From f5b14b1afd1ceb240c0b46a2cd3e380a4da857df Mon Sep 17 00:00:00 2001
From: Jelle Zijlstra <jelle.zijlstra@gmail.com>
Date: Fri, 22 Feb 2019 22:00:40 -0800
Subject: [PATCH]  split long del statements into multiple lines (#698)

Fixes #693
---
 README.md             |  6 ++++--
 black.py              | 12 +++++++++++-
 tests/data/cantfit.py |  8 ++++++++
 3 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index b25f64f..57272ae 100644
--- a/README.md
+++ b/README.md
@@ -944,10 +944,12 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md).
 
 ### 19.2b0
 
-* *Black* no longer normalizes numeric literals to include `_` separators.
+* long `del` statements are now split into multiple lines (#698)
+
+* *Black* no longer normalizes numeric literals to include `_` separators (#696)
 
 * new option `--target-version` to control which Python versions
-  *Black*-formatted code should target
+  *Black*-formatted code should target (#618)
 
 ### 18.9b0
 
diff --git a/black.py b/black.py
index 34bd59e..8f50d3e 100644
--- a/black.py
+++ b/black.py
@@ -1646,6 +1646,7 @@ class LineGenerator(Visitor[Line]):
         self.visit_expr_stmt = partial(v, keywords=Ø, parens=ASSIGNMENTS)
         self.visit_return_stmt = partial(v, keywords={"return"}, parens={"return"})
         self.visit_import_from = partial(v, keywords=Ø, parens={"import"})
+        self.visit_del_stmt = partial(v, keywords=Ø, parens={"del"})
         self.visit_async_funcdef = self.visit_async_stmt
         self.visit_decorated = self.visit_decorators
 
@@ -3350,7 +3351,16 @@ def assert_equivalent(src: str, dst: str) -> None:
 
             if isinstance(value, list):
                 for item in value:
-                    if isinstance(item, ast.AST):
+                    # Ignore nested tuples within del statements, because we may insert
+                    # parentheses and they change the AST.
+                    if (
+                        field == "targets"
+                        and isinstance(node, ast.Delete)
+                        and isinstance(item, ast.Tuple)
+                    ):
+                        for item in item.elts:
+                            yield from _v(item, depth + 2)
+                    elif isinstance(item, ast.AST):
                         yield from _v(item, depth + 2)
 
             elif isinstance(value, ast.AST):
diff --git a/tests/data/cantfit.py b/tests/data/cantfit.py
index 2a7cde3..0ab1575 100644
--- a/tests/data/cantfit.py
+++ b/tests/data/cantfit.py
@@ -36,6 +36,7 @@ for key in """
     if key in self.connect_kwargs:
         raise ValueError(err.format(key))
 concatenated_strings = "some strings that are" "concatenated implicitly, so if you put them on separate" "lines it will fit"
+del concatenated_strings, string_variable_name, normal_function_name, normal_name, need_more_to_make_the_line_long_enough
 
 
 # output
@@ -91,3 +92,10 @@ concatenated_strings = (
     "concatenated implicitly, so if you put them on separate"
     "lines it will fit"
 )
+del (
+    concatenated_strings,
+    string_variable_name,
+    normal_function_name,
+    normal_name,
+    need_more_to_make_the_line_long_enough,
+)
-- 
2.39.5