Merge pull request pytest-dev#138 from ambv/star-expr

Parse complex expressions in parameters after * and **

Author: zsol

README.md

@@ -496,6 +496,9 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md).
 * generalized star expression handling, including double stars; this
   fixes multiplication making expressions "unsafe" for trailing commas (#132)
 
+* fix parsing of complex expressions after star and double stars in 
+  function parameters (#2)
+
 ### 18.4a2
 
 * fixed parsing of unaligned standalone comments (#99, #112)

black.py

@@ -1364,7 +1364,7 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
             if not prevp or prevp.type == token.LPAR:
                 return NO
 
-        elif prev.type == token.EQUAL or prev.type == token.DOUBLESTAR:
+        elif prev.type in {token.EQUAL} | STARS:
             return NO
 
     elif p.type == syms.decorator:
@@ -2165,7 +2165,7 @@ def is_python36(node: Node) -> bool:
             and n.children[-1].type == token.COMMA
         ):
             for ch in n.children:
-                if ch.type == token.STAR or ch.type == token.DOUBLESTAR:
+                if ch.type in STARS:
                     return True
 
     return False

blib2to3/Grammar.txt

@@ -138,8 +138,8 @@ arglist: argument (',' argument)* [',']
 # that precede iterable unpackings are blocked; etc.
 argument: ( test [comp_for] |
             test '=' test |
-	    '**' expr |
-	    star_expr )
+	    '**' test |
+            '*' test )
 
 comp_iter: comp_for | comp_if
 comp_for: [ASYNC] 'for' exprlist 'in' or_test [comp_iter]

blib2to3/Grammar3.6.5.final.0.pickle

@@ -117,7 +117,7 @@
  ]
  slice[0]
  slice[0:1]
-@@ -121,85 +135,119 @@
+@@ -121,88 +135,122 @@
  numpy[-(c + 1):, d]
  numpy[:, l[-2]]
  numpy[:, ::-1]
@@ -184,6 +184,12 @@
 
  async def f():
      await some.complicated[0].call(with_args=(True or (1 is not 1)))
+-print(* [] or [1])
++
++
++print(*[] or [1])
+ print(**{1: 3} if False else {x: x for x in range(3)})
+-print(* lambda x: x)
 -for x, in (1,), (2,), (3,): ...
 -for y in (): ...
 -for z in (i for i in (1, 2, 3)): ...
@@ -226,8 +232,7 @@
 -    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 -):
 -    return True
-+
-+
++print(*lambda x: x)
 +for (x,) in (1,), (2,), (3,):
 +    ...
 +for y in ():

tests/expression.diff

@@ -158,6 +158,9 @@ def gen():
 
 async def f():
     await some.complicated[0].call(with_args=(True or (1 is not 1)))
+print(* [] or [1])
+print(**{1: 3} if False else {x: x for x in range(3)})
+print(* lambda x: x)
 for x, in (1,), (2,), (3,): ...
 for y in (): ...
 for z in (i for i in (1, 2, 3)): ...
@@ -402,6 +405,9 @@ async def f():
     await some.complicated[0].call(with_args=(True or (1 is not 1)))
 
 
+print(*[] or [1])
+print(**{1: 3} if False else {x: x for x in range(3)})
+print(*lambda x: x)
 for (x,) in (1,), (2,), (3,):
     ...
 for y in ():