1668242 - Fix under-reporting of printing errors in telemetry

Status: RESOLVED FIXED

(Toolkit :: Printing, task, P1)

Description

[Jonathan Watt [:jwatt]]

In PrintUtils._displayPrintingError we record print error telemetry for errors that occur in the platform code when trying to create and reflow the print/print preview document. As far as I can tell we do not have any equivalent code to report errors that occur in the frontend code, or specifically errors that occur when trying to gather printer capabilities in the frontend code. We therefore have no idea how common these are.

Comment 1

[Mark Striemer [:mstriemer]]

What calls are expected to return errors?

Would it be the unrwiteable margins [1] and printer support/settings [2]? These promises would reject I suppose?

Is there a list of errors we should be expecting?

[1] https://searchfox.org/mozilla-central/rev/dfd9c0f72f9765bd4a187444e0c1e19e8834a506/toolkit/components/printing/content/print.js#851
[2] https://searchfox.org/mozilla-central/rev/dfd9c0f72f9765bd4a187444e0c1e19e8834a506/toolkit/components/printing/content/print.js#884-888

Comment 2

[Jonathan Watt [:jwatt]]

We'll really need to audit the code to answer that question, but basically gathering printer information is unreliable at almost any point. So the nsIPrinterList interface and the other interfaces accessed via it could all potentially fail.

Comment 3

[Emma Malysz]

Attachment: Bug 1668242, report printing errors in telemetry in the frontend

Comment 4

[Jonathan Watt [:jwatt]]

If at some point we find that the printing error rate is higher with the new UI than the old UI, in addition to the work being done in this bug, we should also be catching more printing errors due to the more robust code described in bug 1653340 comment 11.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e340b4d515fa
report printing errors in telemetry in the frontend r=mstriemer

Comment 6

[Dorel Luca [:dluca]]

https://hg.mozilla.org/mozilla-central/rev/e340b4d515fa