Capture NS_ERROR_FAILURE errors from Firefox

[benvinegar]

I've managed to reproduce these failures by trying to do a POST from an html page that is served from the local filesystem (e.g. file:///)

var request = new XMLHttpRequest();
request.open("POST", 'http://example.com', false);
request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
request.send('');

Unfortunately I cannot write a test for this without overwriting Object.prototype.toString.call. Maybe that's worthwhile anyways.

Example of a stack captured after this change:

{
    "project": "1",
    "logger": "javascript",
    "platform": "javascript",
    "request": {
        "headers": {
            "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:44.0) Gecko/20100101 Firefox/44.0"
        },
        "url": "file:///Users/xxx/Projects/sentry/index.html"
    },
    "exception": {
        "values": [{
            "type": "NS_ERROR_FAILURE",
            "value": "",
            "stacktrace": {
                "frames": [{
                    "filename": "file:///Users/xxx/Projects/sentry/index.html",
                    "lineno": 12,
                    "colno": 1,
                    "function": "?",
                    "in_app": true
                }, {
                    "filename": "[2]</Raven.prototype._wrapBuiltIns/</<@http://127.0.0.1:8002/dist/raven.js",
                    "lineno": 703,
                    "colno": 28,
                    "function": "?",
                    "in_app": false
                }]
            }
        }]
    },
    "culprit": "[2]</Raven.prototype._wrapBuiltIns/</<@http://127.0.0.1:8002/dist/raven.js",
    "message": "NS_ERROR_FAILURE: ",
    "extra": {
        "session:duration": 83
    },
    "event_id": "7784426458894fe4bd595d44505f3ec2"
}

[mattrobenolt]

Why not just do:

['[object Error]', '[object Exception]'].indexOf(objectPrototype.toString.call(what)) > -1

Then we only need to toString() once and if we need to add to this, just add to this array. This array could also be popped out into a constant for like, var ERROR_TYPES = ['[object Error]', '[object Exception]']

Other than this, seems reasonable.

[benvinegar]

IE8 doesn't have Array.prototype.indexOf.

I'll make an update – we don't need to get that fancy.

[mattrobenolt]

IE8 doesn't have Array.prototype.indexOf.

TIL

Ignore me then. :)

[benvinegar]

Note that we still don't parse out the frame correctly – these NS errors have a different stack format than regular Firefox errors.

[benvinegar]

I still think we can move ahead with accepting this though, since most frames will still be read correctly.