Rspec check return value

Question

I'm learning test in rails rspec. I have this part of test:

subject(:service) { described_class.new() }
context 'when sth' do
  it 'should sth' do
    expect ( service.call(@params) ).to eq(0)
  end
end

Service's method call return number. But I get something like this:

Failures:

 1) Module::Registration when sth should sth
 Failure/Error: expect ( service.call(@params) ).to eq(2)
 NoMethodError:
   undefined method `to' for 2:Fixnum
 # ./spec/module/registration_spec.rb:22:in `block (3 levels) in <module:Module>'

Finished in 2.48 seconds
1 example, 1 failure

So how can I check that method return correct "Number" variable using to?

Answer 1

You have to remove the space between expect and (:

expect( service.call(@params) ).to eq(0)
#    ^^

Otherwise Ruby evaluates the expression separately:

( service.call(@params) ).to
( 2 ).to
#=> undefined method `to' for 2:Fixnum