[Fix rubocop#9328] Recognize shareable_constant_value magic comment

changelog/change_recognize_shareable_constant_value_magic.md

@@ -0,0 +1 @@
+* [#9328](https://github.com/rubocop-hq/rubocop/issues/9328): Recognize shareable_constant_value magic comment. ([@caalberts][])

lib/rubocop.rb

@@ -113,6 +113,7 @@
 require_relative 'rubocop/cop/mixin/rational_literal'
 require_relative 'rubocop/cop/mixin/rescue_node'
 require_relative 'rubocop/cop/mixin/safe_assignment'
+require_relative 'rubocop/cop/mixin/shareable_constant_value'
 require_relative 'rubocop/cop/mixin/space_after_punctuation'
 require_relative 'rubocop/cop/mixin/space_before_punctuation'
 require_relative 'rubocop/cop/mixin/surrounding_space'

lib/rubocop/cop/mixin/shareable_constant_value.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    # Common functionality for dealing with shareable constant value.
+    module ShareableConstantValue
+      module_function
+
+      LITERAL = :literal
+      EXPERIMENTAL_ANYTHING = :experimental_everything
+
+      def shareable_constant_value?
+        target_ruby_version >= 3.0 && shareable_constant_value_comment_exists?
+      end
+
+      def shareable_constant_value_comment_exists?
+        leading_comments.any? do |line|
+          shareable_constant_value = MagicComment.parse(line).shareable_constant_value
+
+          [LITERAL, EXPERIMENTAL_ANYTHING].include?(shareable_constant_value)
+        end
+      end
+
+      private
+
+      def leading_comments
+        processed_source
+          .tokens
+          .take_while(&:comment?)
+          .map(&:text)
+      end
+    end
+  end
+end

lib/rubocop/cop/style/mutable_constant.rb

@@ -54,6 +54,7 @@ module Style
       #   end.freeze
       class MutableConstant < Base
         include FrozenStringLiteral
+        include ShareableConstantValue
         include ConfigurableEnforcedStyle
         extend AutoCorrector
 
@@ -83,6 +84,7 @@ def on_assignment(value)
         end
 
         def strict_check(value)
+          return if shareable_constant_value?
           return if immutable_literal?(value)
           return if operation_produces_immutable_object?(value)
           return if frozen_string_literal?(value)
@@ -93,6 +95,8 @@ def strict_check(value)
         end
 
         def check(value)
+          return if shareable_constant_value?
+
           range_enclosed_in_parentheses = range_enclosed_in_parentheses?(value)
 
           return unless mutable_literal?(value) ||

lib/rubocop/magic_comment.rb

@@ -84,7 +84,13 @@ def frozen_string_literal
     #
     # @return [String] for shareable_constant_value config
     def shareable_constant_value
-      extract_shareable_constant_value
+      return unless (setting = extract_shareable_constant_value)
+
+      case setting
+      when 'none' then nil
+      else
+        setting.to_sym
+      end
     end
 
     def encoding_specified?
@@ -166,7 +172,7 @@ def extract_frozen_string_literal
       end
 
       def extract_shareable_constant_value
-        match('shareable[_-]constant[_-]values')
+        match('shareable[_-]constant[_-]value')
       end
     end
 

spec/rubocop/cop/style/mutable_constant_spec.rb

@@ -157,6 +157,61 @@
           RUBY
         end
       end
+
+      context 'when using shareable_constant_value: literal' do
+        let(:prefix) { '# shareable_constant_value: literal' }
+
+        it_behaves_like 'immutable objects', '[1, 2, 3]'
+        it_behaves_like 'immutable objects', '%w(a b c)'
+        it_behaves_like 'immutable objects', '{ a: 1, b: 2 }'
+        it_behaves_like 'immutable objects', "'str'"
+        it_behaves_like 'immutable objects', '"top#{1 + 2}"'
+        it_behaves_like 'immutable objects', '1'
+        it_behaves_like 'immutable objects', '1.5'
+        it_behaves_like 'immutable objects', ':sym'
+        it_behaves_like 'immutable objects', 'FOO + BAR'
+        it_behaves_like 'immutable objects', 'FOO - BAR'
+        it_behaves_like 'immutable objects', "'foo' + 'bar'"
+        it_behaves_like 'immutable objects', "ENV['foo']"
+        it_behaves_like 'immutable objects', "::ENV['foo']"
+      end
+
+      context 'when using shareable_constant_value: experimental_everything' do
+        let(:prefix) { '# shareable_constant_value: experimental_everything' }
+
+        it_behaves_like 'immutable objects', '[1, 2, 3]'
+        it_behaves_like 'immutable objects', '%w(a b c)'
+        it_behaves_like 'immutable objects', '{ a: 1, b: 2 }'
+        it_behaves_like 'immutable objects', "'str'"
+        it_behaves_like 'immutable objects', '"top#{1 + 2}"'
+        it_behaves_like 'immutable objects', '1'
+        it_behaves_like 'immutable objects', '1.5'
+        it_behaves_like 'immutable objects', ':sym'
+        it_behaves_like 'immutable objects', 'FOO + BAR'
+        it_behaves_like 'immutable objects', 'FOO - BAR'
+        it_behaves_like 'immutable objects', "'foo' + 'bar'"
+        it_behaves_like 'immutable objects', "ENV['foo']"
+        it_behaves_like 'immutable objects', "::ENV['foo']"
+      end
+
+      context 'when using shareable_constant_value: none' do
+        let(:prefix) { '# shareable_constant_value: none' }
+
+        it_behaves_like 'mutable objects', '[1, 2, 3]'
+        it_behaves_like 'mutable objects', '%w(a b c)'
+        it_behaves_like 'mutable objects', '{ a: 1, b: 2 }'
+        it_behaves_like 'mutable objects', "'str'"
+        it_behaves_like 'mutable objects', '"top#{1 + 2}"'
+
+        it_behaves_like 'immutable objects', '1'
+        it_behaves_like 'immutable objects', '1.5'
+        it_behaves_like 'immutable objects', ':sym'
+        it_behaves_like 'immutable objects', 'FOO + BAR'
+        it_behaves_like 'immutable objects', 'FOO - BAR'
+        it_behaves_like 'immutable objects', "'foo' + 'bar'"
+        it_behaves_like 'immutable objects', "ENV['foo']"
+        it_behaves_like 'immutable objects', "::ENV['foo']"
+      end
     end
 
     context 'Ruby 2.7 or lower', :ruby27 do
@@ -220,6 +275,44 @@
           RUBY
         end
       end
+
+      context 'when using shareable_constant_value: literal' do
+        let(:prefix) { '# shareable_constant_value: literal' }
+
+        it_behaves_like 'mutable objects', '[1, 2, 3]'
+        it_behaves_like 'mutable objects', '%w(a b c)'
+        it_behaves_like 'mutable objects', '{ a: 1, b: 2 }'
+        it_behaves_like 'mutable objects', "'str'"
+        it_behaves_like 'mutable objects', '"top#{1 + 2}"'
+
+        it_behaves_like 'immutable objects', '1'
+        it_behaves_like 'immutable objects', '1.5'
+        it_behaves_like 'immutable objects', ':sym'
+        it_behaves_like 'immutable objects', 'FOO + BAR'
+        it_behaves_like 'immutable objects', 'FOO - BAR'
+        it_behaves_like 'immutable objects', "'foo' + 'bar'"
+        it_behaves_like 'immutable objects', "ENV['foo']"
+        it_behaves_like 'immutable objects', "::ENV['foo']"
+      end
+
+      context 'when using shareable_constant_value: experimental_everything' do
+        let(:prefix) { '# shareable_constant_value: experimental_everything' }
+
+        it_behaves_like 'mutable objects', '[1, 2, 3]'
+        it_behaves_like 'mutable objects', '%w(a b c)'
+        it_behaves_like 'mutable objects', '{ a: 1, b: 2 }'
+        it_behaves_like 'mutable objects', "'str'"
+        it_behaves_like 'mutable objects', '"top#{1 + 2}"'
+
+        it_behaves_like 'immutable objects', '1'
+        it_behaves_like 'immutable objects', '1.5'
+        it_behaves_like 'immutable objects', ':sym'
+        it_behaves_like 'immutable objects', 'FOO + BAR'
+        it_behaves_like 'immutable objects', 'FOO - BAR'
+        it_behaves_like 'immutable objects', "'foo' + 'bar'"
+        it_behaves_like 'immutable objects', "ENV['foo']"
+        it_behaves_like 'immutable objects', "::ENV['foo']"
+      end
     end
 
     context 'when the constant is a frozen string literal' do
@@ -501,5 +594,162 @@ def assignment?
 
       it_behaves_like 'mutable objects', '"#{a}"'
     end
+
+    context 'Ruby 3.0 or higher', :ruby30 do
+      context 'when using shareable_constant_value: literal' do
+        let(:prefix) { '# shareable_constant_value: literal' }
+
+        it_behaves_like 'immutable objects', '[1, 2, 3]'
+        it_behaves_like 'immutable objects', '%w(a b c)'
+        it_behaves_like 'immutable objects', '{ a: 1, b: 2 }'
+        it_behaves_like 'immutable objects', "'str'"
+        it_behaves_like 'immutable objects', '"top#{1 + 2}"'
+        it_behaves_like 'immutable objects', 'Something.new'
+        it_behaves_like 'immutable objects', '1'
+        it_behaves_like 'immutable objects', '1.5'
+        it_behaves_like 'immutable objects', ':sym'
+        it_behaves_like 'immutable objects', "ENV['foo']"
+        it_behaves_like 'immutable objects', "::ENV['foo']"
+        it_behaves_like 'immutable objects', 'OTHER_CONST'
+        it_behaves_like 'immutable objects', '::OTHER_CONST'
+        it_behaves_like 'immutable objects', 'Namespace::OTHER_CONST'
+        it_behaves_like 'immutable objects', '::Namespace::OTHER_CONST'
+        it_behaves_like 'immutable objects', 'Struct.new'
+        it_behaves_like 'immutable objects', '::Struct.new'
+        it_behaves_like 'immutable objects', 'Struct.new(:a, :b)'
+        it_behaves_like 'immutable objects', <<~RUBY
+          Struct.new(:node) do
+            def assignment?
+              true
+            end
+          end
+        RUBY
+      end
+
+      context 'when using shareable_constant_value: experimental_everything' do
+        let(:prefix) { '# shareable_constant_value: experimental_everything' }
+
+        it_behaves_like 'immutable objects', '[1, 2, 3]'
+        it_behaves_like 'immutable objects', '%w(a b c)'
+        it_behaves_like 'immutable objects', '{ a: 1, b: 2 }'
+        it_behaves_like 'immutable objects', "'str'"
+        it_behaves_like 'immutable objects', '"top#{1 + 2}"'
+        it_behaves_like 'immutable objects', 'Something.new'
+        it_behaves_like 'immutable objects', '1'
+        it_behaves_like 'immutable objects', '1.5'
+        it_behaves_like 'immutable objects', ':sym'
+        it_behaves_like 'immutable objects', "ENV['foo']"
+        it_behaves_like 'immutable objects', "::ENV['foo']"
+        it_behaves_like 'immutable objects', 'OTHER_CONST'
+        it_behaves_like 'immutable objects', '::OTHER_CONST'
+        it_behaves_like 'immutable objects', 'Namespace::OTHER_CONST'
+        it_behaves_like 'immutable objects', '::Namespace::OTHER_CONST'
+        it_behaves_like 'immutable objects', 'Struct.new'
+        it_behaves_like 'immutable objects', '::Struct.new'
+        it_behaves_like 'immutable objects', 'Struct.new(:a, :b)'
+        it_behaves_like 'immutable objects', <<~RUBY
+          Struct.new(:node) do
+            def assignment?
+              true
+            end
+          end
+        RUBY
+      end
+
+      context 'when using shareable_constant_value: none' do
+        let(:prefix) { '# shareable_constant_value: none' }
+
+        it_behaves_like 'mutable objects', '[1, 2, 3]'
+        it_behaves_like 'mutable objects', '%w(a b c)'
+        it_behaves_like 'mutable objects', '{ a: 1, b: 2 }'
+        it_behaves_like 'mutable objects', "'str'"
+        it_behaves_like 'mutable objects', '"top#{1 + 2}"'
+        it_behaves_like 'mutable objects', 'Something.new'
+
+        it_behaves_like 'immutable objects', '1'
+        it_behaves_like 'immutable objects', '1.5'
+        it_behaves_like 'immutable objects', ':sym'
+        it_behaves_like 'immutable objects', "ENV['foo']"
+        it_behaves_like 'immutable objects', "::ENV['foo']"
+        it_behaves_like 'immutable objects', 'OTHER_CONST'
+        it_behaves_like 'immutable objects', '::OTHER_CONST'
+        it_behaves_like 'immutable objects', 'Namespace::OTHER_CONST'
+        it_behaves_like 'immutable objects', '::Namespace::OTHER_CONST'
+        it_behaves_like 'immutable objects', 'Struct.new'
+        it_behaves_like 'immutable objects', '::Struct.new'
+        it_behaves_like 'immutable objects', 'Struct.new(:a, :b)'
+        it_behaves_like 'immutable objects', <<~RUBY
+          Struct.new(:node) do
+            def assignment?
+              true
+            end
+          end
+        RUBY
+      end
+    end
+
+    context 'Ruby 2.7 or lower', :ruby27 do
+      context 'when using shareable_constant_value: literal' do
+        let(:prefix) { '# shareable_constant_value: literal' }
+
+        it_behaves_like 'mutable objects', '[1, 2, 3]'
+        it_behaves_like 'mutable objects', '%w(a b c)'
+        it_behaves_like 'mutable objects', '{ a: 1, b: 2 }'
+        it_behaves_like 'mutable objects', "'str'"
+        it_behaves_like 'mutable objects', '"top#{1 + 2}"'
+        it_behaves_like 'mutable objects', 'Something.new'
+
+        it_behaves_like 'immutable objects', '1'
+        it_behaves_like 'immutable objects', '1.5'
+        it_behaves_like 'immutable objects', ':sym'
+        it_behaves_like 'immutable objects', "ENV['foo']"
+        it_behaves_like 'immutable objects', "::ENV['foo']"
+        it_behaves_like 'immutable objects', 'OTHER_CONST'
+        it_behaves_like 'immutable objects', '::OTHER_CONST'
+        it_behaves_like 'immutable objects', 'Namespace::OTHER_CONST'
+        it_behaves_like 'immutable objects', '::Namespace::OTHER_CONST'
+        it_behaves_like 'immutable objects', 'Struct.new'
+        it_behaves_like 'immutable objects', '::Struct.new'
+        it_behaves_like 'immutable objects', 'Struct.new(:a, :b)'
+        it_behaves_like 'immutable objects', <<~RUBY
+          Struct.new(:node) do
+            def assignment?
+              true
+            end
+          end
+        RUBY
+      end
+
+      context 'when using shareable_constant_value: experimental_everything' do
+        let(:prefix) { '# shareable_constant_value: experimental_everything' }
+
+        it_behaves_like 'mutable objects', '[1, 2, 3]'
+        it_behaves_like 'mutable objects', '%w(a b c)'
+        it_behaves_like 'mutable objects', '{ a: 1, b: 2 }'
+        it_behaves_like 'mutable objects', "'str'"
+        it_behaves_like 'mutable objects', '"top#{1 + 2}"'
+        it_behaves_like 'mutable objects', 'Something.new'
+
+        it_behaves_like 'immutable objects', '1'
+        it_behaves_like 'immutable objects', '1.5'
+        it_behaves_like 'immutable objects', ':sym'
+        it_behaves_like 'immutable objects', "ENV['foo']"
+        it_behaves_like 'immutable objects', "::ENV['foo']"
+        it_behaves_like 'immutable objects', 'OTHER_CONST'
+        it_behaves_like 'immutable objects', '::OTHER_CONST'
+        it_behaves_like 'immutable objects', 'Namespace::OTHER_CONST'
+        it_behaves_like 'immutable objects', '::Namespace::OTHER_CONST'
+        it_behaves_like 'immutable objects', 'Struct.new'
+        it_behaves_like 'immutable objects', '::Struct.new'
+        it_behaves_like 'immutable objects', 'Struct.new(:a, :b)'
+        it_behaves_like 'immutable objects', <<~RUBY
+          Struct.new(:node) do
+            def assignment?
+              true
+            end
+          end
+        RUBY
+      end
+    end
   end
 end