callstack__react-native-testing-library/docs/Queries.md

id, title

id	title
api-queries	Queries

Variants

getBy queries are shown by default in the query documentation below.

getBy

getBy* queries returns the first matching node for a query, and throws an error if no elements match.

getAllBy

getAllBy* queries return an array of all matching nodes for a query, and throws an error if no elements match.

queryBy

queryBy* queries returns the first matching node for a query, and return null if no elements match. This is useful for asserting an element is not present.

queryAllBy

queryAllBy* queries return an array of all matching nodes for a query, and return an empty array ([]) if no elements match.

Queries

Note: most methods like this one return a ReactTestInstance with following properties that you may be interested in:

type ReactTestInstance = {
  type: string | Function,
  props: { [propName: string]: any },
  parent: null | ReactTestInstance,
  children: Array<ReactTestInstance | string>,
};

ByText

getByText, getAllByText, queryByText, queryAllByText

Returns a ReactTestInstance with matching text – may be a string or regular expression.

This method will join <Text> siblings to find matches, similarly to how React Native handles these components. This will allow for querying for strings that will be visually rendered together, but may be semantically separate React components.

import { render } from 'react-native-testing-library';

const { getByText } = render(<MyComponent />);
const element = getByText('banana');

ByPlaceholder

getByPlaceholder, getAllByPlaceholder, queryByPlaceholder, queryAllByPlaceholder

Returns a ReactTestInstance for a TextInput with a matching placeholder – may be a string or regular expression.

import { render } from 'react-native-testing-library';

const { getByPlaceholder } = render(<MyComponent />);
const element = getByPlaceholder('username');

ByTestId

getByTestId, getAllByTestId, queryByTestId, queryAllByTestId

Returns a ReactTestInstance with matching testID prop.

import { render } from 'react-native-testing-library';

const { getByTestId } = render(<MyComponent />);
const element = getByTestId('unique-id');

Unit testing helpers

Use sparingly and responsibly, escape hatches here

render from react-native-testing-library exposes additional queries that should not be used in component integration testing, but some users (like component library creators) interested in unit testing some components may find helpful.

Queries helpful in unit testing

The interface is the same as for other queries, but we won't provide full names so that they're harder to find by search engines.

ByType

Note: added in v1.4

A method returning a ReactTestInstance with matching a React component type. Throws when no matches.

ByProps

A method returning a ReactTestInstance with matching props object

ByName

This method has been deprecated because using it results in fragile tests that may break between minor React Native versions. DON'T USE IT. It will be removed in next major release (v2.0). Use getByTestId instead. It's listed here only for back-compat purposes for early adopters of the library

A method returning a ReactTestInstance with matching a React component type. Throws when no matches.