Omit extra space in kwarg unpacking if it's an argument

Fixes #46

README.md

@@ -298,6 +298,9 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md).
 * don't omit whitespace if the previous factor leaf wasn't a math
   operator (#55)
 
+* omit extra space in kwarg unpacking if it's the first argument (#46)
+
+
 ### 18.3a3
 
 * don't remove single empty lines outside of bracketed expressions

black.py

@@ -867,21 +867,22 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
 
         if prevp.type == token.EQUAL:
             if prevp.parent and prevp.parent.type in {
-                syms.typedargslist,
-                syms.varargslist,
-                syms.parameters,
                 syms.arglist,
                 syms.argument,
+                syms.parameters,
+                syms.typedargslist,
+                syms.varargslist,
             }:
                 return NO
 
         elif prevp.type == token.DOUBLESTAR:
             if prevp.parent and prevp.parent.type in {
+                syms.arglist,
+                syms.argument,
+                syms.dictsetmaker,
+                syms.parameters,
                 syms.typedargslist,
                 syms.varargslist,
-                syms.parameters,
-                syms.arglist,
-                syms.dictsetmaker,
             }:
                 return NO
 

tests/expression.py

@@ -75,6 +75,7 @@
 call(arg, another, kwarg='hey', **kwargs)
 call(this_is_a_very_long_variable_which_will_force_a_delimiter_split, arg, another, kwarg='hey', **kwargs)  # note: no trailing comma pre-3.6
 call(*gidgets[:2])
+call(**self.screen_kwargs)
 lukasz.langa.pl
 call.me(maybe)
 1 .real
@@ -237,6 +238,7 @@ async def f():
     **kwargs
 )  # note: no trailing comma pre-3.6
 call(*gidgets[:2])
+call(**self.screen_kwargs)
 lukasz.langa.pl
 call.me(maybe)
 1 .real