thiagoa

<!-- app/views/home/index.html.erb -->
<div data-twitter-app>
  <div data-tweets>
  </div>
</div>

thiagoa

# spec/features/twitter_timeline_spec.rb
require 'feature_helper'

RSpec.feature 'twitter timeline' do
  scenario 'a user views a twitter timeline' do
    pending

    visit root_path

    within '[data-twitter-app]' do

thiagoa

def stub_timeline(id:, returns:)
  instance = instance_double(TwitterTimelineHub)
  allow(instance).to receive(:call).with(id).once.and_return(returns)

  allow(TwitterTimelineHub).to receive(:new).once.and_return(instance)
end

def stub_result(**attrs)
  instance_double(TwitterTimelineHub::Result, **attrs)
end

thiagoa

# app/models/twitter_timeline_hub.rb
class TwitterTimelineHub
  Result = Struct.new(:tweets, :status)
  
  def call(id)
  end
end

thiagoa

require 'rails_helper'

RSpec.describe TwitterTimelineController, type: :request do
  def stub_timeline(id:, returns:)
    instance = instance_double(TwitterTimelineHub)
    allow(instance).to receive(:call).with(id).once.and_return(returns)

    allow(TwitterTimelineHub).to receive(:new).once.and_return(instance)
  end

thiagoa

result = stub_result(
  status: :ok,
  tweets: [
    ‘screen_name’ => ‘joe’,
    ‘text’ => ‘Hi @bob, I am Joe!’,
    ‘mentions’ => [‘bob’],
    ‘created_at’ => Time.new(2016, 1, 1)
  ]
)

thiagoa

twitter_timeline_hub = TwitterTimelineHub.new

# returns a struct with results, which include Tweets
result = twitter_timeline_hub.call(‘thiagoaraujos’)

thiagoa

# config/routes.rb
Rails.application.routes.draw do
  root to: 'home#index'
  resources :twitter_timeline, only: %i(show)
end

thiagoa

# app/controllers/twitter_timeline_controller.rb
class TwitterTimelineController < ApplicationController
  def show
    twitter_timeline_hub = TwitterTimelineHub.new
    result = twitter_timeline_hub.call(params[:id])

    render json: { tweets: result.tweets, status: result.status }
  end
end

thiagoa

# spec/models/twitter_client_factory_spec.rb
require 'twitter'
require 'spec_helper'
require_relative '../../app/models/twitter_client_factory'

RSpec.describe TwitterClientFactory do
  describe '#call' do
    it 'builds a twitter client class with the passed config' do
      instance = TwitterClientFactory.new.call(
        'consumer_key' => 'ck',