Testing mixin in ruby - ruby-on-rails

Question

I'm trying to write a rspec test for a mixin class. I have the following.
module one
module two
def method
method_details = super
if method_details.a && method_details.b
something
elsif method_details.b
another thing
else
last thing
end
end
end
end
Now I have mocked the "method" object that will be passed to the class.
But I'm struggling to access the super method.
I did,
let(:dummy_class) { Class.new { include one::two } }
How to pass the mocked method object to this dummy class?
How do I go about testing this? New to ruby, can someone show me a direction with this.
Thanks in advance.
UPDATE:
I tried,
let(:dummy_class) {
Class.new { |d|
include one::two
d.method = method_details
}
}
let (:method_details){
'different attributes'
}
still doesn't work. I get undefined local variable or method method_details for #<Class:0x007fc9a49cee18>

Answer 1

I personally test mixing with the class. Because the mixing (module) itself has no meaning unless its attached to a class/object.
Ex:
module SayName
def say_name
p 'say name'
end
end
class User
include SayName
end
So I believe you should test your module with attached to the relevant class / object.
How ever this is a different perspective on testing mixings
HTH

Answer 2

I think that in your specs, you'll need to explicitly provide a super class definition for when super is called in #method as "you can't mock super and you shouldn't".
I've attempted to spec out all three of your scenarios with the following minor changes:
Changed your example code slightly to become valid Ruby
Changed #method to #the_method so it doesn't conflict with Object#method
Used OpenStruct to represent the object that super returns, because all I know is that it's an object that has methods #a and #b. You can change that out as appropriate for your real specs
Copy and paste the class and specs below into a file and give them a try:
module One
module Two
def the_method
method_details = super
if method_details.a && method_details.b
'something'
elsif method_details.b
'another thing'
else
'last thing'
end
end
end
end
RSpec.describe One::Two do
require 'ostruct'
let(:one_twoable) { Class.new(super_class) { include One::Two }.new }
describe '#the_method' do
let(:the_method) { one_twoable.the_method }
context 'when method_details#a && method_details#b' do
let(:super_class) do
Class.new do
def the_method
OpenStruct.new(a: true, b: true)
end
end
end
it 'is "something"' do
expect(the_method).to eq('something')
end
end
context 'when just method#b' do
let(:super_class) do
Class.new do
def the_method
OpenStruct.new(a: false, b: true)
end
end
end
it 'is "another thing"' do
expect(the_method).to eq('another thing')
end
end
context 'when neither of the above' do
let(:super_class) do
Class.new do
def the_method
OpenStruct.new(a: false, b: false)
end
end
end
it 'is "last thing"' do
expect(the_method).to eq('last thing')
end
end
end
end