If you don’t want users leaving the app you have to think of performance. In fact nowadays if you site is not fast enough you get even “honored” with the badge of shame from Google. Thus performance budget is one of the aspects we address with end-to-end tests and include in CI/CD pipeline to ensure new releases do comply our requirements.

With Puppetry we can assert that:

• Page loading times comply given restrictions

• Total weight of assets (JavaScript, CSS, images, media, fonts, XHR) requested on the page satisfies given budget.

• Total number of requested of assets satisfies given budget

Milestone timings

With page.assertPerformanceTiming method we can establish budget for loading times. Namely:

• Page loading: the whole process of navigation and page load

• Redirection: the time taken by document request redirections

• Network latency: the time taken to fetch app cache, lookup domain, establish TCP connection, send request, receive response

• Page processing: the time taken for page load once the page is received from the server

In case of assertion failure we get a report like this:

Quantity-based metrics

With page.assertPerformanceAssetWeight method we can assert the total weight of assets (JavaScript, CSS, images, media, fonts, XHR) requested on the page

In case of assertion failure we get a report like this:

By clicking on Download performance report

we can get the network activity details

With page.assertPerformanceAssetCount method we can assert the total number of assets (JavaScript, CSS, images, media, fonts, XHR) requested on the page