Add --type and --method-type option to rbs parse

lib/rbs/cli.rb

@@ -904,7 +904,9 @@ def run_vendor(args, options)
     end
 
     def run_parse(args, options)
+      parse_method = :parse_signature
       e_code = nil
+
       OptionParser.new do |opts|
         opts.banner = <<-EOB
 Usage: rbs parse [files...]
@@ -919,6 +921,8 @@ def run_parse(args, options)
         EOB
 
         opts.on('-e CODE', 'One line RBS script to parse') { |e| e_code = e }
+        opts.on('--type', 'Parse code as a type') { |e| parse_method = :parse_type }
+        opts.on('--method-type', 'Parse code as a method type') { |e| parse_method = :parse_method_type }
       end.parse!(args)
 
       loader = options.loader()
@@ -934,7 +938,7 @@ def run_parse(args, options)
 
       bufs.each do |buf|
         RBS.logger.info "Parsing #{buf.name}..."
-        Parser.parse_signature(buf)
+        Parser.public_send(parse_method, buf)
       rescue RBS::ParsingError => ex
         stdout.puts ex.message
         syntax_error = true

test/rbs/cli_test.rb

@@ -415,6 +415,30 @@ def test_parse_e
     end
   end
 
+  def test_parse_type
+    with_cli do |cli|
+      cli.run(['parse', '--type', '-e', 'bool'])
+      assert_empty stdout.string
+
+      assert_raises(SystemExit) { cli.run(['parse', '--type', '-e', '?']) }
+      assert_equal [
+        "-e:1:0...1:1: Syntax error: unexpected token for simple type, token=`?` (pQUESTION)",
+      ], stdout.string.split("\n").sort
+    end
+  end
+
+  def test_parse_method_type
+    with_cli do |cli|
+      cli.run(['parse', '--method-type', '-e', '() -> void'])
+      assert_empty stdout.string
+
+      assert_raises(SystemExit) { cli.run(['parse', '--method-type', '-e', '()']) }
+      assert_equal [
+        "-e:1:2...1:3: Syntax error: expected a token `pARROW`, token=`` (pEOF)",
+      ], stdout.string.split("\n").sort
+    end
+  end
+
   def test_prototype_no_parser
     Dir.mktmpdir do |dir|
       with_cli do |cli|