Many changes from the new toolchain

Author: rec

safer/__init__.py

@@ -147,6 +147,7 @@
         # Either the whole file is written, or nothing
 
 """
+
 from __future__ import annotations
 
 import contextlib
@@ -253,6 +254,7 @@ def writer(
                 raise NotImplementedError(BUG_MESSAGE)
 
             def write(v):
+                assert isinstance(stream, t.ContextManager), (stream, type(stream))
                 with stream:
                     stream.write(v)
 
@@ -399,7 +401,7 @@ def open(
     parent = os.path.dirname(os.path.abspath(name))
     if not os.path.exists(parent):
         if not make_parents:
-            raise IOError('Directory does not exist')
+            raise OSError('Directory does not exist')
         os.makedirs(parent)
 
     def simple_open():
@@ -552,7 +554,7 @@ def printer(
       Same as for `safer.open()`
     """
     if 'r' in mode and '+' not in mode:
-        raise IOError('File not open for writing')
+        raise OSError('File not open for writing')
 
     if 'b' in mode:
         raise ValueError('Cannot print to a file open in binary mode')
@@ -598,7 +600,7 @@ def wrapped(*args, **kwargs):
 
 
 # Wrap an existing IO class so that it calls safer at the end
-@functools.lru_cache()
+@functools.lru_cache
 def _wrap_class(stream_cls):
     @functools.wraps(stream_cls.__exit__)
     def exit(self, *args):

test/test_open.py

@@ -153,7 +153,7 @@ def test_file_perms(self, safer_open):
         elif os.name == 'nt':
             new_mode = mode
         else:
-            assert False, f'Do not understand os.name = {os.name}'
+            raise ValueError(f'Do not understand os.name = {os.name}')
 
         os.chmod(FILENAME, new_mode)
         with safer_open(FILENAME, 'w') as fp: