Add test for `ServicesController`

spec/controllers/services_controller_spec.rb

@@ -0,0 +1,41 @@
+require 'rails_helper'
+
+describe ServicesController, type: :controller do
+  context 'successful Twitter sign in' do
+    let(:user) { FactoryBot.create(:user) }
+
+    before do
+      sign_in user
+      OmniAuth.config.test_mode = true
+      OmniAuth.config.mock_auth[:twitter] = OmniAuth::AuthHash.new({
+                                                                     'provider' => 'twitter',
+                                                                     'uid' => '12',
+                                                                     'info' => { 'nickname' => 'jack' },
+                                                                     'credentials' => { 'token' => 'AAAA', 'secret' => 'BBBB' }
+                                                                   })
+      request.env["omniauth.auth"] = OmniAuth.config.mock_auth[:twitter]
+    end
+
+    after do
+      OmniAuth.config.mock_auth[:twitter] = nil
+    end
+
+    subject { get :create, params: { provider: 'twitter' } }
+
+    context 'no services connected' do
+    it 'creates a service integration' do
+      expect { subject }.to change { Service.count }.by(1)
+    end
+    end
+
+    context 'a user has a service connected' do
+      let(:other_user) { FactoryBot.create(:user) }
+      let!(:service) { Services::Twitter.create(user: other_user, uid: 12) }
+
+      it 'shows an error when trying to attach a service account which is already connected' do
+        subject
+        expect(flash[:error]).to eq("The Twitter account you are trying to connect is already connected to another #{APP_CONFIG['site_name']} account.")
+      end
+    end
+  end
+end