Nov 29, 2019 10:37:00

Firefox will have a “replay function” that can record and play back browser operations

Mozilla revealed that it was going to be equipped with a replay function that can record the operation on Firefox, play it back and rewind to the previous state, and that it has already been implemented in part of the Firefox development version Announced.

Replay

https://firefox-replay.com/

WebReplay-Mozilla | MDN
https://developer.mozilla.org/en-US/docs/Mozilla/Projects/WebReplay

This replay function is developed in a project called `` WebReplay '', and it can save most operations that occurred during recording, such as JavaScript operations and DOM structure, as well as updating graphics displayed on the browser That.

In order to perform debugging at high speed and intuitively, a timeline is set up on the debug screen, and code execution can be checked at a glance. Also, if you move the mouse cursor on the timeline, a DOM preview will be displayed. Mozilla says that the replay function timeline displays various points such as exceptions, events, and network requests in real time, making it easy to “pause and inspect the replay”.

In addition, since the replay function is supposed to be used by the team at the development site, the record by the replay function can be saved and read. Bugs that are difficult to reproduce are difficult to check by others, and debugging work may not proceed slowly, but by recording the operation with the replay function and sharing the record with others, efficiency is also great It is expected to go up.

Firefox's replay function is implemented only in the macOS version of Firefox Nightly , which is the development version at the time of article creation, and it is disabled by default until it stabilizes, so it needs to be enabled from the setting That's it. Since almost all of the implementation work was done on macOS, porting is necessary to implement it on the Windows version, but “Interfering system library API identification” “Memory management of rewind function” “Graphic processing different from macOS and Mozilla said that “handling interprocess communication” is difficult.