Add Sorbet's typed sigil as a magic comment

changelog/new_add_sorbets_typed_sigil_as_a_magic_comment.md

@@ -0,0 +1 @@
+* [#10620](https://github.com/rubocop/rubocop/pull/10620): Add Sorbet's `typed` sigil as a magic comment. ([@zachahn][])

lib/rubocop/magic_comment.rb

@@ -11,7 +11,8 @@ class MagicComment
     KEYWORDS = {
       encoding: '(?:en)?coding',
       frozen_string_literal: 'frozen[_-]string[_-]literal',
-      shareable_constant_value: 'shareable[_-]constant[_-]value'
+      shareable_constant_value: 'shareable[_-]constant[_-]value',
+      typed: 'typed'
     }.freeze
 
     # Detect magic comment format and pass it to the appropriate wrapper.
@@ -33,7 +34,10 @@ def initialize(comment)
     end
 
     def any?
-      frozen_string_literal_specified? || encoding_specified? || shareable_constant_value_specified?
+      frozen_string_literal_specified? ||
+        encoding_specified? ||
+        shareable_constant_value_specified? ||
+        typed_specified?
     end
 
     def valid?
@@ -101,6 +105,17 @@ def encoding_specified?
       specified?(encoding)
     end
 
+    # Was the Sorbet `typed` sigil specified?
+    #
+    # @return [Boolean]
+    def typed_specified?
+      specified?(extract_typed)
+    end
+
+    def typed
+      extract_typed
+    end
+
     private
 
     def specified?(value)
@@ -187,6 +202,9 @@ def extract_frozen_string_literal
       def extract_shareable_constant_value
         match(KEYWORDS[:shareable_constant_value])
       end
+
+      # Emacs comments cannot specify Sorbet typechecking behavior.
+      def extract_typed; end
     end
 
     # Wrapper for Vim style magic comments.
@@ -222,6 +240,9 @@ def frozen_string_literal; end
 
       # Vim comments cannot specify shareable constant values behavior.
       def shareable_constant_value; end
+
+      # Vim comments cannot specify Sorbet typechecking behavior.
+      def extract_typed; end
     end
 
     # Wrapper for regular magic comments not bound to an editor.
@@ -268,6 +289,10 @@ def extract_frozen_string_literal
       def extract_shareable_constant_value
         extract(/\A\s*#\s*#{KEYWORDS[:shareable_constant_value]}:\s*(#{TOKEN})\s*\z/io)
       end
+
+      def extract_typed
+        extract(/\A\s*#\s*#{KEYWORDS[:typed]}:\s*(#{TOKEN})\s*\z/io)
+      end
     end
   end
 end

spec/rubocop/cop/layout/empty_line_after_magic_comment_spec.rb

@@ -15,6 +15,20 @@ class Foo; end
     RUBY
   end
 
+  it 'registers an offense when code that immediately follows typed comment' do
+    expect_offense(<<~RUBY)
+      # typed: true
+      class Foo; end
+      ^ Add an empty line after magic comments.
+    RUBY
+
+    expect_correction(<<~RUBY)
+      # typed: true
+
+      class Foo; end
+    RUBY
+  end
+
   it 'registers an offense for documentation immediately following comment' do
     expect_offense(<<~RUBY)
       # frozen_string_literal: true
@@ -72,6 +86,22 @@ class Foo; end
     RUBY
   end
 
+  it 'accepts magic comment with typed' do
+    expect_no_offenses(<<~RUBY)
+      # frozen_string_literal: true
+      # typed: true
+
+      class Foo; end
+    RUBY
+
+    expect_no_offenses(<<~RUBY)
+      # typed: true
+      # frozen_string_literal: true
+
+      class Foo; end
+    RUBY
+  end
+
   it 'registers offense when frozen_string_literal used with shareable_constant_value without empty line' do
     expect_offense(<<~RUBY)
       # frozen_string_literal: true

spec/rubocop/magic_comment_spec.rb

@@ -5,6 +5,7 @@
     encoding = expectations[:encoding]
     frozen_string = expectations[:frozen_string_literal]
     shareable_constant_value = expectations[:shareable_constant_value]
+    typed = expectations[:typed]
 
     it "returns #{encoding.inspect} for encoding when comment is #{comment}" do
       expect(described_class.parse(comment).encoding).to eql(encoding)
@@ -19,6 +20,10 @@
       expect(described_class.parse(comment)
                             .shareable_constant_value).to eql(shareable_constant_value)
     end
+
+    it "returns #{typed.inspect} for typed when comment is #{comment}" do
+      expect(described_class.parse(comment).typed).to eql(typed)
+    end
   end
 
   include_examples 'magic comment', '#'
@@ -69,6 +74,22 @@
 
   include_examples 'magic comment', '# xyz shareable_constant_value: literal xyz'
 
+  include_examples 'magic comment', '# typed: ignore', typed: 'ignore'
+
+  include_examples 'magic comment', '# typed: false', typed: 'false'
+
+  include_examples 'magic comment', '# typed: true', typed: 'true'
+
+  include_examples 'magic comment', '# typed: strict', typed: 'strict'
+
+  include_examples 'magic comment', '# typed: strong', typed: 'strong'
+
+  include_examples 'magic comment', '#typed:strict', typed: 'strict'
+
+  include_examples 'magic comment', '#    typed:strict', typed: 'strict'
+
+  include_examples 'magic comment', '# @typed'
+
   include_examples(
     'magic comment',
     '# shareable_constant_value: experimental_everything',
@@ -125,9 +146,8 @@
 
   include_examples(
     'magic comment',
-    '# -*- coding: ASCII-8BIT; frozen_string_literal: true -*-',
-    encoding: 'ascii-8bit',
-    frozen_string_literal: true
+    '# -*- coding: ASCII-8BIT; typed: strict -*-',
+    encoding: 'ascii-8bit'
   )
 
   include_examples 'magic comment',
@@ -144,6 +164,10 @@
                    '#vim: filetype=ruby, fileencoding=ascii-8bit',
                    encoding: 'ascii-8bit'
 
+  include_examples 'magic comment',
+                   '#vim: filetype=ruby, fileencoding=ascii-8bit, typed=strict',
+                   encoding: 'ascii-8bit'
+
   include_examples(
     'magic comment',
     '# coding: utf-8 vim: filetype=ruby, fileencoding=ascii-8bit',