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Testing with Jest

Since FlashList does not immediately render but waits for the size of the underlying ScrollView (unless you specify estimatedListSize), we need to mock triggering onLayout event.

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 ...
});
});