Define method using class_eval instead of define_method.

AZQ1994 · AZQ1994 · commit 5c747d0c0a00 · 2026-01-28T17:51:04.000+09:00
diff --git a/lib/simple_json/simple_json_renderer.rb b/lib/simple_json/simple_json_renderer.rb
@@ -39,9 +39,7 @@ def load_template_from_file(template_path)
         SimpleJson.template_paths.each do |path|
           file_path = Rails.root.join("#{path}/#{template_path}.simple_json.rb").to_path
 
-          if File.exist?(file_path)
-            return define_template_method(template_path, file_path)
-          end
+          return define_template_method(template_path, file_path) if File.exist?(file_path)
         end
 
         nil
@@ -52,9 +50,7 @@ def define_template_method(template_path, file_path)
         @template_num += 1
         method_name = :"template_#{@template_num}"
         render_methods[template_path] = method_name
-        define_method(method_name, &SimpleJsonTemplate.new(file_path).lambda)
-
-        return method_name
+        SimpleJsonTemplate.new(file_path).define_to_class(self, method_name)
       end
 
       def render_methods
diff --git a/lib/simple_json/simple_json_template.rb b/lib/simple_json/simple_json_template.rb
@@ -7,20 +7,45 @@ def initialize(path)
       @source = File.read(path)
     end
 
-    def lambda
-      @lambda ||= eval(code, TOPLEVEL_BINDING, @path) # rubocop:disable Security/Eval
+    def define_to_class(klass, method_name)
+      method_string = to_method_string(method_name)
+      klass.class_eval(method_string, @path)
+
+      method_name
     end
 
+    private
+
     def code
       @code ||= lambda_stringify(@source)
     end
 
-    private
-
     def lambda_stringify(source)
       return source if source.match?(/^(?:\s*(?:#.*?)?\n)*\s*->/)
 
       "-> { #{source} }"
     end
+
+    def method_string_from_lambda(source, method_name)
+      pattern = %r{
+        \A(?<prefix>(?:\s*#.*\n|\s+)*)
+        ->\s*
+        (?:\((?<params_p>.*?)\)|(?<params_n>[^{ ]*?))
+        \s*(?:\{(?<body>.*)\}|do(?<body>.*)end)
+        (?<suffix>(?:\s*#.*|\s+)*)\z
+      }mx
+
+      match = source.match(pattern)
+      raise :parse_error unless match
+
+      params = (match[:params_p] || match[:params_n] || "").strip
+      arg_part = params.empty? ? "" : "(#{params})"
+
+      "#{match[:prefix]}def #{method_name}#{arg_part};#{match[:body]};end#{match[:suffix]}"
+    end
+
+    def to_method_string(method_name)
+      method_string_from_lambda(code, method_name)
+    end
   end
 end
