Zibi Braniecki [:zbraniecki][:gandalf] Assignee
	Description • 7 years ago

Fluent introduces a fallback mechanism to handle a scenario when the string is missing or unresolvable in one locale, and has to fallback on its fallback locale (currently always en-US, but in the future we may have a nicer fallback chain).

The mechanism works great, except that it generates a lot of noise in the console.

This is particularly noticable in the period between patch landing and migration because all non-en-US builds of such nightly will have missing strings.

Here's how it looks for `pl`:

```
L10nError: Unknown message: category-general
Ślad stosu:
L10nError@resource://gre/modules/Localization.jsm:106:5
messageFromContext@resource://gre/modules/Localization.jsm:359:17
keysFromContext/<@resource://gre/modules/Localization.jsm:426:25
keysFromContext@resource://gre/modules/Localization.jsm:420:3
formatWithFallback@resource://gre/modules/Localization.jsm:172:22
async*formatMessages@resource://gre/modules/Localization.jsm:204:12
translateElements@resource://gre/modules/DOMLocalization.jsm:572:32
async*translateRoots/<@resource://gre/modules/DOMLocalization.jsm:470:25
translateRoots@resource://gre/modules/DOMLocalization.jsm:470:7
onLanguageChange@resource://gre/modules/DOMLocalization.jsm:352:5
observe@resource://gre/modules/Localization.jsm:284:9
registerSource@resource://gre/modules/L10nRegistry.jsm:112:5
startup@resource://gre/modules/Extension.jsm:1829:7
async*startup@resource://gre/modules/Extension.jsm:1068:12
callBootstrapMethod@resource://gre/modules/addons/XPIProvider.jsm:4415:20
startInstall/<@resource://gre/modules/addons/XPIInstall.jsm:1855:13
async*startInstall@resource://gre/modules/addons/XPIInstall.jsm:1749:6
install@resource://gre/modules/addons/XPIInstall.jsm:1421:7
install@resource://gre/modules/addons/XPIInstall.jsm:2163:7
checkForBlockers@resource://gre/modules/addons/XPIInstall.jsm:1707:5
install@resource://gre/modules/addons/XPIInstall.jsm:1418:7
install@resource://gre/modules/addons/XPIInstall.jsm:2163:7
checkPrompt/<@resource://gre/modules/addons/XPIInstall.jsm:1682:7
async*checkPrompt@resource://gre/modules/addons/XPIInstall.jsm:1662:6
install@resource://gre/modules/addons/XPIInstall.jsm:1415:7
install@resource://gre/modules/addons/XPIInstall.jsm:2163:7
downloadCompleted/<@resource://gre/modules/addons/XPIInstall.jsm:2479:9
makeSafe/<@resource://gre/modules/addons/XPIProvider.jsm -> resource://gre/modules/addons/XPIProviderUtils.js:95:17
getRepositoryAddon@resource://gre/modules/addons/XPIProvider.jsm -> resource://gre/modules/addons/XPIProviderUtils.js:76:5
getAddon/<@resource://gre/modules/addons/XPIProvider.jsm -> resource://gre/modules/addons/XPIProviderUtils.js:722:9
promise callback*getAddon@resource://gre/modules/addons/XPIProvider.jsm -> resource://gre/modules/addons/XPIProviderUtils.js:720:12
getVisibleAddonForID@resource://gre/modules/addons/XPIProvider.jsm -> resource://gre/modules/addons/XPIProviderUtils.js:769:5
downloadCompleted@resource://gre/modules/addons/XPIInstall.jsm:2456:5
onStopRequest/<@resource://gre/modules/addons/XPIInstall.jsm:2402:13
promise callback*onStopRequest@resource://gre/modules/addons/XPIInstall.jsm:2400:9
```

and so on 19 times (number of messages added to en-US and not yet migrated in locales).

We should do a better job at presenting this as a single warning/message, rather than 19 errors.

	Francesco Lodolo [:flod]
	Comment 1 • 7 years ago

Personal take:
* We should reduce the noise, as you wrote. The UI is doing the right thing (falling back), one message as a warning would be enough.
* I don't think we should show this kind of warnings outside of Nightly (maybe Dev Edition). I don't see value added to the user by telling them about unknown l10n messages.

	Zibi Braniecki [:zbraniecki][:gandalf] Assignee
	Comment 2 • 7 years ago

A patch I just landed in fluent-dom fixes it - https://github.com/projectfluent/fluent.js/commit/3eb3709451c45df8b9a0a5505b8b5cdf02cefca1

While majority of the work to align the code between Gecko and fluent.js repo will go to bug 1434434, I believe it's worth downstreaming this single change into 60 since it vastly improves experience of working with the code.

	Staś Małolepszy :stas
	Comment 4 • 7 years ago
mozreview-review

Comment on attachment 8956374 [details]
Bug 1438608 - Improve error reporting of Fluent missing strings.

https://reviewboard.mozilla.org/r/225240/#review231220

	Pulsebot
	Comment 5 • 7 years ago

Pushed by zbraniecki@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/8381ed38af10
Improve error reporting of Fluent missing strings. r=stas

	Dorel Luca [:dluca]
	Comment 6 • 7 years ago
bugherder

https://hg.mozilla.org/mozilla-central/rev/8381ed38af10