Skip to main content


Booster applications are fully tested by default. This means that you can be sure that your application will work as expected. However, you can also write your own tests to check that your application behaves as you expect. In this section, we will leave some recommendations on how to test your Booster application.

Testing Booster applications

To properly test a Booster application, you should create a test folder at the same level as the src one. Apart from that, tests' names should have the <my_test>.test.ts format.

When a Booster application is generated, you will have a script in a package.json like this:

"scripts": {
"test": "nyc --extension .ts mocha --forbid-only \"test/**/*.test.ts\""

The only thing that you should add to this line are the AWS_SDK_LOAD_CONFIG=true and BOOSTER_ENV=test environment variables, so the script will look like this:

"scripts": {
"test": "AWS_SDK_LOAD_CONFIG=true BOOSTER_ENV=test nyc --extension .ts mocha --forbid-only \"test/**/*.test.ts\""

Testing with sinon-chai

The BoosterConfig can be accessed through the Booster.config on any part of a Booster application. To properly mock it for your objective, we really recommend to use sinon replace method, after configuring your Booster.config as desired.

In the example below, we add 2 "empty" read-models, since we are iterating Booster.config.readModels from a command handler:

// Test
import { replace } from 'sinon'

const config = new BoosterConfig('test')
config.appName = 'testing-time'
config.providerPackage = '@boostercloud/framework-provider-aws'
config.readModels['WoW'] = {} as ReadModelMetadata
config.readModels['Amazing'] = {} as ReadModelMetadata
replace(Booster, 'config', config)

const spyMyCall = spy(MyCommand, 'myCall')
const command = new MyCommand('1', true)
const register = new Register('request-id-1')
const registerSpy = spy(register, 'events')
await MyCommand.handle(command, register)

expect(registerSpy).to.have.been.calledOnceWithExactly(new MyEvent('1', 'WoW'))
expect(registerSpy).to.have.been.calledOnceWithExactly(new MyEvent('1', 'Amazing'))
// Example code
public static async handle(command: MyCommand, register: Register): Promise<void> {
const readModels = Booster.config.readModels
for (const readModelName in readModels) {
myCall(readModelName) MyEvent(command.ID, readModelName))

These are some files that might help you speed up your testing with Booster.

// <root_dir>/test/expect.ts
import * as chai from 'chai'


export const expect = chai.expect

This expect method will help you with some more additional methods like expect(<my_stub>).to.have.been.calledOnceWithExactly(<my_params..>)

# <root_dir>/.mocharc.yml
diff: true
require: 'ts-node/register'
- ts
package: './package.json'
recursive: true
reporter: 'spec'
timeout: 5000
full-trace: true
bail: true

Framework integration tests

Booster framework integration tests package is used to test the Booster project itself, but it is also an example of how a Booster application could be tested. We encourage developers to have a look at our Booster project repository.

Some integration tests highly depend on the provider chosen for the project, and the infrastructure is normally deployed in the cloud right before the tests run. Once tests are completed, the application is teared down.

There are several types of integration tests in this package:

  • Tests to ensure that different packages integrate as expected with each other.
  • Tests to ensure that a Booster application behaves as expected when it is hit by a client (a GraphQL client).
  • Tests to ensure that the application behaves in the same way no matter what provider is selected.