Unable to generate an instance_spy for Gitlab::Client

[jblackman]

Here's an interesting problem. For my project unit tests I'm doubling the Gitlab::Client. Here is a stripped-down example:

require 'gitlab'

describe 'Creating an instance_spy on the client' do
  let(:gitlab_client) { instance_spy ::Gitlab::Client, get_file: 'foo' }

  before :each do
    allow(::Gitlab).to receive(:client).and_return(gitlab_client)
  end

  it 'ought to work' do
    client = Gitlab.client(endpoint: 'foo')
  end
end

This fails in an interesting manner:

Creating an instance_spy on the client
  ought to work (FAILED - 1)

Failures:

  1) Creating an instance_spy on the client ought to work
     Failure/Error: raise Error::MissingCredentials.new("Please set an endpoint to API") unless @endpoint

     Gitlab::Error::MissingCredentials:
       Please set an endpoint to API
     # ./lib/gitlab/request.rb:90:in `set_request_defaults'
     # ./lib/gitlab/api.rb:16:in `initialize'
     # ./lib/gitlab.rb:18:in `new'
     # ./lib/gitlab.rb:18:in `client'
     # ./lib/gitlab.rb:23:in `method_missing'
     # ./spy_spec.rb:4:in `block (2 levels) in <top (required)>'
     # ./spy_spec.rb:7:in `block (2 levels) in <top (required)>'

Finished in 0.00164 seconds (files took 0.17132 seconds to load)
1 example, 1 failure

Failed examples:

rspec ./spy_spec.rb:10 # Creating an instance_spy on the client ought to work

Looking into the source (I've tried this against both release 3.6.1 and master), I think I know what the problem is: in order for rspec to validate the stubbed method, it must first see if the class responds to the method. At that point, it hits either Gitlab.respond_to? or Gitlab.respond_to_missing?, depending on the gem version. This create a client object with no options, which fails because endpoint is not specified.

I want to stub the client, but in doing so it creates the client. Catch22!

Anyway, if I stub the method that does the validation, I get past this problem, but it seems like a bit of a hack to have to work around it like that (and not intuitive to the next person who comes along):

require 'gitlab'

describe 'Creating an instance_spy on the client' do
  let(:gitlab_client) { instance_spy ::Gitlab::Client, get_file: 'foo' }

  before :each do
    allow_any_instance_of(::Gitlab::Client).to receive(:set_request_defaults).and_return(nil)
    allow(::Gitlab).to receive(:client).and_return(gitlab_client)
  end

  it 'runs very nicely, thank you' do
    client = Gitlab.client(endpoint: 'foo')
    expect(client.get_file('a','b','c')).to eq 'foo'
  end
end

Any ideas? Should I be doing this a different way?

[asedge]

Sorry man, I looked a this a while back but could not figure out a different way.