add the file we're going to move
-        write_file('a.bin', 'a' * 10000)
+        temp_git_dir.join('a.bin').write('a' * 10000)
         cmd_output('git', 'add', '.')
         cmd_output('git', 'commit', '-am', 'foo')
         # Now move it and make sure the hook still succeeds

tests/check_case_conflict_test.py

@@ -4,63 +4,61 @@ from __future__ import unicode_literals
 from pre_commit_hooks.check_case_conflict import find_conflicting_filenames
 from pre_commit_hooks.check_case_conflict import main
 from pre_commit_hooks.util import cmd_output
-from testing.util import cwd
-from testing.util import write_file
 
 
 def test_nothing_added(temp_git_dir):
-    with cwd(temp_git_dir):
+    with temp_git_dir.as_cwd():
         assert find_conflicting_filenames(['f.py']) == 0
 
 
 def test_adding_something(temp_git_dir):
-    with cwd(temp_git_dir):
+    with temp_git_dir.as_cwd():
-        write_file('f.py', "print('hello world')")
+        temp_git_dir.join('f.py').write("print('hello world')")
         cmd_output('git', 'add', 'f.py')
 
         assert find_conflicting_filenames(['f.py']) == 0
 
 
 def test_adding_something_with_conflict(temp_git_dir):
-    with cwd(temp_git_dir):
+    with temp_git_dir.as_cwd():
-        write_file('f.py', "print('hello world')")
+        temp_git_dir.join('f.py').write("print('hello world')")
         cmd_output('git', 'add', 'f.py')
-        write_file('F.py', "print('hello world')")
+        temp_git_dir.join('F.py').write("print('hello world')")
         cmd_output('git', 'add', 'F.py')
 
         assert find_conflicting_filenames(['f.py', 'F.py']) == 1
 
 
 def test_added_file_not_in_pre_commits_list(temp_git_dir):
-    with cwd(temp_git_dir):
+    with temp_git_dir.as_cwd():
-        write_file('f.py', "print('hello world')")
+        temp_git_dir.join('f.py').write("print('hello world')")
         cmd_output('git', 'add', 'f.py')
 
         assert find_conflicting_filenames(['g.py']) == 0
 
 
 def test_file_conflicts_with_committed_file(temp_git_dir):
-    with cwd(temp_git_dir):
+    with temp_git_dir.as_cwd():
-        write_file('f.py', "print('hello world')")
+        temp_git_dir.join('f.py').write("print('hello world')")
         cmd_output('git', 'add', 'f.py')
         cmd_output('git', 'commit', '--no-verify', '-m', 'Add f.py')
 
-        write_file('F.py', "print('hello world')")
+        temp_git_dir.join('F.py').write("print('hello world')")
         cmd_output('git', 'add', 'F.py')
 
         assert find_conflicting_filenames(['F.py']) == 1
 
 
 def test_integration(temp_git_dir):
-    with cwd(temp_git_dir):
+    with temp_git_dir.as_cwd():
         assert main(argv=[]) == 0
 
-        write_file('f.py', "print('hello world')")
+        temp_git_dir.join('f.py').write("print('hello world')")
         cmd_output('git', 'add', 'f.py')
 
         assert main(argv=['f.py']) == 0
 
-        write_file('F.py', "print('hello world')")
+        temp_git_dir.join('F.py').write("print('hello world')")
         cmd_output('git', 'add', 'F.py')
 
         assert main(argv=['F.py']) == 1

tests/check_docstring_first_test.py

@@ -1,8 +1,6 @@
 from __future__ import absolute_import
 from __future__ import unicode_literals
 
-import io
-
 import pytest
 
 from pre_commit_hooks.check_docstring_first import check_docstring_first
@@ -59,9 +57,7 @@ def test_unit(capsys, contents, expected, expected_out):
 
 @all_tests
 def test_integration(tmpdir, capsys, contents, expected, expected_out):
-    tmpfilename = tmpdir.join('test.py').strpath
+    f = tmpdir.join('test.py')
-    with io.open(tmpfilename, 'w') as tmpfile:
+    f.write(contents)
-        tmpfile.write(contents)
+    assert main([f.strpath]) == expected
-
+    assert capsys.readouterr()[0] == expected_out.format(filename=f.strpath)
-    assert main([tmpfilename]) == expected
-    assert capsys.readouterr()[0] == expected_out.format(filename=tmpfilename)

tests/check_merge_conflict_test.py

@@ -1,7 +1,6 @@
 from __future__ import absolute_import
 from __future__ import unicode_literals
 
-import io
 import os
 import shutil
 
@@ -9,7 +8,6 @@ import pytest
 
 from pre_commit_hooks.check_merge_conflict import detect_merge_conflict
 from pre_commit_hooks.util import cmd_output
-from testing.util import cwd
 from testing.util import get_resource_path
 from testing.util import write_file
 
@@ -18,28 +16,33 @@ from testing.util import write_file
 
 
 @pytest.yield_fixture
-def f1_is_a_conflict_file(in_tmpdir):
+def f1_is_a_conflict_file(tmpdir):
     # Make a merge conflict
-    cmd_output('git', 'init', 'repo1')
+    repo1 = tmpdir.join('repo1')
-    with cwd('repo1'):
+    repo1_f1 = repo1.join('f1')
-        io.open('f1', 'w').close()
+    repo2 = tmpdir.join('repo2')
-        cmd_output('git', 'add', 'f1')
+    repo2_f1 = repo2.join('f1')
-        cmd_output('git', 'commit', '-m' 'commit1')
 
-    cmd_output('git', 'clone', 'repo1', 'repo2')
+    cmd_output('git', 'init', repo1.strpath)
+    with repo1.as_cwd():
+        repo1_f1.ensure()
+        cmd_output('git', 'add', repo1_f1.strpath)
+        cmd_output('git', 'commit', '-m', 'commit1')
+
+    cmd_output('git', 'clone', repo1.strpath, repo2.strpath)
 
     # Commit in master
-    with cwd('repo1'):
+    with repo1.as_cwd():
-        write_file('f1', 'parent\n')
+        repo1_f1.write('parent\n')
         cmd_output('git', 'commit', '-am', 'master commit2')
 
     # Commit in clone and pull
-    with cwd('repo2'):
+    with repo2.as_cwd():
-        write_file('f1', 'child\n')
+        repo2_f1.write('child\n')
         cmd_output('git', 'commit', '-am', 'clone commit2')
         cmd_output('git', 'pull', retcode=None)
         # We should end up in a merge conflict!
-        f1 = io.open('f1').read()
+        f1 = repo2_f1.read()
         assert f1.startswith(
             '<<<<<<< HEAD\n'
             'child\n'
@@ -60,30 +63,35 @@ def f1_is_a_conflict_file(in_tmpdir):
 
 
 @pytest.yield_fixture
-def repository_is_pending_merge(in_tmpdir):
+def repository_is_pending_merge(tmpdir):
     # Make a (non-conflicting) merge
-    cmd_output('git', 'init', 'repo1')
+    repo1 = tmpdir.join('repo1')
-    with cwd('repo1'):
+    repo1_f1 = repo1.join('f1')
-        io.open('f1', 'w').close()
+    repo2 = tmpdir.join('repo2')
-        cmd_output('git', 'add', 'f1')
+    repo2_f1 = repo2.join('f1')
+    repo2_f2 = repo2.join('f2')
+    cmd_output('git', 'init', repo1.strpath)
+    with repo1.as_cwd():
+        repo1_f1.ensure()
+        cmd_output('git', 'add', repo1_f1.strpath)
         cmd_output('git', 'commit', '-m' 'commit1')
 
-    cmd_output('git', 'clone', 'repo1', 'repo2')
+    cmd_output('git', 'clone', repo1.strpath, repo2.strpath)
 
     # Commit in master
-    with cwd('repo1'):
+    with repo1.as_cwd():
-        write_file('f1', 'parent\n')
+        repo1_f1.write('parent\n')
         cmd_output('git', 'commit', '-am', 'master commit2')
 
     # Commit in clone and pull without committing
-    with cwd('repo2'):
+    with repo2.as_cwd():
-        write_file('f2', 'child\n')
+        repo2_f2.write('child\n')
-        cmd_output('git', 'add', 'f2')
+        cmd_output('git', 'add', repo2_f2.strpath)
         cmd_output('git', 'commit', '-m', 'clone commit2')
         cmd_output('git', 'pull', '--no-commit')
         # We should end up in a pending merge
-        assert io.open('f1').read().startswith('parent\n')
+        assert repo2_f1.read() == 'parent\n'
-        assert io.open('f2').read().startswith('child\n')
+        assert repo2_f2.read() == 'child\n'
         assert os.path.exists(os.path.join('.git', 'MERGE_HEAD'))
         yield
 
@@ -117,8 +125,6 @@ def test_ignores_binary_files():
     assert detect_merge_conflict(['f1']) == 0
 
 
-@pytest.mark.usefixtures('in_tmpdir')
+def test_does_not_care_when_not_in_a_merge(tmpdir):
-def test_does_not_care_when_not_in_a_merge():
+    tmpdir.join('README.md').write('problem\n=======\n')
-    with io.open('README.md', 'w') as readme_file:
-        readme_file.write('problem\n=======\n')
     assert detect_merge_conflict(['README.md']) == 0

tests/conftest.py

@@ -5,17 +5,10 @@ from __future__ import unicode_literals
 import pytest
 
 from pre_commit_hooks.util import cmd_output
-from testing.util import cwd
-
-
-@pytest.yield_fixture
-def in_tmpdir(tmpdir):
-    with cwd(tmpdir.strpath):
-        yield tmpdir
 
 
 @pytest.yield_fixture
 def temp_git_dir(tmpdir):
-    git_dir = tmpdir.join('gits').strpath
+    git_dir = tmpdir.join('gits')
-    cmd_output('git', 'init', git_dir)
+    cmd_output('git', 'init', git_dir.strpath)
     yield git_dir

tests/detect_aws_credentials_test.py

@@ -16,9 +16,10 @@ TESTS = (
 @pytest.mark.parametrize(('filename', 'expected_retval'), TESTS)
 def test_detect_aws_credentials(filename, expected_retval):
     # with a valid credentials file
-    ret = main(
+    ret = main((
-        [get_resource_path(filename), "--credentials-file=testing/resources/sample_aws_credentials"]
+        get_resource_path(filename),
-    )
+        "--credentials-file=testing/resources/sample_aws_credentials",
+    ))
     assert ret == expected_retval
 
 

tests/detect_private_key_test.py

@@ -1,5 +1,3 @@
-import os.path
-
 import pytest
 
 from pre_commit_hooks.detect_private_key import detect_private_key
@@ -18,9 +16,6 @@ TESTS = (
 
 @pytest.mark.parametrize(('input_s', 'expected_retval'), TESTS)
 def test_detect_private_key(input_s, expected_retval, tmpdir):
-    path = os.path.join(tmpdir.strpath, 'file.txt')
+    path = tmpdir.join('file.txt')
-
+    path.write_binary(input_s)
-    with open(path, 'wb') as file_obj:
+    assert detect_private_key([path.strpath]) == expected_retval
-        file_obj.write(input_s)
-
-    assert detect_private_key([path]) == expected_retval

tests/end_of_file_fixer_test.py

@@ -1,5 +1,4 @@
 import io
-import os.path
 
 import pytest
 
@@ -21,8 +20,7 @@ TESTS = (
 
 @pytest.mark.parametrize(('input_s', 'expected_retval', 'output'), TESTS)
 def test_fix_file(input_s, expected_retval, output):
-    file_obj = io.BytesIO()
+    file_obj = io.BytesIO(input_s)
-    file_obj.write(input_s)
     ret = fix_file(file_obj)
     assert file_obj.getvalue() == output
     assert ret == expected_retval
@@ -30,13 +28,11 @@ def test_fix_file(input_s, expected_retval, output):
 
 @pytest.mark.parametrize(('input_s', 'expected_retval', 'output'), TESTS)
 def test_integration(input_s, expected_retval, output, tmpdir):
-    file_path = os.path.join(tmpdir.strpath, 'file.txt')
+    path = tmpdir.join('file.txt')
+    path.write_binary(input_s)
 
-    with open(file_path, 'wb') as file_obj:
+    ret = end_of_file_fixer([path.strpath])
-        file_obj.write(input_s)
+    file_output = path.read_binary()
-
-    ret = end_of_file_fixer([file_path])
-    file_output = open(file_path, 'rb').read()
 
     assert file_output == output
     assert ret == expected_retval

tests/pretty_format_json_test.py

@@ -1,4 +1,4 @@
-import io
+import shutil
 
 import pytest
 
@@ -28,8 +28,10 @@ def test_unsorted_pretty_format_json(filename, expected_retval):
 
 def test_autofix_pretty_format_json(tmpdir):
     srcfile = tmpdir.join('to_be_json_formatted.json')
-    with io.open(get_resource_path('not_pretty_formatted_json.json')) as f:
+    shutil.copyfile(
-        srcfile.write_text(f.read(), 'UTF-8')
+        get_resource_path('not_pretty_formatted_json.json'),
+        srcfile.strpath,
+    )
 
     # now launch the autofix on that file
     ret = pretty_format_json(['--autofix', srcfile.strpath])

tests/requirements_txt_fixer_test.py

@@ -1,5 +1,3 @@
-import os.path
-
 import pytest
 
 from pre_commit_hooks.requirements_txt_fixer import fix_requirements_txt
@@ -22,13 +20,11 @@ TESTS = (
 
 @pytest.mark.parametrize(('input_s', 'expected_retval', 'output'), TESTS)
 def test_integration(input_s, expected_retval, output, tmpdir):
-    path = os.path.join(tmpdir.strpath, 'file.txt')
+    path = tmpdir.join('file.txt')
+    path.write_binary(input_s)
 
-    with open(path, 'wb') as file_obj:
+    assert fix_requirements_txt([path.strpath]) == expected_retval
-        file_obj.write(input_s)
+    assert path.read_binary() == output
-
-    assert fix_requirements_txt([path]) == expected_retval
-    assert open(path, 'rb').read() == output
 
 
 def test_requirement_object():

tests/string_fixer_test.py

@@ -40,11 +40,8 @@ TESTS = (
 
 @pytest.mark.parametrize(('input_s', 'output', 'expected_retval'), TESTS)
 def test_rewrite(input_s, output, expected_retval, tmpdir):
-    tmpfile = tmpdir.join('file.txt')
+    path = tmpdir.join('file.txt')
-
+    path.write(input_s)
-    with open(tmpfile.strpath, 'w') as f:
+    retval = main([path.strpath])
-        f.write(input_s)
+    assert path.read() == output
-
-    retval = main([tmpfile.strpath])
-    assert tmpfile.read() == output
     assert retval == expected_retval

tests/trailing_whitespace_fixer_test.py

@@ -1,31 +1,23 @@
 from __future__ import absolute_import
 from __future__ import unicode_literals
 
-import sys
-
 import pytest
 
 from pre_commit_hooks.trailing_whitespace_fixer import fix_trailing_whitespace
-from testing.util import cwd
 
 
-def test_fixes_trailing_whitespace(tmpdir):
+@pytest.mark.parametrize(
-    with cwd(tmpdir.strpath):
+    ('input_s', 'expected'),
-        for filename, contents in (
+    (
-                ('foo.py', 'foo \nbar \n'),
+        ('foo \nbar \n', 'foo\nbar\n'),
-                ('bar.py', 'bar\t\nbaz\t\n'),
+        ('bar\t\nbaz\t\n', 'bar\nbaz\n'),
-        ):
+    ),
-            with open(filename, 'w') as file_obj:
+)
-                file_obj.write(contents)  # pragma: no branch (26 coverage bug)
+def test_fixes_trailing_whitespace(input_s, expected, tmpdir):
-
+    path = tmpdir.join('file.txt')
-        ret = fix_trailing_whitespace(['foo.py', 'bar.py'])
+    path.write(input_s)
-        assert ret == 1
+    assert fix_trailing_whitespace((path.strpath,)) == 1
-
+    assert path.read() == expected
-        for filename, after_contents in (
-                ('foo.py', 'foo\nbar\n'),
-                ('bar.py', 'bar\nbaz\n'),
-        ):
-            assert open(filename).read() == after_contents
 
 
 # filename, expected input, expected output
@@ -39,13 +31,11 @@ MD_TESTS_1 = (
 
 @pytest.mark.parametrize(('filename', 'input_s', 'output'), MD_TESTS_1)
 def test_fixes_trailing_markdown_whitespace(filename, input_s, output, tmpdir):
-    with cwd(tmpdir.strpath):
+    path = tmpdir.join(filename)
-        with open(filename, 'w') as file_obj:
+    path.write(input_s)
-            file_obj.write(input_s)  # pragma: no branch (26 coverage bug)
+    ret = fix_trailing_whitespace([path.strpath])
-
-        ret = fix_trailing_whitespace([filename])
     assert ret == 1
-        assert open(filename).read() == output
+    assert path.read() == output
 
 
 # filename, expected input, expected output
@@ -60,14 +50,13 @@ MD_TESTS_2 = (
 
 @pytest.mark.parametrize(('filename', 'input_s', 'output'), MD_TESTS_2)
 def test_markdown_linebreak_ext_opt(filename, input_s, output, tmpdir):
-    with cwd(tmpdir.strpath):
+    path = tmpdir.join(filename)
-        with open(filename, 'w') as file_obj:
+    path.write(input_s)
-            file_obj.write(input_s)  # pragma: no branch (26 coverage bug)
+    ret = fix_trailing_whitespace((
-
+        '--markdown-linebreak-ext=TxT', path.strpath
-        ret = fix_trailing_whitespace(['--markdown-linebreak-ext=TxT',
+    ))
-                                       filename])
     assert ret == 1
-        assert open(filename).read() == output
+    assert path.read() == output
 
 
 # filename, expected input, expected output
@@ -79,25 +68,21 @@ MD_TESTS_3 = (
 
 @pytest.mark.parametrize(('filename', 'input_s', 'output'), MD_TESTS_3)
 def test_markdown_linebreak_ext_opt_all(filename, input_s, output, tmpdir):
-    with cwd(tmpdir.strpath):
+    path = tmpdir.join(filename)
-        with open(filename, 'w') as file_obj:
+    path.write(input_s)
-            file_obj.write(input_s)  # pragma: no branch (26 coverage bug)
-
     # need to make sure filename is not treated as argument to option
-        ret = fix_trailing_whitespace(['--markdown-linebreak-ext=*',
+    ret = fix_trailing_whitespace([
-                                       filename])
+        '--markdown-linebreak-ext=*', path.strpath,
+    ])
     assert ret == 1
-        assert open(filename).read() == output
+    assert path.read() == output
 
 
 @pytest.mark.parametrize(('arg'), ('--', 'a.b', 'a/b'))
 def test_markdown_linebreak_ext_badopt(arg):
-    try:
+    with pytest.raises(SystemExit) as excinfo:
-        ret = fix_trailing_whitespace(['--markdown-linebreak-ext', arg])
+        fix_trailing_whitespace(['--markdown-linebreak-ext', arg])
-    except SystemExit:
+    assert excinfo.value.code == 2
-        ret = sys.exc_info()[1].code
-    finally:
-        assert ret == 2
 
 
 # filename, expected input, expected output
@@ -109,13 +94,11 @@ MD_TESTS_4 = (
 
 @pytest.mark.parametrize(('filename', 'input_s', 'output'), MD_TESTS_4)
 def test_no_markdown_linebreak_ext_opt(filename, input_s, output, tmpdir):
-    with cwd(tmpdir.strpath):
+    path = tmpdir.join(filename)
-        with open(filename, 'w') as file_obj:
+    path.write(input_s)
-            file_obj.write(input_s)  # pragma: no branch (26 coverage bug)
+    ret = fix_trailing_whitespace(['--no-markdown-linebreak-ext', path.strpath])
-
-        ret = fix_trailing_whitespace(['--no-markdown-linebreak-ext', filename])
     assert ret == 1
-        assert open(filename).read() == output
+    assert path.read() == output
 
 
 def test_returns_zero_for_no_changes():