Add ragexp_dot? method to RuboCop::AST::Token.

changelog/new_add_regexp_dot_p_to_token.md

@@ -0,0 +1 @@
+* [#235](https://github.com/rubocop-hq/rubocop-ast/pull/235): Add `regexp_dot?` method to `RuboCop::AST::Token`. ([@koic][])

lib/rubocop/ast/token.rb

@@ -100,6 +100,10 @@ def comma?
         type == :tCOMMA
       end
 
+      def regexp_dot?
+        %i[tDOT2 tDOT3].include?(type)
+      end
+
       def rescue_modifier?
         type == :kRESCUE_MOD
       end

spec/rubocop/ast/token_spec.rb

@@ -8,6 +8,8 @@
     def some_method
       [ 1, 2 ];
       foo[0] = 3
+      1..42
+      1...42
     end
   RUBY
 
@@ -22,6 +24,8 @@ def some_method
     processed_source.find_token { |t| t.text == '[' && t.line == 3 }
   end
   let(:comma_token) { processed_source.find_token { |t| t.text == ',' } }
+  let(:irange_token) { processed_source.find_token { |t| t.text == '..' } }
+  let(:erange_token) { processed_source.find_token { |t| t.text == '...' } }
   let(:right_array_bracket_token) do
     processed_source.find_token { |t| t.text == ']' && t.line == 3 }
   end
@@ -69,7 +73,7 @@ def some_method
     it 'returns line of token' do
       expect(first_token.line).to eq 1
       expect(zero_token.line).to eq 4
-      expect(end_token.line).to eq 5
+      expect(end_token.line).to eq 7
     end
   end
 
@@ -85,15 +89,15 @@ def some_method
     it 'returns index of first char in token range of entire source' do
       expect(first_token.begin_pos).to eq 0
       expect(zero_token.begin_pos).to eq 44
-      expect(end_token.begin_pos).to eq 51
+      expect(end_token.begin_pos).to eq 68
     end
   end
 
   describe '#end_pos' do
     it 'returns index of last char in token range of entire source' do
       expect(first_token.end_pos).to eq 9
       expect(zero_token.end_pos).to eq 45
-      expect(end_token.end_pos).to eq 54
+      expect(end_token.end_pos).to eq 71
     end
   end
 
@@ -232,6 +236,18 @@ def some_method
       end
     end
 
+    describe '#regexp_dot?' do
+      it 'returns true for regexp tokens' do
+        expect(irange_token).to be_regexp_dot
+        expect(erange_token).to be_regexp_dot
+      end
+
+      it 'returns false for non comma tokens' do
+        expect(semicolon_token).not_to be_regexp_dot
+        expect(right_ref_bracket_token).not_to be_regexp_dot
+      end
+    end
+
     describe '#rescue_modifier?' do
       let(:source) { <<~RUBY }
         def foo