如何在ruby rsspec中使用double和消息链

Question

我正在开发Plain Ruby项目(非Rails环境(。然而，我得到了一个错误，

#<Double "pr"> received unexpected message :client with (no args)

此错误是从标签为pr的double对象返回的。这是我的rspec，我已经将Sinatra配置为假github服务器，并返回JSON响应。我已经验证了结果及其返回的JSON响应。

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

正如您在函数pull_request_reviews_response中所看到的，我想将github.client.pull_request_reviews截尾，因此，在该文件的rspec中，我写了allow，消息链，从那里它返回json响应。json响应将在同一函数中进行处理，并返回一个整数响应

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

我做错了什么？

Answer 1

我做错了什么？

您已经在两个不同的地方将github定义为局部变量：

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

因此，您发送给该方法的对象没有任何存根。因此出现了错误消息。

你可以选择多种方式来构建这个测试(例如，我们可以讨论使用double通常是个坏主意，使用receive_message_chain也是如此！……我会选择至少使用instance_double，甚至可能只是在这里传递一个真实的对象。(

但作为一个最小的更改，这里有一种方法可以定义github变量一次，并在before块和规范本身中引用相同的对象：

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