How can I add examples to rspec at runtime?

Question

I am trying to write a spec were the number of examples i.e. 'it "should ..." do' are determined at runtime. I tried putting the 'it' method in my own method so that I could call it multiple times:

def new_method(test)  
    it "#{test} should... " do  
    end  
end  

However, the 'it' method is not available from the current Spec::Example::ExampleGroup::Subclass instance.

Answer 1

To avoid code duplication, sometimes I do something like this:

describe SomeOjbect do
  %w(a b c d e f g).each do |val|
    it "should have a value of #{val}" do
      # ...
    end
  end
end

Which would create 7 examples in the spec. I suppose if you really were dead-set on using a method, you could do something like this:

def new_method(grp, test)
  grp.instance_eval do
    it "#{test} should..." do
      # ...
    end
  end
end

describe SomeObject do
  new_method(self, "a")
  new_method(self, "b")
  new_method(self, "c")
  new_method(self, "d")
  # ...
end

Here you pass self, which is the scope of the describe block, and instance_eval lets you execute code as if you were in that block, so the it method is available.

Answer 2

http://github.com/dchelimsky/rspec/wiki/FAQ#dynamic_specs