Add a checker for executables without shebangs
diff --git a/tests/check_executables_have_shebangs_test.py b/tests/check_executables_have_shebangs_test.py
new file mode 100644
index 0000000..0e28986
--- /dev/null
+++ b/tests/check_executables_have_shebangs_test.py
@@ -0,0 +1,35 @@
+# -*- coding: utf-8 -*-
+from __future__ import absolute_import
+from __future__ import unicode_literals
+
+import pytest
+
+from pre_commit_hooks.check_executables_have_shebangs import main
+
+
+@pytest.mark.parametrize('content', (
+ b'#!/bin/bash\nhello world\n',
+ b'#!/usr/bin/env python3.6',
+ b'#!python',
+ '#!☃'.encode('UTF-8'),
+))
+def test_has_shebang(content, tmpdir):
+ path = tmpdir.join('path')
+ path.write(content, 'wb')
+ assert main((path.strpath,)) == 0
+
+
+@pytest.mark.parametrize('content', (
+ b'',
+ b' #!python\n',
+ b'\n#!python\n',
+ b'python\n',
+ '☃'.encode('UTF-8'),
+
+))
+def test_bad_shebang(content, tmpdir, capsys):
+ path = tmpdir.join('path')
+ path.write(content, 'wb')
+ assert main((path.strpath,)) == 1
+ _, stderr = capsys.readouterr()
+ assert stderr.startswith('{}: marked executable but'.format(path.strpath))
