1485339 - Only load ASR snippets when experiment is enabled

Status: RESOLVED WORKSFORME

(Firefox :: Messaging System, defect, P2)

Description

[Giorgos Logiotatidis [:giorgos]]

STR:

On current nightly 63.0a1 (2018-08-22) with `browser.newtabpage.activity-stream.asrouterExperimentEnabled` set to `true` I see from the Network tab of DevTools that nightly requests Snippets for the pre-ASR implementation (URLs starting with /5/...) 


Expectation:

Firefox must only request snippets for the implementation currently in use. 

Otherwise we risk significant increase in CDN costs if/when we enable the experiment for a larger population.

Comment 1

[Andrei Oprea [:andreio]]

By default ASRouter is disabled so starting up Firefox will do a request for the pre-ASR implementation and then when ASR is toggled on, another request for the new implementation. This is what I think happened here.
Checking AS code in 62 [0] looks like pre-ASR implementation will not initialize if ASR is enabled and similarly in current FFx 64.

[0] https://github.com/mozilla/activity-stream/blob/57cb70837328043b25ae8d9374c2c35d64a1d0dd/content-src/lib/snippets.js#L386

Comment 2

[Giorgos Logiotatidis [:giorgos]]

Thanks for taking the time to check Andrei. I also re-checked on up-to-date nightly and I cannot reproduce the issue.