bpo-37150: Throw ValueError if FileType class object was passed in add_argument (GH-13805)
There is a possibility that someone (like me) accidentally will omit parentheses with `FileType` arguments after `FileType`, and parser will contain wrong file until someone will try to use it.
Example:
```python
parser = argparse.ArgumentParser()
parser.add_argument('-x', type=argparse.FileType)
```
https://bugs.python.org/issue37150
(cherry picked from commit 03d5831a2d62c68654ec223168e574cd546efbf6)
Co-authored-by: zygocephalus <grrrr@protonmail.com>diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
index 9d68f40..bcf2cc9 100644
--- a/Lib/test/test_argparse.py
+++ b/Lib/test/test_argparse.py
@@ -1619,6 +1619,24 @@
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"""