From cff9c13c426c2b6b03bfa046c2cb3030c05f1214 Mon Sep 17 00:00:00 2001
From: Chandra Kiran G <121796315+kiran-4444@users.noreply.github.com>
Date: Tue, 21 Jan 2025 19:17:06 +0530
Subject: [PATCH] feat: Update RUF055 to do var == value (#15605)

This commit fixes RUF055 rule to format `re.fullmatch(pattern, var)` to
`var == pattern` instead of the current `pattern == var` behaviour. This
is more idiomatic and easy to understand.

## Summary

This changes the current formatting behaviour of `re.fullmatch(pattern,
var)` to format it to `var == pattern` instead of `pattern == var`.

## Test Plan

I used a code file locally to see the updated formatting behaviour.

Fixes https://github.com/astral-sh/ruff/issues/14733
---
 .../src/rules/ruff/rules/unnecessary_regular_expression.rs | 7 ++++++-
 ...r__rules__ruff__tests__preview__RUF055_RUF055_0.py.snap | 5 +++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/crates/ruff_linter/src/rules/ruff/rules/unnecessary_regular_expression.rs b/crates/ruff_linter/src/rules/ruff/rules/unnecessary_regular_expression.rs
index ac99258457..fe263f1926 100644
--- a/crates/ruff_linter/src/rules/ruff/rules/unnecessary_regular_expression.rs
+++ b/crates/ruff_linter/src/rules/ruff/rules/unnecessary_regular_expression.rs
@@ -241,7 +241,12 @@ impl<'a> ReFunc<'a> {
             // pattern in string
             ReFuncKind::Search => Some(self.compare_expr(CmpOp::In)),
             // string == pattern
-            ReFuncKind::Fullmatch => Some(self.compare_expr(CmpOp::Eq)),
+            ReFuncKind::Fullmatch => Some(Expr::Compare(ExprCompare {
+                range: TextRange::default(),
+                left: Box::new(self.string.clone()),
+                ops: Box::new([CmpOp::Eq]),
+                comparators: Box::new([self.pattern.clone()]),
+            })),
             // string.split(pattern)
             ReFuncKind::Split => Some(self.method_expr("split", vec![self.pattern.clone()])),
         }
diff --git a/crates/ruff_linter/src/rules/ruff/snapshots/ruff_linter__rules__ruff__tests__preview__RUF055_RUF055_0.py.snap b/crates/ruff_linter/src/rules/ruff/snapshots/ruff_linter__rules__ruff__tests__preview__RUF055_RUF055_0.py.snap
index fc63097a61..f778d0a023 100644
--- a/crates/ruff_linter/src/rules/ruff/snapshots/ruff_linter__rules__ruff__tests__preview__RUF055_RUF055_0.py.snap
+++ b/crates/ruff_linter/src/rules/ruff/snapshots/ruff_linter__rules__ruff__tests__preview__RUF055_RUF055_0.py.snap
@@ -1,5 +1,6 @@
 ---
 source: crates/ruff_linter/src/rules/ruff/mod.rs
+snapshot_kind: text
 ---
 RUF055_0.py:6:1: RUF055 [*] Plain string pattern passed to `re` function
   |
@@ -68,14 +69,14 @@ RUF055_0.py:34:4: RUF055 [*] Plain string pattern passed to `re` function
 35 |     pass
 36 | re.fullmatch("abc", s)  # this should not be replaced
    |
-   = help: Replace with `"abc" == s`
+   = help: Replace with `s == "abc"`
 
 ℹ Safe fix
 31 31 | re.search("abc", s)  # this should not be replaced
 32 32 | 
 33 33 | # this should be replaced with "abc" == s
 34    |-if re.fullmatch("abc", s):
-   34 |+if "abc" == s:
+   34 |+if s == "abc":
 35 35 |     pass
 36 36 | re.fullmatch("abc", s)  # this should not be replaced
 37 37 |