feat: make lowercase localized formats fallback to slightly modified …

src/plugin/localizedFormat/index.js

@@ -9,19 +9,16 @@ export default (o, c, d) => {
     L: 'MM/DD/YYYY',
     LL: 'MMMM D, YYYY',
     LLL: 'MMMM D, YYYY h:mm A',
-    LLLL: 'dddd, MMMM D, YYYY h:mm A',
-    l: 'M/D/YYYY',
-    ll: 'MMM D, YYYY',
-    lll: 'MMM D, YYYY h:mm A',
-    llll: 'ddd, MMM D, YYYY h:mm A'
+    LLLL: 'dddd, MMMM D, YYYY h:mm A'
   }
   d.en.formats = englishFormats
-  proto.format = function (formatStr) {
-    const locale = this.$locale()
-    const formats = locale.formats || {}
-    const str = formatStr || FORMAT_DEFAULT
-    const result = str.replace(/(\[[^\]]+])|(LTS?|l{1,4}|L{1,4})/g, (_, a, b) =>
-      a || formats[b] || englishFormats[b])
+  const t = format => format.replace(/(\[[^\]]+])|(MMMM|MM|DD|dddd)/g, (_, a, b) => a || b.slice(1))
+  proto.format = function (formatStr = FORMAT_DEFAULT) {
+    const { formats = {} } = this.$locale()
+    const result = formatStr.replace(/(\[[^\]]+])|(LTS?|l{1,4}|L{1,4})/g, (_, a, b) => {
+      const B = b && b.toUpperCase()
+      return a || formats[b] || englishFormats[b] || t(formats[B])
+    })
     return oldFormat.call(this, result)
   }
 }

test/plugin/localizedFormat.test.js

@@ -2,6 +2,7 @@ import MockDate from 'mockdate'
 import moment from 'moment'
 import dayjs from '../../src'
 import es from '../../src/locale/es'
+import znCn from '../../src/locale/zh-cn'
 import localizedFormat from '../../src/plugin/localizedFormat'
 
 dayjs.extend(localizedFormat)
@@ -17,7 +18,7 @@ afterEach(() => {
 it('Declares English localized formats', () => {
   expect(dayjs.en).toBeDefined()
   expect(dayjs.en.formats).toBeDefined();
-  ['LT', 'LTS', 'L', 'LL', 'LLL', 'LLLL', 'l', 'll', 'lll', 'llll'].forEach(option =>
+  ['LT', 'LTS', 'L', 'LL', 'LLL', 'LLLL'].forEach(option =>
     expect(dayjs.en.formats[option]).toBeDefined())
 })
 
@@ -30,20 +31,35 @@ it('Should not interpolate characters inside square brackets', () => {
   expect(actualDate.format('YYYY [l] YYYY')).toBe('1970 l 1970')
   expect(actualDate.format('l [l] l')).toBe('1/1/1970 l 1/1/1970')
   expect(actualDate.format('[L LL LLL LLLL]')).toBe(expectedDate.format('[L LL LLL LLLL]'))
+
+
+  const localeFormats = {
+    L: '[MMMM MM DD dddd]'
+  }
+  const mockedDayJsLocale = {
+    ...es,
+    name: 'fake-locale',
+    formats: {
+      ...localeFormats
+    }
+  }
+  const fakeDate = dayjs(date, { locale: mockedDayJsLocale })
+
+  expect(fakeDate.locale('fake-locale').format('l')).toEqual('MMMM MM DD dddd')
 })
 
 it('Recognizes localized format options', () => {
   const { formats } = dayjs.en
   const date = dayjs();
-  ['LT', 'LTS', 'L', 'LL', 'LLL', 'LLLL', 'l', 'll', 'lll', 'llll'].forEach(option =>
+  ['LT', 'LTS', 'L', 'LL', 'LLL', 'LLLL'].forEach(option =>
     expect(date.format(option)).toBe(date.format(formats[option])))
 })
 
 it('Uses correct English formats', () => {
   const date = new Date()
   const actualDate = dayjs(date)
   const expectedDate = moment(date);
-  ['LT', 'LTS', 'L', 'LL', 'LLL', 'LLLL', 'l', 'll', 'lll', 'llll'].forEach(option =>
+  ['LT', 'LTS', 'L', 'LL', 'LLL', 'LLLL'].forEach(option =>
     expect(actualDate.format(option)).toBe(expectedDate.format(option)))
 })
 
@@ -72,3 +88,21 @@ it('Uses the locale of the dayjs instance', () => {
   const spanishDate = dayjs(date, { locale: es })
   expect(englishDate.format('L LTS')).not.toBe(spanishDate.format('L LTS'))
 })
+
+
+it('Uses the localized lowercase formats if defined', () => {
+  const date = new Date()
+  const znDate = dayjs(date, { locale: znCn });
+  ['l', 'll', 'lll', 'llll'].forEach(option => expect(znDate.format(option)).toBe(znDate.format(znCn.formats[option])))
+})
+
+it('Uses the localized uppercase formats as a base for lowercase formats, if not defined', () => {
+  const date = new Date()
+  const spanishDate = dayjs(date, { locale: es });
+
+  ['l', 'll', 'lll', 'llll'].forEach((option) => {
+    const upperCaseFormat = es.formats[option.toUpperCase()]
+    const adaptedFormat = upperCaseFormat.replace(/(\[[^\]]+])|(MMMM|MM|DD|dddd)/g, (_, a, b) => a || b.slice(1))
+    expect(spanishDate.format(option)).toBe(spanishDate.format(adaptedFormat))
+  })
+})