BREAKING: bytes annotation now re-encodes the corresponding parameter back to bytes (#89)

This also adds tests for using pathlib.Path types, and removes old compatibility for pre-pathlib Python releases (<=3.3)

Author: epsy

clize/parser.py

@@ -8,6 +8,7 @@
 
 import itertools
 import inspect
+import os
 import typing
 from functools import partial, wraps
 import pathlib
@@ -265,26 +266,30 @@ def identity(x=None):
     return x
 
 
+@value_converter(name='BYTES')
+def convert_back_to_bytes(arg):
+    return os.fsencode(arg)
+
+
 @value_converter(name='BOOL')
 def is_true(arg):
     return arg.lower() not in ('', '0', 'n', 'no', 'f', 'false')
 
 
+@value_converter(name='PATH')
+def concrete_path_converter(arg):
+    return pathlib.Path(arg)
+
+
 _implicit_converters = {
     int: int,
     float: float,
     bool: is_true,
     str: identity,
-    bytes: identity,
+    bytes: convert_back_to_bytes,
+    pathlib.PurePath: concrete_path_converter
 }
 
-if pathlib:
-    @value_converter(name='PATH')
-    def path_converter(arg):
-        return pathlib.Path(arg)
-
-    _implicit_converters[pathlib.PurePath] = path_converter
-
 
 def get_value_converter(annotation):
     try:

clize/tests/test_parser.py

@@ -3,6 +3,7 @@
 # COPYING for details.
 import functools
 import inspect
+import os
 import pathlib
 import typing
 import warnings
@@ -439,6 +440,15 @@ def _test(self, sig, str_rep, args, posargs, kwargs, *, make_signature):
 
     ignored = s('one:P.I'), '', (), [], {}
 
+    bytes = s("a: bytes"), 'a', ('\u1234',), [os.fsencode('\u1234')], {}
+    bytes_named = s("*, a: bytes"), '-a BYTES', ('-a\u1234',), [], {'a': os.fsencode('\u1234')}
+
+    path = s("*, a: ann", ann=pathlib.Path), '-a PATH', ('-a./abc/def',), [], {'a': pathlib.Path('./abc/def')}
+    path_default = (
+        s("*, a = default", default=pathlib.Path('./abc',)),
+        '[-a PATH]', ('-a./def',), [], {'a': pathlib.Path('./def')},
+    )
+
     def test_converter_ignore(self):
         @parser.parameter_converter
         def conv(param, annotations, *, type_annotation):