From: brabuhr@...
Date: 2008-11-07T00:30:48+09:00
Subject: Re: Redefine while

On Thu, Nov 6, 2008 at 10:00 AM, Emil Sandin <esandin@gmail.com> wrote:
> Hi, is there an easy way to redefine 'while'. I have a class that uses a
> while loop. In my unit test it always evaluates to false (which is
> correct). I only want the loop to run once, and the enter. Just like an
> if.

As others already noted, while is a keyword not a method.  But
depending on how your code is structured you might be able to mock the
condition in your test:

$ cat foo.rb
class Foo
  attr_reader :i

  def initialize
    @i = 0
  end

  def condition
    @i < 10
  end

  def method
    while condition
      @i += 1
    end
  end
end

$ cat foo_spec.rb
require 'foo'

describe Foo do
  it "should loop once" do
    f = Foo.new
    f.i.should == 0
    f.method
    f.i.should == 10
  end

  it "should loop once" do
    f = Foo.new
    f.should_receive(:condition).and_return(true, false)
    f.i.should == 0
    f.method
    f.i.should == 1
  end
end

$ spec foo_spec.rb
..
Finished in 0.008461 seconds
2 examples, 0 failures