VTEX Test Tools

Add tests to your VTEX IO app in an instant 🚀

Table of Contents

• Install
• Usage
• API
  • React Component
  • React Hooks
  • Messages I18n
  • GraphQL

Install

yarn add -D @vtex/test-tools @apollo/react-testing react-intl@3

Usage

Add a new script to your react/package.json:

{
  "name": "my-io-app",
  "scripts": {
    "test": "vtex-test-tools test"
  }
}

Add these lines to your .vtexignore:

react/**/__tests__/**
react/**/__mocks__/**
react/**/__snapshots__/**
react/**/*.test.js
react/**/*.test.ts
react/**/*.test.tsx

Run in your terminal:

yarn test

If you're using TypeScript there are a few more steps.

Done! 🎉

Under the hood, we use Jest, so you can pass Jest flags as parameters: read the docs.

API

react module

The module react makes it easy to test VTEX IO React apps.

Example

import React from 'react'
import { render } from '@vtex/test-tools/react'
import HelloWorld from './HelloWorld'
 
test('should render the Hello!', () => {
  const { getByText } = render(<HelloWorld />)
 
  const element = getByText(/Hello!/)
 
  expect(element).toBeDefined()
})

This module uses @testing-library/react (RTL) under the hood, so most of its API is the same (read their docs here).

We added a few more features to the regular render function from RTL, such as a graphql and locale option. You can see more about them down below.

React Hooks

You can also test your custom hooks.

Example

import { hooks } from '@vtex/test-tools/react'
import useCustomHook from './useCustomHook'
 
const { renderHook, act } = hooks
 
it('counter should be one', async () => {
  const { result } = renderHook(() => useCustomHook())
 
  // This waits for the useEffect hook to be triggered and mutate hook state
  await act(() => Promise.resolve())
 
  expect(result.current).toBe(1)
})

The module uses @react-testing-library/react-hooks under the hood, to understand the reactHook function you can read its doc

Messages

We will automatically wrap your component with an IntlProvider with your app's messages/en-US.json messages.

You can change the default locale being used adding a config to your package.json. Example:

{
  "name": "my-awesome-io-app",
  "vtexTestTools": {
    "defaultLocale": "pt-BR"
  }
}

If you want to change the locale just in a test, you may pass the locale option. Example:

import React from 'react'
import { render } from '@vtex/test-tools/react'
import HelloWorld from './HelloWorld'
 
test('should render the example translated to portuguese', () => {
  const { getByText } = render(<HelloWorld />, { locale: 'pt' })
 
  const element = getByText(/Olá!/)
 
  expect(element).toBeDefined()
})

GraphQL

We automatically wrap your component with an Apollo's MockedProvider.

You can pass your mocked queries to it using the graphql option. Example:

import React from 'react'
import { render, flushPromises } from '@vtex/test-tools/react'
import GraphqlComponent from './GraphqlComponent'
import GET_BOOKS from './getBooks.graphql'
 
test('should render mock graphql responses', async () => {
  jest.useFakeTimers()
 
  const bookMock = {
    request: {
      query: GET_BOOKS,
    },
    result: {
      data: {
        books: [
          {
            id: 10,
            title: 'Hello',
          },
        ],
      },
    },
  }
 
  const { getByText } = render(<GraphqlComponent />, {
    graphql: { mocks: [bookMock] },
  })
 
  expect(getByText(/Loading/)).toBeDefined()
 
  await flushPromises()
  jest.runAllTimers()
 
  expect(getByText(/Hello/)).toBeDefined()
})

Examples

These are some common use cases that might be helpful to see how it's done:

Debugging tests in VS Code

Testing a React component

Testing a React Hook

TypeScript

Testing a component using CSS Modules

Testing a component using GraphQL

Testing a component using React Hooks

Testing a component translating in another locale

License

MIT © VTEX