Keep compatibility in default value of value_converter (#96)

Author: epsy

clize/converters.py

@@ -76,8 +76,12 @@ def _silence_convert_default_warning():
         yield
 
 
+def _conversion_filter(arg):
+    return isinstance(arg, str)
+
+
 with _silence_convert_default_warning():
-    @parser.value_converter(name='FILE', convert_default=True)
+    @parser.value_converter(name='FILE', convert_default=True, convert_default_filter=_conversion_filter)
     @autokwoargs(exceptions=['arg'])
     def file(arg=util.UNSET, stdio='-', keep_stdio_open=False, **kwargs):
         """Takes a file argument and provides a Python object that opens a file
@@ -114,7 +118,7 @@ def main(inf: (file(), Parameter.cli_default("-"))):
             return parser.value_converter(
                 partial(_FileOpener, kwargs=kwargs,
                         stdio=stdio, keep_stdio_open=keep_stdio_open),
-                name='FILE', convert_default=True)
+                name='FILE', convert_default=True, convert_default_filter=_conversion_filter)
 
 
 def _convert_ioerror(arg, exc):

clize/parser.py

@@ -232,7 +232,7 @@ def __init__(self, **kwargs):
             display_name='<internal>', **kwargs)
 
 
-def value_converter(func=None, *, name=None, convert_default=None, convert_default_filter=lambda s: isinstance(s, str)):
+def value_converter(func=None, *, name=None, convert_default=None, convert_default_filter=lambda s: True):
     """Callables decorated with this can be used as a value converter.
 
     :param str name: Use this name to designate the parameter value type.