Fixed partial so that when no argument is provided, it is equivalen…

…t to `wraps(f)(f)`. That is, the `__wrapped__` attribute is set. Fixed #73

src/makefun/main.py

@@ -1107,7 +1107,10 @@ def partial(f,                 # type: Callable
 
     # (1) remove/change all preset arguments from the signature
     orig_sig = signature(f)
-    new_sig = gen_partial_sig(orig_sig, preset_pos_args, preset_kwargs, f)
+    if preset_pos_args or preset_kwargs:
+        new_sig = gen_partial_sig(orig_sig, preset_pos_args, preset_kwargs, f)
+    else:
+        new_sig = None
 
     if _is_generator_func(f):
         if sys.version_info >= (3, 3):
@@ -1125,7 +1128,8 @@ def partial_f(*args, **kwargs):
 
     # update the doc.
     # Note that partial_f is generated above with a proper __name__ and __doc__ identical to the wrapped ones
-    partial_f.__doc__ = gen_partial_doc(partial_f.__name__, partial_f.__doc__, orig_sig, new_sig, preset_pos_args)
+    if new_sig is not None:
+        partial_f.__doc__ = gen_partial_doc(partial_f.__name__, partial_f.__doc__, orig_sig, new_sig, preset_pos_args)
 
     return partial_f
 

tests/test_partial_and_macros.py

@@ -172,3 +172,19 @@ def f(a, b, c, **d):
             makefun.partial(f, b=0)
 
         # assert str(signature(fp_ref)) == str(signature(fp))
+
+
+def test_simple_partial_copy():
+    """Test that when not providing any argument to partial, it is equivalent to wraps with new sig = None"""
+    def f1(a):
+        return a + 1
+
+    f2 = makefun.partial(f1)
+
+    # make sure that this is the same as wraps
+    assert f2.__wrapped__ == f1
+
+    f3 = makefun.wraps(f1)(f1)
+    assert f3.__wrapped__ == f1
+
+    assert f2(1) == f3(1) == 2