973188 - Make the Developer HUD API nicer for Gaia test integration

Status: RESOLVED FIXED

(Firefox OS Graveyard :: Gaia, defect)

Description

[Jan Keromnes [:janx]]

The Developer HUD's main objective is to help web developers notice problems in their apps.

While the HUD has already proved useful in manual testing, it would make even more sense to hook it up to Gaia tests and prevent future changes from introducing new problems unnoticed (e.g. too many reflows, too much jank, memory leaks, etc).

Comment 1

[Jan Keromnes [:janx]]

Note to self: Make the Developer HUD event-based, allowing other to listen in.

Comment 2

[Jan Keromnes [:janx]]

Attachment: Make the Developer HUD API nicer for Gaia test integration. r=21

Comment 3

[Jan Keromnes [:janx]]

WIP.

The current proposal is to use the 'developer-hud-update' event sent on the System App to notify front-end view and tests that a metric has changed.

- The event's target will be the frame that caused the metric change.
- The event's detail will look like: `{app:app://manifest.webapp, metric:jank, value:112, message:'jank: 112ms'}`.
- To listen to it you could proceed like so: https://github.com/mozilla-b2g/gaia/blob/master/apps/system/js/devtools_view.js#L11

Etienne and Hubert, would that work well for you?

TODO:
- Figure out good names for the Target prototype methods.
- Remove the `event.detail.metrics` field by making the front-end update metrics individually.
- Make logging depend on a pref.
- Fix FIXMEs, do TODOs.

Comment 4

[Jan Keromnes [:janx]]

Attachment: Make the Developer HUD API nicer for Gaia test integration. r=21

Comment 5

[Jan Keromnes [:janx]]

Comment on attachment 8389132 [details] [diff] [review]
Make the Developer HUD API nicer for Gaia test integration. r=21

Vivien, does this make sense to you?

Comment 6

[Hubert Figuiere [:hub]]

yeah that would work.

Comment 7

[Vivien Nicolas (:vingtetun) (:21) - (NOT reading bugmails, needinfo? please)]

Comment on attachment 8389132 [details] [diff] [review]
Make the Developer HUD API nicer for Gaia test integration. r=21

Review of attachment 8389132 [details] [diff] [review]:
-----------------------------------------------------------------

::: b2g/chrome/content/devtools.js
@@ +250,5 @@
> +    this.update(metric, this.metrics.get(metric) + 1, message);
> +  },
> +
> +  /**
> +   * Void a metric value and make sure isn't displayed on the front-end anymore.

s/isn't/it isn't ?

Comment 8

[Jan Keromnes [:janx]]

Dietrich, just giving you the heads up that this changes the logging format a bit. It will look like:

> I/GeckoDump( 2201): DeveloperHUD: [app://system.gaiamobile.org/manifest.webapp] reflow: 2.78ms
> I/GeckoDump( 2201): DeveloperHUD: [app://keyboard.gaiamobile.org/manifest.webapp] jank: 146ms

Additionally, you can also watch app metrics by listening for 'developer-hud-update' events on the System App (see comment #3).

Caveat: Changes to the 'memory' metric (app window memory, we have no uss info yet) are sent as events, but are not dumped in the console. Would you like them to be dumped as well?

Comment 9

[Jan Keromnes [:janx]]

Attachment: Make the Developer HUD API nicer for Gaia test integration. r=21

Comment 10

[Jan Keromnes [:janx]]

Comment on attachment 8389303 [details] [diff] [review]
Make the Developer HUD API nicer for Gaia test integration. r=21

Review of attachment 8389303 [details] [diff] [review]:
-----------------------------------------------------------------

21's r+

Comment 11

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/integration/fx-team/rev/7a6b4371379f

Comment 12

[Dietrich Ayala (:dietrich)]

Thanks Jan!

Comment 13

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/7a6b4371379f