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Write stub to rspec?

I need to maintain a Ruby script that requires some libraries that I don't have locally and that won't work in my environment. However, I want to specify some methods in this script so that I can change them easily.

Is there a way to stub out some of the statements require

in the script that I want to test so that it can be rspec loaded and the spec can be executed in my environment?

Example ( old_script.rb

):

require "incompatible_lib"
class Script
  def some_other_stuff
    ...
  end
  def add(a,b)
    a+b
  end
end

How can I write a test to test a function add

without splitting the old_Script.rb file and without giving incompatible_lib

me one?

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2 answers


Thanks, I also thought about adding files, but finally hacked the request itself in the test case:

module Kernel
  alias :old_require :require
  def require(path)
    old_require(path) unless LIBS_TO_SKIP.include?(path)
  end
end


I know this is an ugly hack, but since this is legacy code executed on a modified ruby ​​compiler, I cannot easily run these libraries, and this is enough to let me check my modifications ...

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Instead of stubbing require

, which is "inherited" from Kernel

, you can do this:

  • Create a dummy file incompatible_lib.rb

    somewhere that is not in your $ LOAD_PATH. If it's a Ruby (not Rails) application, don't put it in lib/

    and spec/

    .
  • You can do this in a number of ways, but I will tell you one method: in your spec file that checks Script

    , change $ LOAD_PATH to include the parent directory of your dummy t22>.
  • The order is very important - in the future you will include script.rb

    (the file that defines Script

    ).


This will cause a problem and allow you to test the method add

.

Once you've successfully tested it Script

, I highly recommend refactoring it so that you don't have to do this technique, which is a hack, IMHO.

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