Minitest / Mocha嵌套存根

Question

I want to stub a function that returns another stub using Mocha on Minitest. This is the code

@instance = stub('instance') do
      stubs(:destroy).returns(true)
      stubs(:id).returns(0)
end
find_by_id = stub do 
      stubs(:find_by_id).returns(nil) #default
      stubs(:find_by_id).with(@instance.id).returns(@instance)
    end 
@user.stubs(:instances).returns(find_by_id)

When I run the code with byebug, @instance is defined:

(byebug) @instance
#<Mock:instance>

however, inside find_by_id = stub do

(byebug) @instance
nil

I read here about using mock instead of stub, but that does not work either.

I don't get why @instance is nil inside the do block , being that it was previously defined.

Answer 1

Well apparently is under investigation. source

For now, I could fix it by simply using 'instance' instead of '@instance'.