From 65cb09bb72e8402b42b809513d3a490818f2e9bc Mon Sep 17 00:00:00 2001
From: Koichi ITO <koic.ito@gmail.com>
Date: Fri, 21 Oct 2022 15:43:48 +0900
Subject: [PATCH] Add `character_literal?` to `StrNode`

This PR adds `character_literal?` to `StrNode`.

`...begin.is?('?')` used in https://github.com/rubocop/rubocop/pull/11095
and `Style/CharacterLiteral` can be rewritten by `node.character_literal?`.
---
 .../new_add_character_literal_to_str_node.md  |  1 +
 lib/rubocop/ast/node/str_node.rb              |  4 +++
 spec/rubocop/ast/str_node_spec.rb             | 27 +++++++++++++++++++
 3 files changed, 32 insertions(+)
 create mode 100644 changelog/new_add_character_literal_to_str_node.md

diff --git a/changelog/new_add_character_literal_to_str_node.md b/changelog/new_add_character_literal_to_str_node.md
new file mode 100644
index 000000000..bf8164e6b
--- /dev/null
+++ b/changelog/new_add_character_literal_to_str_node.md
@@ -0,0 +1 @@
+* [#242](https://github.com/rubocop/rubocop-ast/pull/242): Add `character_literal?` to `StrNode`. ([@koic][])
diff --git a/lib/rubocop/ast/node/str_node.rb b/lib/rubocop/ast/node/str_node.rb
index 37b95bd73..13ee2b2c4 100644
--- a/lib/rubocop/ast/node/str_node.rb
+++ b/lib/rubocop/ast/node/str_node.rb
@@ -8,6 +8,10 @@ module AST
     class StrNode < Node
       include BasicLiteralNode
 
+      def character_literal?
+        loc.respond_to?(:begin) && loc.begin && loc.begin.is?('?')
+      end
+
       def heredoc?
         loc.is_a?(Parser::Source::Map::Heredoc)
       end
diff --git a/spec/rubocop/ast/str_node_spec.rb b/spec/rubocop/ast/str_node_spec.rb
index 4a1f6e6b5..9be2ff23a 100644
--- a/spec/rubocop/ast/str_node_spec.rb
+++ b/spec/rubocop/ast/str_node_spec.rb
@@ -30,6 +30,33 @@
     end
   end
 
+  describe '#character_literal?' do
+    context 'with a character literal' do
+      let(:source) { '?\n' }
+
+      it { is_expected.to be_character_literal }
+    end
+
+    context 'with a normal string literal' do
+      let(:source) { '"\n"' }
+
+      it { is_expected.not_to be_character_literal }
+    end
+
+    context 'with a heredoc' do
+      let(:source) do
+        <<~RUBY
+          <<-CODE
+            foo
+            bar
+          CODE
+        RUBY
+      end
+
+      it { is_expected.not_to be_character_literal }
+    end
+  end
+
   describe '#heredoc?' do
     context 'with a normal string' do
       let(:source) { "'foo'" }