Plural rules are broken for time diff strings

[TheoChevalier]

Screenshot of timeDiffHoursAgo in French https://screenshots.firefox.com/T7g56E2IcYW6yQkK/screenshots.firefox.com

According to the translation here, it should be 1 heure (without s) https://pontoon.mozilla.org/fr/firefox-screenshots/server.ftl/?search=timeDiffHoursAgo&string=168527

Flod pointed that there might be a problem here

screenshots/server/src/pages/shot/time-diff.js

Line 17 in 954a54d

return <Localized id={timeDiff.l10nID} $number={timeDiff.diff}><span title={this.dateString(this.props.date)}></span></Localized>

CC: @stasm @flodolo

[jaredhirsch]

@stasm Is it intended that passing the number 1 chooses the "one" plural, but passing the string "1" chooses the default, rather than coercing the string to a number?

this behavior is visible in the fluent playground:

"1" as a string:

1 as a number:

[stasm]

Oops, sorry I missed the notification here. I'm happy I didn't block you from fixing this.

To answer @6a68's question: yes, this is the intended behavior for two reasons:

• It's more flexible that way: developers can choose to parseInt. If Fluent coerced, developers wouldn't be able to choose not to.
• Some locales use different plural forms for integers and decimals, e.g. 1 is different from 1.0. I think English is one of them: 1 apple but 1.0 apples. The only way in JS to pass 1.0 and not lose the decimal part is to pass it as a string. (That said, fluent.js doesn't yet correctly support such numbers.)

[jaredhirsch]

@stasm Nah, not a problem. Good point re: decimal singular, I hadn't considered that.