764600 - Send front-end errors to lattice

Status: RESOLVED FIXED

(Pancake Graveyard :: Front-end, defect)

Description

[Olivier Yiptong [:oyiptong]]

Send JS errors to the back-end for archival

Format can be seen here:
https://github.com/lincolnloop/raven-js/blob/develop/src/raven.js

Roughly:
[
{
            "message": label,
            "culprit": fileurl,
            "stacktrace": stacktrace,
            "exception": {
                "type": type,
                "value": message
            },
            "site": site,
            "timestamp": timestamp,
        }
]

A stacktrace looks like that:

stacktrace = {
                "frames": [{
                    "filename": fileurl,
                    "lineno": lineno
                }]
};

Comment 1

[Sam Foster [:sfoster] (he/him)]

Fixed with merge of error-logging branch and later fixes: 

https://bitbucket.org/mozillapancake/pancake/changeset/01214cf5bf8b
..to..
https://bitbucket.org/mozillapancake/pancake/changeset/ff90f8e2a740

This adds new logging architecture, exception and stacktrace preparation in lib/errors and a lib/logger/remoteexceptions module which packages the data up and sends to /lattice/exceptions

Also, when web.json has web.is_debug: true, you'll get a debug/dev toolbar rendered by root.mustache ('/'). Just hover/click the top of the page to show it, and to load the spec runners to run our unit tests. 

See sample output of the remote exception logger, e.g.:
http://play.fxhome.mozillalabs.com:9000/default/group/22/

There is more work to do on the stacktraces. When we catch thrown exceptions using window.onerror, we don't get a useful stacktrace. This needs to be fixed at the source of the error (the view, model/collection or controller) and handled/propogated correctly rather than left uncaught. That's a not-insignificant amount of work and worthy of its own ticket.

Comment 2

[Naoki Hirata :nhirata (please use needinfo instead of cc)]

How can I test for this?

Comment 3

[Sam Foster [:sfoster] (he/him)]

I've been doing 2 things:

1) intercept a lattice response with Charles or similar debugging proxy and break the JSON by either changing the name of a key, or triggering a parse error by removing a '}'

2) In the code (e.g. placecollection.js) adding an extra required field in the parse handler. 

#1 is probably more feasible for you. We don't have any special trigger-error back doors :)