Architecture

There are multiple layers to the library:

• ReactScreenshotTest is the library's main entrypoint.
  • It exposes a simple API.
  • Internally, it coordinates Jest, the component server and the screenshot renderer.
• ReactComponentServer is an HTTP server that renders React components server-side.
• ScreenshotRenderer is an interface wrapping a browser.
  • There are multiple implementations, in particular PuppeteerScreenshotRenderer (using Puppeteer) and PercyScreenshotRenderer (loading screenshots over HTTP).
• ScreenshotServer is an HTTP server that takes a screenshot of a particular URL.
  • A screenshot server can either be local or it can run within Docker.
  • Running it in Docker allows us to take consistent snapshots across platforms.