render-result-naming-convention.md

Enforce a valid naming for return value from render (testing-library/render-result-naming-convention)

The name wrapper is old cruft from enzyme and we don't need that here. The return value from render is not "wrapping" anything. It's simply a collection of utilities that you should actually not often need anyway.

Rule Details

This rule aims to ensure the return value from render is named properly.

Ideally, you should destructure the minimum utils that you need from render, combined with using queries from screen object. In case you need to save the collection of utils returned in a variable, its name should be either view or utils, as render is not wrapping anything: it's just returning a collection of utilities. Every other name for that variable will be considered invalid.

To sum up these rules, the allowed naming convention for return value from render is:

• destructuring
• view
• utils

Examples of incorrect code for this rule:

import { render } from '@testing-library/framework';

// ...

// return value from `render` shouldn't be kept in a var called "wrapper"
const wrapper = render(<SomeComponent />);

import { render } from '@testing-library/framework';

// ...

// return value from `render` shouldn't be kept in a var called "component"
const component = render(<SomeComponent />);

import { render } from '@testing-library/framework';

// ...

// to sum up: return value from `render` shouldn't be kept in a var called other than "view" or "utils"
const somethingElse = render(<SomeComponent />);

Examples of correct code for this rule:

import { render } from '@testing-library/framework';

// ...

// destructuring return value from `render` is correct
const { unmount, rerender } = render(<SomeComponent />);

import { render } from '@testing-library/framework';

// ...

// keeping return value from `render` in a var called "view" is correct
const view = render(<SomeComponent />);

import { render } from '@testing-library/framework';

// ...

// keeping return value from `render` in a var called "utils" is correct
const utils = render(<SomeComponent />);

Further Reading

• Common Mistakes with React Testing Library
• render Result