macOS 10.13
Add an XHR breakpoint
XHR breakpoints pause execution when certain XHR requests are sent by your web content. They’re listed in the XHR Breakpoints section of the left sidebar in the Debugger tab.
In the XHR Breakpoints section of the left sidebar, click the Add button (+), then enter a string or regular expression to pause only if the request URL matches part of the string or expression (or use the All Requests special breakpoint to pause on all outgoing XHR requests).
When an XHR breakpoint is hit, the Pause Reason section displays the requested URL and the call stack leading up to the call that caused the request.
