rspec: How to stub an instance method called by constructor?

Here's the commit which adds the feature to rspec - This was on May 25 2008. With this you can do

A.any_instance.stub(do_something: 23)

However, the latest gem version of rspec (1.1.11, October 2008) doesn't have this patch in it.

This ticket states that they yanked it out for maintenance reasons, and an alternative solution hasn't yet been provided.

Doesn't look like you can do it at this point. You'll have to hack the class manually using alias_method or somesuch.

I've found this solution on http://pivotallabs.com/introducing-rr/

new_method = A.method(:new)A.stub!(:new).and_return do |*args|  a = new_method.call(*args)  a.should_receive(:do_something).and_return(23)  aend

I don't know how to do that in spec's mock framework, but you can easily swap it out for mocha to do the following:

# should probably be in spec/spec_helper.rbSpec::Runner.configure do |config|  config.mock_with :mochaenddescribe A, " when initialized" do  it "should set x to 42" do    A.new.x.should == 42  endenddescribe A, " when do_something is mocked" do  it "should set x to 23" do    A.any_instance.expects(:do_something).returns(23)    A.new.x.should == 23  endend