Bug: Crash with missing pluralization key

[kiskoza]

Description

My app's main language is English, but it needs to support a few others, e.g.: Arabic. Arabic does not have the same pluralization rules as English, so I had to add a custom code to use "zero", "one", "two", etc. Unfortunately there are some missing translations in the app, where I need to fall back to English. However, when the pluralization key is not present, it crashes instead of giving the usual error message.

How to reproduce

import { I18n } from "i18n-js";

const i18n = new I18n({
  "ar": {
    "weeks": {
      "one": "1 week ago",
      "other": "%{count} weeks ago"
    }
  }
});

i18n.pluralization.register('ar', (_i18n, count) => {
  // Based on https://github.com/ruby-i18n/i18n/blob/master/test/test_data/locales/plurals.rb
  if (count === 0) {
    return ['zero'];
  }
  if (count === 1) {
    return ['one'];
  }
  if (count === 2) {
    return ['two'];
  }
  if ([3, 4, 5, 6, 7, 8, 9, 10].includes(count % 100)) {
    return ['few'];
  }
  if (Number.isInteger(count)) {
    return ['many'];
  }

  return ['other'];
});

i18n.locale = 'ar';

console.log(i18n.t("not_existing", { count: 1 })); // -> [missing "ar.not_existing" translation]
console.log(i18n.t("weeks", { count: 1 })); // -> 1 week ago
console.log(i18n.t("weeks", { count: 2 })); // -> Uncaught TypeError: message is undefined

What do you expect

It would be nice to get the same fallback as I have for missing keys (e.g.: [missing "ar.weeks.two" translation] )

What happened instead

It raises an error and the whole page crashes.

Software:

• Package version: i18n-js@4.2.0
• Browser: Firefox 104

Full backtrace

Uncaught TypeError: message is undefined
    interpolate ./node_modules/i18n-js/dist/import/helpers/interpolate.js:7
    pluralize ./node_modules/i18n-js/dist/import/helpers/pluralize.js:26
    pluralize ./node_modules/i18n-js/dist/import/I18n.js:118
    translate ./node_modules/i18n-js/dist/import/I18n.js:87
    <anonymous> ./src/index.js:43

[fnando]

Thanks for reporting! I just released v4.2.1 with a fix for this.

[kiskoza]

Thanks, that was really quick. Upgraded the package version an it works for me 👍