From c165e90a388f663d01fecd4b588d42aff3474be1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89tienne=20Barri=C3=A9?= <etienne.barrie@gmail.com>
Date: Thu, 29 Apr 2021 16:47:21 -0400
Subject: [PATCH] Don't autocorrect global variable interpolation

Global variable interpolation is autocorrected, adding escaping:

'#$foo' is autocorrected to "\#$foo"
---
 changelog/fix_dont_autocorrect_global_variable.md | 1 +
 lib/rubocop/cop/mixin/string_literals_help.rb     | 2 +-
 spec/rubocop/cop/style/string_literals_spec.rb    | 4 +++-
 3 files changed, 5 insertions(+), 2 deletions(-)
 create mode 100644 changelog/fix_dont_autocorrect_global_variable.md

diff --git a/changelog/fix_dont_autocorrect_global_variable.md b/changelog/fix_dont_autocorrect_global_variable.md
new file mode 100644
index 00000000000..f7a3ff8c518
--- /dev/null
+++ b/changelog/fix_dont_autocorrect_global_variable.md
@@ -0,0 +1 @@
+* [#9751](https://github.com/rubocop/rubocop/pull/9751): `Style/StringLiteral` doesn't autocorrect global variable interpolation. ([@etiennebarrie][])
diff --git a/lib/rubocop/cop/mixin/string_literals_help.rb b/lib/rubocop/cop/mixin/string_literals_help.rb
index 455e93939d2..5dc088d371e 100644
--- a/lib/rubocop/cop/mixin/string_literals_help.rb
+++ b/lib/rubocop/cop/mixin/string_literals_help.rb
@@ -15,7 +15,7 @@ def wrong_quotes?(node)
         if style == :single_quotes
           !double_quotes_required?(src)
         else
-          !/" | \\[^'\\] | \#(@|\{)/x.match?(src)
+          !/" | \\[^'\\] | \#[@{$]/x.match?(src)
         end
       end
     end
diff --git a/spec/rubocop/cop/style/string_literals_spec.rb b/spec/rubocop/cop/style/string_literals_spec.rb
index bbd276bcef1..b6dd68f36b0 100644
--- a/spec/rubocop/cop/style/string_literals_spec.rb
+++ b/spec/rubocop/cop/style/string_literals_spec.rb
@@ -264,10 +264,12 @@
         a = '\n'
         b = '"'
         c = '#{x}'
+        d = '#@x'
+        e = '#$x'
       RUBY
     end
 
-    it 'flags single quotes with plain # (not #@var or #{interpolation}' do
+    it 'flags single quotes with plain # (not #@var or #{interpolation} or #$global' do
       expect_offense(<<~RUBY)
         a = 'blah #'
             ^^^^^^^^ Prefer double-quoted strings unless you need single quotes to avoid extra backslashes for escaping.