Back to Repositories

Validating German Locale Time Formatting in Day.js

This test suite validates the German locale functionality in Day.js, focusing on relative time formatting and regional language variations. It ensures proper handling of time expressions in German, Austrian German, and Swiss German dialects.

Test Coverage Overview

The test suite provides comprehensive coverage of relative time formatting in German locales:

Past and future time expressions with suffixes
Relative time without suffixes
Regional variations (de, de-at, de-ch)
Various time units from seconds to years
Comparison with moment.js implementation

Implementation Analysis

The testing approach utilizes Jest’s testing framework with MockDate for consistent date handling. Tests are structured to verify:

Correct suffix handling for past/future expressions
Proper grammatical forms for singular/plural cases
Regional dialect variations in date formatting
Parallel functionality with moment.js library

Technical Details

Testing infrastructure includes:

Jest as the primary testing framework
MockDate for date manipulation
Day.js with relativeTime plugin
Multiple locale imports (de, de-at, de-ch)
Moment.js for comparison testing

Best Practices Demonstrated

The test suite exemplifies several testing best practices:

Systematic test case organization using arrays
Consistent setup/teardown with beforeEach/afterEach
Comprehensive cross-library validation
Clear test descriptions and expectations
Efficient test case iteration across locales

iamkun/dayjs

test/locale/de.test.js

            
import MockDate from 'mockdate'
import moment from 'moment'
import dayjs from '../../src'
import relativeTime from '../../src/plugin/relativeTime'
import '../../src/locale/de'
import '../../src/locale/de-at'
import '../../src/locale/de-ch'

dayjs.extend(relativeTime)

beforeEach(() => {
  MockDate.set(new Date())
})

afterEach(() => {
  MockDate.reset()
})

it('German locale relative time in past and future with suffix', () => {
  const cases = [
    [1, 's', 'in ein paar Sekunden'],
    [-1, 's', 'vor ein paar Sekunden'],
    [1, 'm', 'in einer Minute'],
    [-1, 'm', 'vor einer Minute'],
    [1, 'h', 'in einer Stunde'],
    [-1, 'h', 'vor einer Stunde'],
    [1, 'd', 'in einem Tag'],
    [-1, 'd', 'vor einem Tag'],
    [1, 'M', 'in einem Monat'],
    [-1, 'M', 'vor einem Monat'],
    [2, 'd', 'in 2 Tagen'],
    [-2, 'd', 'vor 2 Tagen'],
    [10, 'd', 'in 10 Tagen'],
    [-10, 'd', 'vor 10 Tagen'],
    [6, 'm', 'in 6 Minuten'],
    [-6, 'm', 'vor 6 Minuten'],
    [5, 'h', 'in 5 Stunden'],
    [-5, 'h', 'vor 5 Stunden'],
    [3, 'M', 'in 3 Monaten'],
    [-3, 'M', 'vor 3 Monaten'],
    [4, 'y', 'in 4 Jahren'],
    [-4, 'y', 'vor 4 Jahren']
  ]

  const locales = ['de', 'de-at', 'de-ch']
  locales.forEach((locale) => {
    cases.forEach((c) => {
      expect(dayjs().add(c[0], c[1]).locale(locale).fromNow())
        .toBe(c[2])
      expect(dayjs().add(c[0], c[1]).locale(locale).fromNow())
        .toBe(moment().add(c[0], c[1]).locale(locale).fromNow())
    })
  })
})

it('German locale relative time in past and future without suffix', () => {
  const cases = [
    [1, 's', 'ein paar Sekunden'],
    [-1, 's', 'ein paar Sekunden'],
    [1, 'm', 'eine Minute'],
    [-1, 'm', 'eine Minute'],
    [1, 'h', 'eine Stunde'],
    [-1, 'h', 'eine Stunde'],
    [1, 'd', 'ein Tag'],
    [-1, 'd', 'ein Tag'],
    [2, 'd', '2 Tage'],
    [-2, 'd', '2 Tage'],
    [10, 'd', '10 Tage'],
    [-10, 'd', '10 Tage'],
    [6, 'm', '6 Minuten'],
    [-6, 'm', '6 Minuten'],
    [5, 'h', '5 Stunden'],
    [-5, 'h', '5 Stunden'],
    [3, 'M', '3 Monate'],
    [-3, 'M', '3 Monate'],
    [4, 'y', '4 Jahre'],
    [-4, 'y', '4 Jahre']
  ]

  const locales = ['de', 'de-at', 'de-ch']
  locales.forEach((locale) => {
    cases.forEach((c) => {
      expect(dayjs().add(c[0], c[1]).locale(locale).fromNow(true))
        .toBe(c[2])
      expect(dayjs().add(c[0], c[1]).locale(locale).fromNow(true))
        .toBe(moment().add(c[0], c[1]).locale(locale).fromNow(true))
    })
  })
})

it('German locales use region specific names', () => {
  const locales = [
    { locale: 'de', expectedFormattedDate: 'Mi., 19. Januar 2022' },
    { locale: 'de-at', expectedFormattedDate: 'Mi., 19. Jänner 2022' },
    { locale: 'de-ch', expectedFormattedDate: 'Mi, 19. Januar 2022' }
  ]

  locales.forEach((locale) => {
    const dayjsWithLocale = dayjs('2022-01-19').locale(locale.locale)
    expect(dayjsWithLocale.format('ddd, D. MMMM YYYY')).toEqual(locale.expectedFormattedDate)
  })
})