Add RegexpNode#options

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## master (unreleased)
 
+### New features
+
+* [#124](https://github.com/rubocop-hq/rubocop-ast/pull/124): Add `RegexpNode#options`. ([@owst][])
+
 ## 0.5.1 (2020-09-25)
 
 ### Bug fixes

lib/rubocop/ast/node/regexp_node.rb

@@ -14,19 +14,23 @@ class RegexpNode < Node
         o: 0
       }.freeze
 
-      # Note: The 'o' option is ignored.
-      #
       # @return [Regexp] a regexp of this node
       def to_regexp
-        option = regopt.children.map { |opt| OPTIONS.fetch(opt) }.inject(:|)
-        Regexp.new(content, option)
+        Regexp.new(content, options)
       end
 
       # @return [RuboCop::AST::Node] a regopt node
       def regopt
         children.last
       end
 
+      # Note: The 'o' option is ignored.
+      #
+      # @return [Integer] the Regexp option bits as returned by Regexp#options
+      def options
+        regopt.children.map { |opt| OPTIONS.fetch(opt) }.inject(0, :|)
+      end
+
       # @return [String] a string of regexp content
       def content
         children.select(&:str_type?).map(&:str_content).join

spec/rubocop/ast/regexp_node_spec.rb

@@ -101,6 +101,43 @@
     end
   end
 
+  describe '#options' do
+    let(:actual_options) { regexp_node.options }
+    # rubocop:disable Security/Eval
+    let(:expected_options) { eval(source).options }
+    # rubocop:enable Security/Eval
+
+    context 'with an empty regexp' do
+      let(:source) { '//' }
+
+      it { expect(actual_options).to eq(expected_options) }
+    end
+
+    context 'with a regexp without option' do
+      let(:source) { '/.+/' }
+
+      it { expect(actual_options).to eq(expected_options) }
+    end
+
+    context 'with a regexp with single option' do
+      let(:source) { '/.+/i' }
+
+      it { expect(actual_options).to eq(expected_options) }
+    end
+
+    context 'with a regexp with multiple options' do
+      let(:source) { '/.+/ix' }
+
+      it { expect(actual_options).to eq(expected_options) }
+    end
+
+    context 'with a regexp with "o" option' do
+      let(:source) { '/.+/o' }
+
+      it { expect(actual_options).to eq(expected_options) }
+    end
+  end
+
   describe '#content' do
     let(:content) { regexp_node.content }