Ruby metaprogramming is worth noting.

Ruby metaprogramming is worth noting.

Avoid infinite loop metaprogramming.

Do not confuse the core class (do not use monkey patch) when writing a function library ).

It is best to use the code block form in the string interpolation form.
When you use string interpolation, _ FILE _ and _ LINE __are always provided to make your backtracking meaningful.

 class_eval 'def use_relative_model_naming?; true; end', __FILE__, __LINE__

Define_method is best to use class_eval {def ...}

When class_eval (or other eval) and string interpolation are used, add a comment block to display it during insertion (this is my practice in rails code ):

 # from activesupport/lib/active_support/core_ext/string/output_safety.rb UNSAFE_STRING_METHODS.each do |unsafe_method|  if 'String'.respond_to?(unsafe_method)  class_eval <<-EOT, __FILE__, __LINE__ + 1   def #{unsafe_method}(*args, &block)  # def capitalize(*args, &block)   to_str.#{unsafe_method}(*args, &block) # to_str.capitalize(*args, &block)   end          # end   def #{unsafe_method}!(*args)    # def capitalize!(*args)   @dirty = true       # @dirty = true   super         # super   end          # end  EOT  end end

Avoid using method_missing in metaprogramming, which makes tracing very troublesome. This habit is not listed in # methods. misspelling methods may also work silently, such as nukes. launch_state = false. Use the delegate, proxy, or define_method. If so, use method_missing,
Make sure respond_to_missing is also defined?
Just capture the first-defined method, such as find_by _ *-the better your code (assertive.
At the end of the statement, super is called.
Delegate to a definite, non-magic method:

 # bad def method_missing?(meth, *args, &block)  if /^find_by_(?<prop>.*)/ =~ meth  # ... lots of code to do a find_by  else  super  end end # good def method_missing?(meth, *args, &block)  if /^find_by_(?<prop>.*)/ =~ meth  find_by(prop, *args, &block)  else  super  end end # best of all, though, would to define_method as each findable attribute is declared