Example

// src/__tests__/example.js
// query utilities:
import {
getByLabelText,
getByText,
getByTestId,
queryByTestId,
// Tip: all queries are also exposed on an object
// called "queries" which you could import here as well
waitFor,
} from '@testing-library/dom'
// adds special assertions like toHaveTextContent
import '@testing-library/jest-dom'
function getExampleDOM() {
// This is just a raw example of setting up some DOM
// that we can interact with. Swap this with your UI
// framework of choice ๐Ÿ˜‰
const div = document.createElement('div')
div.innerHTML = `
<label for="username">Username</label>
<input id="username" />
<button>Print Username</button>
`
const button = div.querySelector('button')
const input = div.querySelector('input')
button.addEventListener('click', () => {
// let's pretend this is making a server request, so it's async
// (you'd want to mock this imaginary request in your unit tests)...
setTimeout(() => {
const printedUsernameContainer = document.createElement('div')
printedUsernameContainer.innerHTML = `
<div data-testid="printed-username">${input.value}</div>
`
div.appendChild(printedUsernameContainer)
}, Math.floor(Math.random() * 200))
})
return div
}
test('examples of some things', async () => {
const famousProgrammerInHistory = 'Ada Lovelace'
const container = getExampleDOM()
// Get form elements by their label text.
// An error will be thrown if one cannot be found (accessibility FTW!)
const input = getByLabelText(container, 'Username')
input.value = famousProgrammerInHistory
// Get elements by their text, just like a real user does.
getByText(container, 'Print Username').click()
await waitFor(() =>
expect(queryByTestId(container, 'printed-username')).toBeTruthy(),
)
// getByTestId and queryByTestId are an escape hatch to get elements
// by a test id (could also attempt to get this element by its text)
expect(getByTestId(container, 'printed-username')).toHaveTextContent(
famousProgrammerInHistory,
)
// jest snapshots work great with regular DOM nodes!
expect(container).toMatchSnapshot()
})
Last updated on by Sidharth Vinod