From e5d86464b663530e92ee6acd2639652cde7c5442 Mon Sep 17 00:00:00 2001
From: Earlopain <14981592+Earlopain@users.noreply.github.com>
Date: Thu, 7 Mar 2024 21:27:38 +0100
Subject: [PATCH] [Fix #12663] Prevent `Lint/Syntax` being disabled by
 directive comments

This would swallow the syntax error, making it look like the file is all good.
In reality all other cops are not being run.
---
 ...ax_being_disabled_by_directive_comments.md |  1 +
 lib/rubocop/directive_comment.rb              | 18 +++++-----
 spec/rubocop/cli_spec.rb                      | 36 +++++++++++++++++++
 spec/rubocop/comment_config_spec.rb           |  8 ++---
 4 files changed, 50 insertions(+), 13 deletions(-)
 create mode 100644 changelog/fix_lint_syntax_being_disabled_by_directive_comments.md

diff --git a/changelog/fix_lint_syntax_being_disabled_by_directive_comments.md b/changelog/fix_lint_syntax_being_disabled_by_directive_comments.md
new file mode 100644
index 00000000000..ddcae7502f1
--- /dev/null
+++ b/changelog/fix_lint_syntax_being_disabled_by_directive_comments.md
@@ -0,0 +1 @@
+* [#12663](https://github.com/rubocop/rubocop/issues/12663): Fix `Lint/Syntax` getting disabled by `rubocop:disable Lint/Syntax`. ([@earlopain][])
diff --git a/lib/rubocop/directive_comment.rb b/lib/rubocop/directive_comment.rb
index d8bc614ed48..f18e29a277e 100644
--- a/lib/rubocop/directive_comment.rb
+++ b/lib/rubocop/directive_comment.rb
@@ -6,9 +6,11 @@ module RuboCop
   # cops it contains.
   class DirectiveComment
     # @api private
-    REDUNDANT_DIRECTIVE_COP_DEPARTMENT = 'Lint'
+    LINT_DEPARTMENT = 'Lint'
     # @api private
-    REDUNDANT_DIRECTIVE_COP = "#{REDUNDANT_DIRECTIVE_COP_DEPARTMENT}/RedundantCopDisableDirective"
+    LINT_REDUNDANT_DIRECTIVE_COP = "#{LINT_DEPARTMENT}/RedundantCopDisableDirective"
+    # @api private
+    LINT_SYNTAX_COP = "#{LINT_DEPARTMENT}/Syntax"
     # @api private
     COP_NAME_PATTERN = '([A-Z]\w+/)*(?:[A-Z]\w+)'
     # @api private
@@ -118,9 +120,10 @@ def splitted_cops_string
     end
 
     def parsed_cop_names
-      splitted_cops_string.map do |name|
+      cops = splitted_cops_string.map do |name|
         department?(name) ? cop_names_for_department(name) : name
       end.flatten
+      cops - [LINT_SYNTAX_COP]
     end
 
     def department?(name)
@@ -128,17 +131,16 @@ def department?(name)
     end
 
     def all_cop_names
-      exclude_redundant_directive_cop(cop_registry.names)
+      exclude_lint_department_cops(cop_registry.names)
     end
 
     def cop_names_for_department(department)
       names = cop_registry.names_for_department(department)
-      has_redundant_directive_cop = department == REDUNDANT_DIRECTIVE_COP_DEPARTMENT
-      has_redundant_directive_cop ? exclude_redundant_directive_cop(names) : names
+      department == LINT_DEPARTMENT ? exclude_lint_department_cops(names) : names
     end
 
-    def exclude_redundant_directive_cop(cops)
-      cops - [REDUNDANT_DIRECTIVE_COP]
+    def exclude_lint_department_cops(cops)
+      cops - [LINT_REDUNDANT_DIRECTIVE_COP, LINT_SYNTAX_COP]
     end
   end
 end
diff --git a/spec/rubocop/cli_spec.rb b/spec/rubocop/cli_spec.rb
index 015d6ff1b2c..bd736c41622 100644
--- a/spec/rubocop/cli_spec.rb
+++ b/spec/rubocop/cli_spec.rb
@@ -368,6 +368,42 @@ def and_with_args
         $stdout.string.include?('F:  1:  7: Lint/Syntax: unexpected token tINTEGER')
       ).to be(true)
     end
+
+    it '`Lint/Syntax` must be enabled when disabled by directive comment' do
+      create_file('example.rb', <<~RUBY)
+        # rubocop:disable Lint/Syntax
+        1 /// 2
+      RUBY
+
+      expect(cli.run(['--format', 'simple', 'example.rb'])).to eq(1)
+      expect(
+        $stdout.string.include?('F:  2:  7: Lint/Syntax: unexpected token tINTEGER')
+      ).to be(true)
+    end
+
+    it '`Lint/Syntax` must be enabled when disabled by directive department comment' do
+      create_file('example.rb', <<~RUBY)
+        # rubocop:disable Lint
+        1 /// 2
+      RUBY
+
+      expect(cli.run(['--format', 'simple', 'example.rb'])).to eq(1)
+      expect(
+        $stdout.string.include?('F:  2:  7: Lint/Syntax: unexpected token tINTEGER')
+      ).to be(true)
+    end
+
+    it '`Lint/Syntax` must be enabled when disabled by directive all comment' do
+      create_file('example.rb', <<~RUBY)
+        # rubocop:disable all
+        1 /// 2
+      RUBY
+
+      expect(cli.run(['--format', 'simple', 'example.rb'])).to eq(1)
+      expect(
+        $stdout.string.include?('F:  2:  7: Lint/Syntax: unexpected token tINTEGER')
+      ).to be(true)
+    end
   end
 
   describe 'rubocop:disable comment' do
diff --git a/spec/rubocop/comment_config_spec.rb b/spec/rubocop/comment_config_spec.rb
index e5156480a4c..d47ac0ac90b 100644
--- a/spec/rubocop/comment_config_spec.rb
+++ b/spec/rubocop/comment_config_spec.rb
@@ -140,13 +140,11 @@ def disabled_lines_of_cop(cop)
       expect(loop_disabled_lines.include?(20)).to be(false)
     end
 
-    it 'supports disabling all cops except Lint/RedundantCopDisableDirective with keyword all' do
+    it 'supports disabling all cops except Lint/RedundantCopDisableDirective and Lint/Syntax with keyword all' do
       expected_part = (7..8).to_a
 
-      cops = RuboCop::Cop::Registry.all.reject do |klass|
-        klass == RuboCop::Cop::Lint::RedundantCopDisableDirective
-      end
-
+      excluded = [RuboCop::Cop::Lint::RedundantCopDisableDirective, RuboCop::Cop::Lint::Syntax]
+      cops = RuboCop::Cop::Registry.all - excluded
       cops.each do |cop|
         disabled_lines = disabled_lines_of_cop(cop)
         expect(disabled_lines & expected_part).to eq(expected_part)