web-renderer-test

SkillDev tools

Lets your agent add test cases to the web renderer.

Available today. Use it from your connected AI after setup.

Connect ahel once, and every AI you use reads what you have installed.

Then ask your AI: use the web-renderer-test skill

About this capability

Add a test case to the web renderer

What this skill tells your AI

The instructions your AI receives, as published by remotion-dev/remotion in .agents/skills/web-renderer-test/SKILL.md and read by ahel’s review.

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

  1. Add a new fixture in packages/web-renderer/src/test/fixtures.
  2. Important: Add the fixture to packages/web-renderer/src/test/Root.tsx to add a way to preview it.
  3. Add a new test in packages/web-renderer/src/test.
  4. Run bunx vitest src/test/video.test.tsx to execute the test.
  5. Important: Update packages/docs/docs/client-side-rendering/limitations.mdx to reflect the newly supported property.

Signals

GitHub stars
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Forks
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Last commit
Sep 2026
Advanced
Catalog kind
skill
Gateway key
web-renderer-test-remotion-dev
Source
github.com/remotion-dev/remotion