Add PrefixedCommandRunner

tests/prefixed_command_runner_test.py

@@ -0,0 +1,78 @@
+
+import mock
+import pytest
+import subprocess
+
+from pre_commit.prefixed_command_runner import _replace_cmd
+from pre_commit.prefixed_command_runner import PrefixedCommandRunner
+
+
+@pytest.fixture
+def popen_mock():
+    popen = mock.Mock()
+    popen.return_value.communicate.return_value = (mock.Mock(), mock.Mock())
+    return popen
+
+
+@pytest.mark.parametrize(('input', 'kwargs', 'expected_output'), (
+    ([], {}, []),
+    (['foo'], {}, ['foo']),
+    ([], {'foo': 'bar'}, []),
+    (['{foo}/baz'], {'foo': 'bar'}, ['bar/baz']),
+    (['foo'], {'foo': 'bar'}, ['foo']),
+    (['foo', '{bar}'], {'bar': 'baz'}, ['foo', 'baz']),
+))
+def test_replace_cmd(input, kwargs, expected_output):
+    ret = _replace_cmd(input, **kwargs)
+    assert ret == expected_output
+
+
+@pytest.mark.parametrize(('input', 'expected_prefix'), (
+    ('.', './'),
+    ('foo', 'foo/'),
+    ('bar/', 'bar/'),
+    ('foo/bar', 'foo/bar/'),
+    ('foo/bar/', 'foo/bar/'),
+))
+def test_init_normalizes_path_endings(input, expected_prefix):
+    instance = PrefixedCommandRunner(input)
+    assert instance.prefix_dir == expected_prefix
+
+
+def test_run_substitutes_prefix(popen_mock):
+    instance = PrefixedCommandRunner('prefix', popen=popen_mock)
+    ret = instance.run(['{prefix}bar', 'baz'])
+    popen_mock.assert_called_once_with(
+        ['prefix/bar', 'baz'],
+        stdin=subprocess.PIPE,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+    )
+    assert ret == (
+        popen_mock.return_value.returncode,
+        popen_mock.return_value.communicate.return_value[0],
+        popen_mock.return_value.communicate.return_value[1],
+    )
+
+
+@pytest.mark.parametrize(('first_prefix', 'postfix', 'expected_output'), (
+    ('foo', '', 'foo/'),
+    ('foo', 'bar', 'foo/bar/'),
+    ('./', 'bar', './bar/'),
+))
+def test_from_command_runner(first_prefix, postfix, expected_output):
+    first = PrefixedCommandRunner(first_prefix)
+    second = PrefixedCommandRunner.from_command_runner(first, postfix)
+    assert second.prefix_dir == expected_output
+
+
+def test_from_command_runner_preserves_popen(popen_mock):
+    first = PrefixedCommandRunner('foo', popen=popen_mock)
+    second = PrefixedCommandRunner.from_command_runner(first, 'bar')
+    second.run(['foo/bar/baz'])
+    popen_mock.assert_called_once_with(
+        ['foo/bar/baz'],
+        stdin=subprocess.PIPE,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+    )