The web renderer is in packages/web-renderer and the test suite is in packages/web-renderer/src/test .

It uses visual snapshot testing using vitest. A test file can for example be executed using:

bunx vitest src/test/video.test.tsx

Example

Each test is powered by a fixture in packages/web-renderer/src/test/fixtures . A fixture looks like this for example:

import {AbsoluteFill} from 'remotion';

const Component: React.FC = () => { return ( <AbsoluteFill style={{ justifyContent: 'center', alignItems: 'center', }} > <div style={{ backgroundColor: 'red', width: 100, height: 100, borderRadius: 20, }} /> </AbsoluteFill> ); };

export const backgroundColor = { component: Component, id: 'background-color', width: 200, height: 200, fps: 25, durationInFrames: 1, } as const;

The corresponding test looks like this:

import {test} from 'vitest'; import {renderStillOnWeb} from '../render-still-on-web'; import {backgroundColor} from './fixtures/background-color'; import {testImage} from './utils';

test('should render background-color', async () => { const blob = await renderStillOnWeb({ licenseKey: 'free-license', composition: backgroundColor, frame: 0, inputProps: {}, imageFormat: 'png', });

await testImage({blob, testId: 'background-color'}); });

Adding a new test

• Add a new fixture in packages/web-renderer/src/test/fixtures .

• Important: Add the fixture to packages/web-renderer/src/test/Root.tsx to add a way to preview it.

• Add a new test in packages/web-renderer/src/test .

• Run bunx vitest src/test/video.test.tsx to execute the test.

• Important: Update packages/docs/docs/client-side-rendering/limitations.mdx to reflect the newly supported property.