diff --git a/app/lib/rack/baseup.rb b/app/lib/rack/baseup.rb
index cb86b70..d42023a 100644
--- a/app/lib/rack/baseup.rb
+++ b/app/lib/rack/baseup.rb
@@ -11,17 +11,11 @@ class BaseUp
     # @param [Rack::Request] req
     # @return [String]
     def request_info(req)
-      arr = []
-      arr << request_line(req)
-      arr += request_headers(req)
-
-      body = request_body(req)
-      unless body.empty?
-        arr << ""
-        arr << body
-      end
-
-      arr.join("\n")
+      [
+        request_line(req),
+        request_headers(req),
+        request_body(req) || ""
+      ].join("\n")
     end
 
     # Returns Base64 encoded HTTP request information
diff --git a/app/main.rb b/app/main.rb
index c676113..18adccf 100644
--- a/app/main.rb
+++ b/app/main.rb
@@ -16,7 +16,7 @@ def call(_)
     #
     # @return [Array<String>]
     def defaults
-      Dir.glob(File.expand_path("defaults/**/*.yml", __dir__))
+      @defaults ||= Dir.glob(File.expand_path("defaults/**/*.yml", __dir__))
     end
   end
 end
diff --git a/app/mrr.rb b/app/mrr.rb
index f91967f..4ce9e64 100644
--- a/app/mrr.rb
+++ b/app/mrr.rb
@@ -82,11 +82,7 @@ def response
     def valid?
       return false unless attributes.is_a? Hash
 
-      begin
-        meta? && trigger? && response?
-      rescue NoMethodError
-        false
-      end
+      respond_to?(:meta?) && respond_to?(:trigger?) && respond_to?(:response?)
     end
 
     def response?