summercms/admin/tests/app/i18n.test.ts

import { beforeEach, describe, expect, it } from 'vitest'
import {
  availableLocales,
  currentLocale,
  interpolate,
  loadStrings,
  message,
  pluralCategory,
  setBundle,
  t,
  tc,
} from '../../src/app/i18n'
import { API, mockApi, queryOf, requestsTo } from '../helpers'
import { langFixture } from '../fixtures/typed'

beforeEach(() => {
  setBundle(langFixture.data, 'pl')
})

describe('interpolate (parity with phrasebook.interpolate)', () => {
  it('replaces :name, :Name and :NAME with the plain, first-upper and upper value', () => {
    expect(interpolate(':name / :Name / :NAME', { name: 'ada' })).toBe('ada / Ada / ADA')
  })

  it('replaces the longer placeholder first so :names never loses to :name', () => {
    expect(interpolate(':names and :name', { name: 'one', names: 'many' })).toBe('many and one')
    expect(interpolate(':name and :names', { names: 'many', name: 'one' })).toBe('one and many')
  })

  it('accepts a leading colon on the parameter name and skips an empty name', () => {
    expect(interpolate('Hello :who', { ':who': 'world' })).toBe('Hello world')
    expect(interpolate('Hello :', { ':': 'x', '': 'y' })).toBe('Hello :')
  })

  it('upper-cases the first code point, not the first UTF-16 unit', () => {
    expect(interpolate(':Name', { name: 'łódź' })).toBe('Łódź')
    expect(interpolate(':Name', { name: '𝒶bc' })).toBe('𝒶bc')
  })

  it('stringifies numbers and leaves text without placeholders or params alone', () => {
    expect(interpolate(':count items', { count: 3 })).toBe('3 items')
    expect(interpolate('plain', { name: 'x' })).toBe('plain')
    expect(interpolate(':name')).toBe(':name')
    expect(interpolate('', { name: 'x' })).toBe('')
  })
})

describe('plural selection', () => {
  it.each([
    [1, 'one'],
    [2, 'few'],
    [5, 'many'],
    [22, 'few'],
    [25, 'many'],
  ])('pl %i is %s', (count, category) => {
    expect(pluralCategory(count, 'pl')).toBe(category)
  })

  it.each([
    [1, 'one'],
    [2, 'other'],
  ])('en %i is %s', (count, category) => {
    expect(pluralCategory(count, 'en')).toBe(category)
  })

  it('answers other for a locale Intl cannot parse', () => {
    expect(pluralCategory(1, '!!invalid!!')).toBe('other')
  })

  it('uses the bundle locale by default', () => {
    setBundle(langFixture.data, 'en')
    expect(pluralCategory(2)).toBe('other')
    setBundle(langFixture.data, 'pl')
    expect(pluralCategory(2)).toBe('few')
  })

  it('picks the form for the count and falls back to other when that form is missing', () => {
    const forms = { one: ':count plik', other: ':count pliku' }
    expect(message(forms, 1)).toBe('1 plik')
    expect(message(forms, 5)).toBe('5 pliku')
    expect(message(forms, 2, { count: 'dwa' })).toBe('dwa pliku')
  })

  it('renders other without a count and nothing without forms', () => {
    expect(message({ other: 'Hi :name', one: 'x' }, undefined, { name: 'Ada' })).toBe('Hi Ada')
    expect(message(null)).toBe('')
    expect(message(undefined, 3)).toBe('')
    expect(message({ one: 'only one' }, 5)).toBe('')
  })
})

describe('bundle lookups', () => {
  it('t returns the key itself when the key is not in the bundle', () => {
    expect(t('backend::lang.missing.key')).toBe('backend::lang.missing.key')
    expect(tc('backend::lang.missing.key', 3)).toBe('backend::lang.missing.key')
  })

  it('t interpolates the other form and tc the plural form', () => {
    expect(t('backend::lang.form.remove_item', { name: 'Ada' })).toBe('Usuń: Ada')
    expect(tc('backend::lang.list.results', 1)).toBe('1 wynik')
    expect(tc('backend::lang.list.results', 3)).toBe('3 wyniki')
    expect(tc('backend::lang.list.results', 7)).toBe('7 wyników')
  })

  it('setBundle replaces the strings and sets the document language', () => {
    setBundle({ 'backend::lang.auth.title': { other: 'Welcome back' } }, 'en')
    expect(t('backend::lang.auth.title')).toBe('Welcome back')
    expect(t('backend::lang.auth.submit')).toBe('backend::lang.auth.submit')
    expect(document.documentElement.lang).toBe('en')
    expect(currentLocale.value).toBe('en')
  })

  it('setBundle without a locale keeps the current locale', () => {
    setBundle({}, 'pl')
    setBundle({ a: { other: 'b' } })
    expect(currentLocale.value).toBe('pl')
    expect(t('a')).toBe('b')
  })
})

describe('loadStrings', () => {
  it('loads GET /lang and adopts meta.locale', async () => {
    const calls = mockApi({
      [`GET ${API}/lang`]: { body: { data: { 'backend::lang.auth.title': { other: 'Hello' } }, meta: { locale: 'en' } } },
    })
    await loadStrings()
    expect(requestsTo(calls, 'GET', `${API}/lang`)).toHaveLength(1)
    expect(t('backend::lang.auth.title')).toBe('Hello')
    expect(currentLocale.value).toBe('en')
  })

  it('sends the preferred locale as ?locale= and keeps meta.locales', async () => {
    const calls = mockApi({
      [`GET ${API}/lang`]: { body: { data: {}, meta: { locale: 'en', locales: ['en', 'pl'] } } },
    })
    await loadStrings('en')
    const [request] = requestsTo(calls, 'GET', `${API}/lang`)
    expect(queryOf(request!).get('locale')).toBe('en')
    expect(availableLocales.value).toEqual(['en', 'pl'])
    expect(currentLocale.value).toBe('en')
  })

  it('sends no locale without a preference and follows a shorter meta.locales', async () => {
    const calls = mockApi({
      [`GET ${API}/lang`]: { body: { data: {}, meta: { locale: 'pl', locales: ['pl'] } } },
    })
    await loadStrings()
    await loadStrings('')
    for (const request of requestsTo(calls, 'GET', `${API}/lang`)) {
      expect(queryOf(request).has('locale')).toBe(false)
    }
    expect(availableLocales.value).toEqual(['pl'])
  })

  it('keeps the current strings when the bundle cannot be loaded', async () => {
    mockApi({ [`GET ${API}/lang`]: { status: 500, body: { error: { code: 'server', message: 'x', details: {} } } } })
    await loadStrings()
    expect(t('backend::lang.auth.title')).toBe('Witaj ponownie')
    expect(currentLocale.value).toBe('pl')
  })
})