1790448 - Collect reach/impression/exposure(?) events for `backgroundTaskMessage` experiments

Status: NEW

(Toolkit :: Background Tasks, enhancement, P3)

Description

[Nick Alexander :nalexander [he/him]]

At the moment, backgroundTaskMessage experiments collect "enrollment" (and "unenrollment") Nimbus events. (And this is working in the wild; see queries like this one.)

After Bug 1788960, background task message experiments that pop toast notifications will collect Nimbus events saying when the browser was launched to "complete" a toast notification.

What's missing is a "reach" or "exposure" event each time a toast notification is actually displayed. Nimbus has some support for such "exposure" events but it must not be enabled for backgroundTaskMessage feature. This ticket tracks using this support, or adding Toast Notification-specific Glean telemetry to capture this situation.

This isn't highest priority because the immediate use case, toast notifications when Firefox is background updated to 106, will have a lifetime cap of 1 "exposure", so that "enrollment" is synonymous with "exposure".

Comment 1

[Nick Alexander :nalexander [he/him]]

barret: can you comment on how this is supposed to work? What I would like is to get an event each time a toast notification will be displayed. Do I simply need to add backgroundTaskMessage to REACH_EVENT_GROUPS and update the telemetry definitions?

Comment 2

[Beth Rennie [:beth] (she/her)]

Tracing throught the code, it seems like adding backgroundTaskMessage to REACH_EVENT_GROUPS is all that is necessary. Make sure to add backgroundTaskMessage to https://searchfox.org/mozilla-central/source/toolkit/components/telemetry/Events.yaml#1295 as well so telemetry knows about the message type.