safe-me

Description:

Add typechecking whenever you need it, without messing up your class files.

Install

sudo gem install safe-me

Usage

require 'safe-me'

If you don’t use safe-me with rails you have to manually call

SafeMe.init

The declaration files have to be put in a folder called ‘safe’ in the app’s root. The naming convention for those files is ‘class_name_safe.rb’. SafeMe automatically loads and evaluates those files on the call of SafeMe.init.

DSL

The DSL ist very simple. Let me explain on an example:

#safe Class tells SafeMe which class it should work on
#be sure to have the class in scope
safe Foo do

  #for_method takes the name of the method to be made safe
  #as symbol
  for_method :a_method do

    #for each argument the method takes, you have to call argument
    #with the type as parameter
    argument Integer
  end  
end

For now there are 4 kinds of possible argument types.

  • Classes

You can simply pass a class as type to the argument call. There are some special cases:

VarArgs: if you have a method with varargs, you have to have to pass VarArgs.ofType(Class) as the type Array: if you want type safe arrays, you can pass Array.ofType(Class) Hash: for hashes you can pass Hash.ofType(Class, Class) where the first class is for the key and the second for the value

  • Nilable

If you also want to be able to pass nil to a method, if the argument is optional for example, you can pass nilable(Class) as type

  • RespondsTo

If you only want to be sure, that an argument responds to some methods you can pass responds_to(*methods) where *methods should be the method names as symbols

  • QuacksLike

If you need the same responds_to on multiple methods it can be useful to create a clean room class, that contains those methods and call quacks_like(Class) instead. quacks_like ensures, that every public instance method of this class is also available on the object, that gets passed to the method

License:

The MIT License

Copyright © 2010 Dario Rexin

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.