extract FULL_TEXT_ERRORS check to Utils.full_text_errors_enabled?

Author: Romex91

lib/react_on_rails/prerender_error.rb

@@ -57,7 +57,7 @@ def calc_message(component_name, console_messages, err, js_code, props)
 
         MSG
 
-        backtrace = if ENV["FULL_TEXT_ERRORS"] == "true"
+        backtrace = if Utils.full_text_errors_enabled?
                       err.backtrace.join("\n")
                     else
                       "#{err.backtrace.first(15).join("\n")}\n" +

lib/react_on_rails/utils.rb

@@ -185,10 +185,14 @@ def self.react_on_rails_pro_version
                                     end
     end
 
+    def self.full_text_errors_enabled?
+      ENV["FULL_TEXT_ERRORS"] == "true"
+    end
+
     def self.smart_trim(str, max_length = 1000)
       # From https://stackoverflow.com/a/831583/1009332
       str = str.to_s
-      return str if ENV["FULL_TEXT_ERRORS"] == "true"
+      return str if full_text_errors_enabled?
       return str unless str.present? && max_length >= 1
       return str if str.length <= max_length