Mock AmpersandJS sync for tests (Mocha & Sinon)

ampersand-mock-sync.js

import BaseModel from 'ampersand-model'
import BaseCollection from 'ampersand-collection'
import sync from 'ampersand-sync'

const xhrImplementation = xhrOptions => {
  xhrOptions.success && xhrOptions.success.call(null, {})
  return {}
}

BaseModel.prototype.sync = BaseCollection.prototype.sync = (method, model, options = {}) => {
  options.xhrImplementation = options.xhrImplementation || xhrImplementation
  sync.call(null, method, model, options)
}

ampersand-mock-xhr.js

import cloneDeep from 'lodash.clonedeep'
import { stub } from 'sinon'

/**
 * Mock AJAX requests by passing a custom xhr implementation to Model/Collection.sync()
 *
 * @param   {Object} modelOrCollection Ampersand Model/Collection
 * @param   {Object} data              Mock data object for success/error response
 * @returns {Object}                   Sinon stub
 *
 */
export default function mockXhr (modelOrCollection, data = {}) {

  const sync = modelOrCollection.sync

  return stub(modelOrCollection, 'sync', (method, model, options = {}) => {

    options.xhrImplementation = xhrOptions => {
      const xhrCallback = data.error ? xhrOptions.error : xhrOptions.success
      xhrCallback.call(null, cloneDeep(data.error) || cloneDeep(data.success) || {})
      return {}
    }

    sync.call(this, method, model, options)

  })

}

ampersand-mock-xhr.sh

   mocha --compilers js:babel-core/register ./ampersand-mock-sync *.spec.js

xhr.spec.js

import BaseModel from 'ampersand-model'
import BaseCollection from 'ampersand-collection'
import mockXhr from './ampersand-mock-xhr'

const Model = BaseModel.extend({
  url: 'http://localhost/foo'
})

const Collection = BaseCollection.extend({
  model: Model
})

let collection, stubCollection

before(() => {
  collection = new Collection()
  stubCollection = mockXhr(collection, { success: [ { foo: 'bar' }, { foo: 'baz' } ] )
})

after(() => {
  stubCollection.restore()
})

it('should return a mocked response', () => {
  collection.fetch()
  setTimeout(() => {
    expect(collection).to.have.length(2)
    expect(collection.at(0).foo).to.equal('bar')
  })
})