How do I use double and message chain in ruby rspec - ruby

Question

I am working on Plain Ruby Project(Non Rails Environment). However, I am getting an error,
#<Double "pr"> received unexpected message :client with (no args)
This error is returned from the double object with label pr.
Here's my rspec, I have configured the Sinatra as a fake github server and its returning a JSON response.
I have verifed the result and its returning a JSON response.
RSpec.describe Humdrum::DefaultVerifications::CodeReviewsSignedOff do
describe '.Code Reviews Signed Off' do
let(:org){
'octocat'
}
let(:number){
123
}
before do
uri = URI('https://api.github.com/repos/octocat/hello-world/pulls/42/reviews')
result=JSON.load(Net::HTTP.get(uri))
github=double
allow(github)
.to receive_message_chain(:client,:pull_request_reviews)
.with(:org,:number)
.and_return (result)
end
it 'should check pull request review response' do
object=Humdrum::DefaultVerifications::CodeReviewsSignedOff.new
github=double("pr")
expert(object.pull_request_reviews_response(github)). to eq(1)
end
end
end
As you can see in the function pull_request_reviews_response, I want to stub the github.client.pull_request_reviews, hence, in the rspec for this file,
I wrote allow, message chain and from there it returns json response.
That json response will be proccessed inside the same function and return a integer response
module Humdrum
module DefaultVerifications
class CodeReviewsSignedOff
def pull_request_reviews_response(github)
#Counting total number of user who have approved the pull request
approveCount=0
github.client.pull_request_reviews("#{github.organization}/#{github.repository}", github.number).each do |review|
username = review[:user][:login]
state = review[:state]
if state == "APPROVED" and !##approvedUser.include?(username)
##approvedUser.add(username)
puts "Changes #{state} by #{username}"
approveCount += 1
end
end
return approveCount
end
What am I doing wrong?

Answer 1

What am I doing wrong?
You have defined github as a local variable, in two different places:
before
# ...
github = double # <----- HERE
allow(github)
.to receive_message_chain(:client, :pull_request_reviews)
.with(:org, :number)
.and_return(result)
end
it 'should check pull request review response' do
# ...
github = double("pr") # <-- AND ALSO HERE
expert(object.pull_request_reviews_response(github)).to eq(1)
end
So the object you send to the method doesn't have any stubs. Hence the error message.
There are various ways you could choose to structure this test (for instance, we could talk about how using double is generally a bad idea, and so is using receive_message_chain !... I'd opt to at least use instance_double, or potentially even just pass a real object here.).
But as a minimal change, here's a way you could define the github variable once, and reference the same object in the before block and the spec itself:
let(:github) { double("pr") } # <---- !!!
before
# ...
allow(github)
.to receive_message_chain(:client, :pull_request_reviews)
.with(:org, :number)
.and_return(result)
end
it 'should check pull request review response' do
# ...
expert(object.pull_request_reviews_response(github)).to eq(1)
end