RSpec how to stub out yield and have it not hit ensure - ruby

Question

I have an around action_action called set_current_user
def set_current_user
CurrentUser.set(current_user) do
yield
end
end
In the CurrentUser singleton
def set(user)
self.user = user
yield
ensure
self.user = nil
end
I cannot figure out how to stub out the yield and the not have the ensure part of the method called
Ideally I would like to do something like
it 'sets the user' do
subject.set(user)
expect(subject.user).to eql user
end
Two errors I am getting
No block is given
When I do pass a block self.user = nil gets called
Thanks in advance

Answer 1

A few things to point out that might help:
ensure is reserved for block of codes that you want to run no matter what happens, hence the reason why your self.user will always be nil. I think what you want is to assign user to nil if there's an exception. In this case, you should be using rescue instead.
def set(user)
self.user = user
yield
rescue => e
self.user = nil
end
As for the unit test, what you want is to be testing only the .set method in the CurrentUser class. Assuming you have everything hooked up correctly in your around filter, here's a sample that might work for you:
describe CurrentUser do
describe '.set' do
let(:current_user) { create(:user) }
subject do
CurrentUser.set(current_user) {}
end
it 'sets the user' do
subject
expect(CurrentUser.user).to eq(current_user)
end
end
end
Hope this helps!

Answer 2

I am not sure what you intend to accomplish with this as it appears you just want to make sure that user is set in the block and unset afterwards. If this is the case then the following should work fine
class CurrentUser
attr_accessor :user
def set(user)
self.user = user
yield
ensure
self.user = nil
end
end
describe '.set' do
subject { CurrentUser.new }
let(:user) { OpenStruct.new(id: 1) }
it 'sets user for the block only' do
subject.set(user) do
expect(subject.user).to eq(user)
end
expect(subject.user).to be_nil
end
end
This will check that inside the block (where yield is called) that subject.user is equal to user and that afterwards subject.user is nil.
Output:
.set
sets user for the block only
Finished in 0.03504 seconds (files took 0.14009 seconds to load)
1 example, 0 failures

Answer 3

I failed to mention I need to clear out the user after every request.
This is what I came up with. Its kinda crazy to put the expectation inside of the lambda but does ensure the user is set prior to the request being processed and clears it after
describe '.set' do
subject { described_class }
let(:user) { OpenStruct.new(id: 1) }
let(:user_expectation) { lambda{ expect(subject.user).to eql user } }
it 'sets the user prior to the block being processed' do
subject.set(user) { user_expectation.call }
end
context 'after the block has been processed' do
# This makes sure the user is always cleared after a request
# even if there is an error and sidekiq will never have access to it.
before do
subject.set(user) { lambda{} }
end
it 'clears out the user' do
expect(subject.user).to eql nil
end
end
end