fix unstable formatting when unpacking big tuples (#514)

* fix unstable formatting when unpacking big tuples

* add changelog entry

diff --git a/README.md b/README.md
index 6aad8bc61c5fb50d26e82d53fcb236cc0ec2737e..6d350d04f8a94c92d9deadab2c7d799cd4ee9b6f 100644 (file)
--- a/README.md
+++ b/README.md
@@ -874,6 +874,8 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md).
 
 * *Black* no longer breaks ``async for`` statements up to separate lines (#372)
 
+* fixed unstable formatting when unpacking big tuples (#267)
+
 
 ### 18.6b4
 

diff --git a/black.py b/black.py
index 6f7496ede2345e597c3b3145fc268d65c8f7b416..8d53194680309ce664af0e0a77105c31c2343824 100644 (file)
--- a/black.py
+++ b/black.py
@@ -2976,7 +2976,6 @@ def generate_trailers_to_omit(line: Line, line_length: int) -> Iterator[Set[Leaf
     length = 4 * line.depth
     opening_bracket = None
     closing_bracket = None
-    optional_brackets: Set[LeafID] = set()
     inner_brackets: Set[LeafID] = set()
     for index, leaf, leaf_length in enumerate_with_length(line, reversed=True):
         length += leaf_length
@@ -2987,17 +2986,12 @@ def generate_trailers_to_omit(line: Line, line_length: int) -> Iterator[Set[Leaf
         if leaf.type == STANDALONE_COMMENT or has_inline_comment:
             break
 
-        optional_brackets.discard(id(leaf))
         if opening_bracket:
             if leaf is opening_bracket:
                 opening_bracket = None
             elif leaf.type in CLOSING_BRACKETS:
                 inner_brackets.add(id(leaf))
         elif leaf.type in CLOSING_BRACKETS:
-            if not leaf.value:
-                optional_brackets.add(id(opening_bracket))
-                continue
-
             if index > 0 and line.leaves[index - 1].type in OPENING_BRACKETS:
                 # Empty brackets would fail a split so treat them as "inner"
                 # brackets (e.g. only add them to the `omit` set if another
@@ -3005,13 +2999,15 @@ def generate_trailers_to_omit(line: Line, line_length: int) -> Iterator[Set[Leaf
                 inner_brackets.add(id(leaf))
                 continue
 
-            opening_bracket = leaf.opening_bracket
             if closing_bracket:
                 omit.add(id(closing_bracket))
                 omit.update(inner_brackets)
                 inner_brackets.clear()
                 yield omit
-            closing_bracket = leaf
+
+            if leaf.value:
+                opening_bracket = leaf.opening_bracket
+                closing_bracket = leaf
 
 
 def get_future_imports(node: Node) -> Set[str]:

diff --git a/tests/data/expression.diff b/tests/data/expression.diff
index 8b73f321582783cf27520074e4c29a32592b9067..b26d9315d803881a734b6d7928a70a47f6e22c89 100644 (file)
--- a/tests/data/expression.diff
+++ b/tests/data/expression.diff
@@ -147,7 +147,7 @@
  slice[0:1:2]
  slice[:]
  slice[:-1]
-@@ -133,109 +156,161 @@
+@@ -133,111 +156,169 @@
  numpy[-(c + 1) :, d]
  numpy[:, l[-2]]
  numpy[:, ::-1]
@@ -234,6 +234,33 @@
 -for i in (call()): ...
 -for j in (1 + (2 + 3)): ...
 -while(this and that): ...
+-for addr_family, addr_type, addr_proto, addr_canonname, addr_sockaddr in socket.getaddrinfo('google.com', 'http'):
++print(*lambda x: x)
++assert not Test, "Short message"
++assert this is ComplexTest and not requirements.fit_in_a_single_line(
++    force=False
++), "Short message"
++assert parens is TooMany
++for (x,) in (1,), (2,), (3,):
++    ...
++for y in ():
++    ...
++for z in (i for i in (1, 2, 3)):
++    ...
++for i in call():
++    ...
++for j in 1 + (2 + 3):
++    ...
++while this and that:
++    ...
++for (
++    addr_family,
++    addr_type,
++    addr_proto,
++    addr_canonname,
++    addr_sockaddr,
++) in socket.getaddrinfo("google.com", "http"):
+     pass
 -a = aaaa.bbbb.cccc.dddd.eeee.ffff.gggg.hhhh.iiii.jjjj.kkkk.llll.mmmm.nnnn.oooo.pppp in qqqq.rrrr.ssss.tttt.uuuu.vvvv.xxxx.yyyy.zzzz
 -a = aaaa.bbbb.cccc.dddd.eeee.ffff.gggg.hhhh.iiii.jjjj.kkkk.llll.mmmm.nnnn.oooo.pppp not in qqqq.rrrr.ssss.tttt.uuuu.vvvv.xxxx.yyyy.zzzz
 -a = aaaa.bbbb.cccc.dddd.eeee.ffff.gggg.hhhh.iiii.jjjj.kkkk.llll.mmmm.nnnn.oooo.pppp is qqqq.rrrr.ssss.tttt.uuuu.vvvv.xxxx.yyyy.zzzz
@@ -284,24 +311,6 @@
 -    return True
 -if (
 -    ~ aaaaaaaaaaaaaaaa.a + aaaaaaaaaaaaaaaa.b - aaaaaaaaaaaaaaaa.c * aaaaaaaaaaaaaaaa.d @ aaaaaaaaaaaaaaaa.e | aaaaaaaaaaaaaaaa.f & aaaaaaaaaaaaaaaa.g % aaaaaaaaaaaaaaaa.h ^ aaaaaaaaaaaaaaaa.i << aaaaaaaaaaaaaaaa.k >> aaaaaaaaaaaaaaaa.l ** aaaaaaaaaaaaaaaa.m // aaaaaaaaaaaaaaaa.n
-+print(*lambda x: x)
-+assert not Test, "Short message"
-+assert this is ComplexTest and not requirements.fit_in_a_single_line(
-+    force=False
-+), "Short message"
-+assert parens is TooMany
-+for (x,) in (1,), (2,), (3,):
-+    ...
-+for y in ():
-+    ...
-+for z in (i for i in (1, 2, 3)):
-+    ...
-+for i in call():
-+    ...
-+for j in 1 + (2 + 3):
-+    ...
-+while this and that:
-+    ...
 +a = (
 +    aaaa.bbbb.cccc.dddd.eeee.ffff.gggg.hhhh.iiii.jjjj.kkkk.llll.mmmm.nnnn.oooo.pppp
 +    in qqqq.rrrr.ssss.tttt.uuuu.vvvv.xxxx.yyyy.zzzz

diff --git a/tests/data/expression.py b/tests/data/expression.py
index b1fa66bbf3295c59966aa281ddbbdadf54e38ee8..71cf1d9ed24d2266ede970714cec579b173cfe24 100644 (file)
--- a/tests/data/expression.py
+++ b/tests/data/expression.py
@@ -184,6 +184,8 @@ for z in (i for i in (1, 2, 3)): ...
 for i in (call()): ...
 for j in (1 + (2 + 3)): ...
 while(this and that): ...
+for addr_family, addr_type, addr_proto, addr_canonname, addr_sockaddr in socket.getaddrinfo('google.com', 'http'):
+    pass
 a = aaaa.bbbb.cccc.dddd.eeee.ffff.gggg.hhhh.iiii.jjjj.kkkk.llll.mmmm.nnnn.oooo.pppp in qqqq.rrrr.ssss.tttt.uuuu.vvvv.xxxx.yyyy.zzzz
 a = aaaa.bbbb.cccc.dddd.eeee.ffff.gggg.hhhh.iiii.jjjj.kkkk.llll.mmmm.nnnn.oooo.pppp not in qqqq.rrrr.ssss.tttt.uuuu.vvvv.xxxx.yyyy.zzzz
 a = aaaa.bbbb.cccc.dddd.eeee.ffff.gggg.hhhh.iiii.jjjj.kkkk.llll.mmmm.nnnn.oooo.pppp is qqqq.rrrr.ssss.tttt.uuuu.vvvv.xxxx.yyyy.zzzz
@@ -483,6 +485,14 @@ for j in 1 + (2 + 3):
     ...
 while this and that:
     ...
+for (
+    addr_family,
+    addr_type,
+    addr_proto,
+    addr_canonname,
+    addr_sockaddr,
+) in socket.getaddrinfo("google.com", "http"):
+    pass
 a = (
     aaaa.bbbb.cccc.dddd.eeee.ffff.gggg.hhhh.iiii.jjjj.kkkk.llll.mmmm.nnnn.oooo.pppp
     in qqqq.rrrr.ssss.tttt.uuuu.vvvv.xxxx.yyyy.zzzz