diff options
| -rw-r--r-- | Lib/argparse.py | 4 | ||||
| -rw-r--r-- | Lib/test/test_argparse.py | 18 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2019-06-04-14-44-41.bpo-37150.TTzHxj.rst | 1 |
3 files changed, 23 insertions, 0 deletions
diff --git a/Lib/argparse.py b/Lib/argparse.py index ef888f063b..9a67b41ae0 100644 --- a/Lib/argparse.py +++ b/Lib/argparse.py @@ -1361,6 +1361,10 @@ class _ActionsContainer(object): if not callable(type_func): raise ValueError('%r is not callable' % (type_func,)) + if type_func is FileType: + raise ValueError('%r is a FileType class object, instance of it' + ' must be passed' % (type_func,)) + # raise an error if the metavar does not match the type if hasattr(self, "_get_formatter"): try: diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py index 9d68f40571..bcf2cc9b26 100644 --- a/Lib/test/test_argparse.py +++ b/Lib/test/test_argparse.py @@ -1619,6 +1619,24 @@ class TestFileTypeOpenArgs(TestCase): m.assert_called_with('foo', *args) +class TestFileTypeMissingInitialization(TestCase): + """ + Test that add_argument throws an error if FileType class + object was passed instead of instance of FileType + """ + + def test(self): + parser = argparse.ArgumentParser() + with self.assertRaises(ValueError) as cm: + parser.add_argument('-x', type=argparse.FileType) + + self.assertEqual( + '%r is a FileType class object, instance of it must be passed' + % (argparse.FileType,), + str(cm.exception) + ) + + class TestTypeCallable(ParserTestCase): """Test some callables as option/argument types""" diff --git a/Misc/NEWS.d/next/Library/2019-06-04-14-44-41.bpo-37150.TTzHxj.rst b/Misc/NEWS.d/next/Library/2019-06-04-14-44-41.bpo-37150.TTzHxj.rst new file mode 100644 index 0000000000..c5be46e1e5 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2019-06-04-14-44-41.bpo-37150.TTzHxj.rst @@ -0,0 +1 @@ +`argparse._ActionsContainer.add_argument` now throws error, if someone accidentally pass FileType class object instead of instance of FileType as `type` argument
\ No newline at end of file |