Adds a test for default file init command.

tests/test_commands.py

@@ -112,6 +112,17 @@ def test_install_requirements_for_file(runner):
     install_mock.assert_called_once_with(os.path.join(dirname, 'requirements.txt'))
 
 
+@all_runners
+def test_init_file(runner, tmpdir):
+    target = tmpdir.join('foo.py')
+    runner('init', str(target))
+    assert os.path.exists(target)
+
+    out, err = runner('run', str(target))
+    assert out.replace('\n', ' ').strip() == 'Hello World'
+    assert not err
+
+
 @all_runners
 def test_version(runner):
     out, err = runner('version')