Testing with Jest

By default FlashList will mount all items in the test environment. You can use the following mock to setup measurements to prevent everything from mounting. You can also create your own mock.

Setup

Add the following line to your jest-setup.js file:

require("@shopify/flash-list/jestSetup");

To be sure, check if your jest.config.js file contains:

...
preset: 'react-native',
setupFiles: ['./jest-setup.js'],
...

Example

Here is an example of using @testing-library/react-native:

import React from "react";
import { render } from "@testing-library/react-native";

describe("MyFlashListComponent", () => {
  it("renders items", () => {
    const { getByText } = render(<MyFlashListComponent />);
    const element = getByText("Title of one of the items");
    // Do something with element ...
  });
});