@formatjs/intl-messageformat, 10.5.0: Plural rules aren't applied correctly

[git-decadent]

Which package?

@formatjs/intl-messageformat @ 10.5.0

Describe the bug

The problem is related to how the plural rule is applied to the string, which is translated using react.i18next in conjunction with i18next-icu where intl-messageformat is a peer dependency. Initially, I suspected the issue lay with i18next-icu. However, during debugging, I traced it back to this line of code:

    const rule = formatters
          .getPluralRules(locales, {type: el.pluralType})
          .select((value as number) - (el.offset || 0))

Translations json:

export default {
    selectedCalendars: '{calendars, plural, =1 {one selected calendar} other {# selected calendars}}',
};

The use-case:

import i18next from "i18next";
import ICU from "i18next-icu";

i18next.use(ICU).init({
   ...
});

// Correct: "one selected calendar"
i18next.t("selectedCalendars", { calendars: 1 }); 

// Wrong: "{calendars, plural, =1 {one selected calendar} other {# selected calendars}}"
i18next.t("selectedCalendars", { calendars: 2 }); 

None of the rules like other, many, one, etc are functioning correctly. intl-messageformat throws an error, specifically: [TypeError: Cannot read property 'fn' of undefined]. This error occurs when the formatters.getPluralRules() invokes select() here.

If I remove the arguments passed to select() call like below, everything works as expected:

    var rule = formatters
        .getPluralRules(locales, { type: el.pluralType })
        .select();

To Reproduce

See the section Describe the bug

Expected behavior

Correct translation rules for plurals.

Smartphone (please complete the following information):

• Device: iPhone 11, iPhone 15 in xCode simulator
• OS: iOS 17.3. iOS 17.0
• React Native App:
  "react": "~18.2.0",
  "react-i18next": "~13.3.1",
  "react-native": "~0.72.0",
  "i18next-icu": "~2.3.0",
  "intl-messageformat": "10.5.0",
  "@formatjs/intl-locale": "~3.4.5",
  "@formatjs/intl-pluralrules": "~5.2.12",

Additional context

The issue might stem from @formatjs/intl-pluralrules.

[git-decadent]

More debugging traced it to intl-pluralrules where the locale parameter passed to PluralRuleSelect() is undefined.

Then later this error [TypeError: Cannot read property 'fn' of undefined] takes place here.

[git-decadent]

Apparently, my app was missing localeData to be imported.
So my bad.