From 3a542a96fb59c254d68348c54e04af8fdcab7b4e Mon Sep 17 00:00:00 2001
From: Koichi ITO <koic.ito@gmail.com>
Date: Sat, 21 Jan 2023 00:50:05 +0900
Subject: [PATCH] Fix an error for `Style/Semicolon`

This PR fixes the following error for `Style/Semicolon`
when using a comment containing a semicolon before a block:

```ruby
# ;
foo {
}
```

```console
% bundle exec rubocop --only Style/Semicolon
(snip)

  NoMethodError:
    undefined method `semicolon?' for nil:NilClass
```

No changelog entry because this is a bug by #11465 and not released.
---
 lib/rubocop/cop/style/semicolon.rb       | 2 +-
 spec/rubocop/cop/style/semicolon_spec.rb | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/rubocop/cop/style/semicolon.rb b/lib/rubocop/cop/style/semicolon.rb
index ce2709d33681..5b4dee95cff3 100644
--- a/lib/rubocop/cop/style/semicolon.rb
+++ b/lib/rubocop/cop/style/semicolon.rb
@@ -100,7 +100,7 @@ def exist_semicolon_before_right_curly_brace?(tokens)
         end
 
         def exist_semicolon_after_left_curly_brace?(tokens)
-          tokens[1]&.left_curly_brace? && tokens[2].semicolon?
+          tokens[1]&.left_curly_brace? && tokens[2]&.semicolon?
         end
 
         def register_semicolon(line, column, after_expression, token_before_semicolon = nil)
diff --git a/spec/rubocop/cop/style/semicolon_spec.rb b/spec/rubocop/cop/style/semicolon_spec.rb
index b7e1b00ae284..927b22110798 100644
--- a/spec/rubocop/cop/style/semicolon_spec.rb
+++ b/spec/rubocop/cop/style/semicolon_spec.rb
@@ -142,6 +142,14 @@ module Foo; end
     RUBY
   end
 
+  it 'does not register an offense when using a comment containing a semicolon before a block' do
+    expect_no_offenses(<<~RUBY)
+      # ;
+      foo {
+      }
+    RUBY
+  end
+
   it 'registers an offense for range (`1..42`) with semicolon' do
     expect_offense(<<~RUBY)
       1..42;