From 227ff62a4e802fd3e5f675f840835088ce5462e3 Mon Sep 17 00:00:00 2001
From: Charlie Marsh <charlie.r.marsh@gmail.com>
Date: Wed, 22 Feb 2023 22:10:24 -0500
Subject: [PATCH] Don't touch tuple brackets after `in` (#3160)

---
 .../ruff_python_formatter/src/parentheses.rs  |   4 +-
 ...lack_test__remove_for_brackets_py.snap.new | 111 ++++++++++++++++++
 2 files changed, 114 insertions(+), 1 deletion(-)
 create mode 100644 crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__remove_for_brackets_py.snap.new

diff --git a/crates/ruff_python_formatter/src/parentheses.rs b/crates/ruff_python_formatter/src/parentheses.rs
index 502eec7f73..80b5dd7170 100644
--- a/crates/ruff_python_formatter/src/parentheses.rs
+++ b/crates/ruff_python_formatter/src/parentheses.rs
@@ -68,7 +68,9 @@ impl<'a> Visitor<'a> for ParenthesesNormalizer {
             }
             StmtKind::For { target, iter, .. } | StmtKind::AsyncFor { target, iter, .. } => {
                 use_inferred_parens(target);
-                use_inferred_parens(iter);
+                if !matches!(iter.node, ExprKind::Tuple { .. }) {
+                    use_inferred_parens(iter);
+                }
             }
             StmtKind::While { test, .. } => {
                 use_inferred_parens(test);
diff --git a/crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__remove_for_brackets_py.snap.new b/crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__remove_for_brackets_py.snap.new
new file mode 100644
index 0000000000..51d74eea0f
--- /dev/null
+++ b/crates/ruff_python_formatter/src/snapshots/ruff_python_formatter__tests__black_test__remove_for_brackets_py.snap.new
@@ -0,0 +1,111 @@
+---
+source: crates/ruff_python_formatter/src/lib.rs
+assertion_line: 146
+expression: snapshot
+input_file: crates/ruff_python_formatter/resources/test/fixtures/black/simple_cases/remove_for_brackets.py
+---
+## Input
+
+```py
+# Only remove tuple brackets after `for`
+for (k, v) in d.items():
+    print(k, v)
+
+# Don't touch tuple brackets after `in`
+for module in (core, _unicodefun):
+    if hasattr(module, "_verify_python3_env"):
+        module._verify_python3_env = lambda: None
+
+# Brackets remain for long for loop lines
+for (why_would_anyone_choose_to_name_a_loop_variable_with_a_name_this_long, i_dont_know_but_we_should_still_check_the_behaviour_if_they_do) in d.items():
+    print(k, v)
+
+for (k, v) in dfkasdjfldsjflkdsjflkdsjfdslkfjldsjfgkjdshgkljjdsfldgkhsdofudsfudsofajdslkfjdslkfjldisfjdffjsdlkfjdlkjjkdflskadjldkfjsalkfjdasj.items():
+    print(k, v)
+
+# Test deeply nested brackets
+for (((((k, v))))) in d.items():
+    print(k, v)
+```
+
+## Black Differences
+
+```diff
+--- Black
++++ Ruff
+@@ -17,9 +17,7 @@
+ for (
+     k,
+     v,
+-) in (
+-    dfkasdjfldsjflkdsjflkdsjfdslkfjldsjfgkjdshgkljjdsfldgkhsdofudsfudsofajdslkfjdslkfjldisfjdffjsdlkfjdlkjjkdflskadjldkfjsalkfjdasj.items()
+-):
++) in dfkasdjfldsjflkdsjflkdsjfdslkfjldsjfgkjdshgkljjdsfldgkhsdofudsfudsofajdslkfjdslkfjldisfjdffjsdlkfjdlkjjkdflskadjldkfjsalkfjdasj.items():
+     print(k, v)
+ 
+ # Test deeply nested brackets
+```
+
+## Ruff Output
+
+```py
+# Only remove tuple brackets after `for`
+for k, v in d.items():
+    print(k, v)
+
+# Don't touch tuple brackets after `in`
+for module in (core, _unicodefun):
+    if hasattr(module, "_verify_python3_env"):
+        module._verify_python3_env = lambda: None
+
+# Brackets remain for long for loop lines
+for (
+    why_would_anyone_choose_to_name_a_loop_variable_with_a_name_this_long,
+    i_dont_know_but_we_should_still_check_the_behaviour_if_they_do,
+) in d.items():
+    print(k, v)
+
+for (
+    k,
+    v,
+) in dfkasdjfldsjflkdsjflkdsjfdslkfjldsjfgkjdshgkljjdsfldgkhsdofudsfudsofajdslkfjdslkfjldisfjdffjsdlkfjdlkjjkdflskadjldkfjsalkfjdasj.items():
+    print(k, v)
+
+# Test deeply nested brackets
+for k, v in d.items():
+    print(k, v)
+```
+
+## Black Output
+
+```py
+# Only remove tuple brackets after `for`
+for k, v in d.items():
+    print(k, v)
+
+# Don't touch tuple brackets after `in`
+for module in (core, _unicodefun):
+    if hasattr(module, "_verify_python3_env"):
+        module._verify_python3_env = lambda: None
+
+# Brackets remain for long for loop lines
+for (
+    why_would_anyone_choose_to_name_a_loop_variable_with_a_name_this_long,
+    i_dont_know_but_we_should_still_check_the_behaviour_if_they_do,
+) in d.items():
+    print(k, v)
+
+for (
+    k,
+    v,
+) in (
+    dfkasdjfldsjflkdsjflkdsjfdslkfjldsjfgkjdshgkljjdsfldgkhsdofudsfudsofajdslkfjdslkfjldisfjdffjsdlkfjdlkjjkdflskadjldkfjsalkfjdasj.items()
+):
+    print(k, v)
+
+# Test deeply nested brackets
+for k, v in d.items():
+    print(k, v)
+```
+
+