Network & Console

Each button makes the browser do something a test can watch from outside the page, for example with Selenium BiDi (network and log events). The result also shows below.

Fetch JSON Request that fails (500) Log to the console Throw a JavaScript error Cause a CSP violation

This page is sent with the header Content-Security-Policy-Report-Only: img-src 'self', so loading a data: image is reported (but not blocked).