Note on exposing a required module to test it.

exposed-module-to-mock.md

I ran into some trouble writing jasmine unit tests for request.pipe today.

Exposing the request module instead of modifying require or stubbing request was easiest:

# actions.coffee
request = require 'request'

module.exports = 
  feed: (request, response) ->
    request.get("http://www.joyent.com/blog/feed").pipe res

  # Export request module so we can test piping
  _request: request

# actions_spec.coffee
actions = require "./actions"

describe 'When I request the feed', ->

  beforeEach ->
    @req = 'request'
    @res = 'response'

    @pipe = jasmine.createSpy('pipe').andReturn @res

    spyOn(actions._request, 'get').andReturn(
      pipe: @pipe
    )

  it 'should pipe feed data', ->
    actions.feed @req, @res

    url = 'http://www.joyent.com/blog/feed'

    expect(actions._request.get).toHaveBeenCalledWith url
    expect(@pipe).toHaveBeenCalledWith @res

This does unnecessarily tie the behavior of fetching and forwarding a feed to an implementation using the request module.

I looked into testing only the behavior with nock, but only read the project readme. It looks like nock does support piping.

Google is my friend.