The ultimate rspec cheatsheet for testing Rails APIs

Test coverage

To check your test coverage, use simplecov .
Add it to your gemfile then run bundle install

gem 'simplecov', require: false, group: :test

At the very top of your spec/spec_helper.rb file, add

require 'simplecov'
SimpleCov.start

Run bundle exec rspec as usual to see test coverage.

Setup

At the top of each test file, add

require ‘rails_helper`

Test models

Describe a model test. For example, a user model

RSpec.describe User, type: :model do
  describe '# when created user is valid' do
  end
end

Create a model instance example

let(:user) { User.create(name: 'test_user', email: 'test@test.com', password: 'password', password_confirmation: 'password') }

Create an it block for each test.

it 'checks for the presence of values in required fields' do
      expect(user.name).to eq('test_user')
end

using the expect + eq matcher inside an it block

expect(user.password).to eq(‘password’)

using the to_not + be valid matcher

expect(user).to_not be_valid

using the to + be valid

expect(user).to be_valid

Request specs

Describe a test block

RSpec.describe 'Users', type: :request do
end

Create an it block

it 'tests that an authenticated user can create comments' do
end

Within an it block, create params and necessary headers. E.g

params = { name: 'test_user', email: 'test@test.com', password: 'password', password_confirmation: 'password' }
headers = { ‘Accept’: ‘application/json’, ‘Content-Type’: ‘application/json’ }

Make a request with the params and headers. For example, a POST request

post '/api/v1/users', params: params.to_json, headers: headers

Get the response from the request and save to a variable

user = JSON.parse(response.body)

Add an authorization header to a request

headers = { ‘Accept’: ‘application/json’, ‘Content-Type’: ‘application/json’, ‘Authorization’: “Bearer #{user[‘token’]}” }

Putting it all together

it 'tests that an authenticated user can create comments' do
      # create a user
      params = { name: 'test_user', email: 'test@test.com', password: 'password', password_confirmation: 'password' }
      headers = { 'Accept': 'application/json', 'Content-Type': 'application/json' }
      post '/api/v1/users', params: params.to_json, headers: headers
      user = JSON.parse(response.body)
# create a ticket
      ticket_params = { user_id: user['user']['user_id'], title: 'test ticket', request: 'this is a test request' }
      headers = { 'Accept': 'application/json', 'Content-Type': 'application/json', 'Authorization': "Bearer #{user['token']}" }
      post '/api/v1/tickets', params: ticket_params.to_json, headers: headers
      tickets = JSON.parse(response.body)
end

Request matchers

.to have_http_status

expect(response).to have_http_status(401)

.to include

expect(response.body).to include('not authorized')

length

expect(tickets['tickets'].length).to eq(2)