feat(useDateFormat): support dd, ddd and dddd formatter

packages/shared/useDateFormat/index.md

@@ -26,9 +26,14 @@ Get the formatted date according to the string of tokens passed in, inspired by
 | `ss`   | 00-59            | The second, 2-digits                  |
 | `SSS`  | 000-999          | The millisecond, 3-digits             |
 | `d`    | 0-6              | The day of the week, with Sunday as 0 |
+| `dd`   | S-S              | The min name of the day of the week   |
+| `ddd`  | Sun-Sat          | The short name of the day of the week |
+| `dddd` | Sunday-Saturday  | The name of the day of the week       |
 
 ## Usage
 
+### Basic
+
 ```html
 <script setup lang="ts">
 
@@ -43,3 +48,20 @@ const formatted = useDateFormat(useNow(), 'YYYY-MM-DD HH:mm:ss')
   <div>{{ formatted }}</div>
 </template>
 ```
+
+### Use with locale
+
+```html
+<script setup lang="ts">
+
+import { ref, computed } from 'vue-demi'
+import { useNow, useDateFormat } from '@vueuse/core'
+
+const formatted = useDateFormat(useNow(), 'YYYY-MM-DD (ddd)', { locales: 'en-US' })
+
+</script>
+
+<template>
+  <div>{{ formatted }}</div>
+</template>
+```

packages/shared/useDateFormat/index.test.ts

@@ -28,4 +28,13 @@ describe('useDateFormat', () => {
   it('should work with HH:mm:ss d', () => {
     expect(useDateFormat(new Date('2022-01-01 15:05:05'), 'HH:mm:ss d').value).toBe('15:05:05 6')
   })
+  it('should work with YYYY/MM/DD dd', () => {
+    expect(useDateFormat(new Date('2022-01-01 15:05:05'), 'YYYY/MM/DD dd', { locales: 'en-US' }).value).toBe('2022/01/01 S')
+  })
+  it('should work with YYYY/MM/DD ddd', () => {
+    expect(useDateFormat(new Date('2022-01-01 15:05:05'), 'YYYY/MM/DD ddd', { locales: 'en-US' }).value).toBe('2022/01/01 Sat')
+  })
+  it('should work with YYYY/MM/DD dddd', () => {
+    expect(useDateFormat(new Date('2022-01-01 15:05:05'), 'YYYY/MM/DD dddd', { locales: 'en-US' }).value).toBe('2022/01/01 Saturday')
+  })
 })

packages/shared/useDateFormat/index.ts

@@ -4,10 +4,19 @@ import { computed } from 'vue-demi'
 
 export type DateLike = Date | number | string | undefined
 
+export interface UseDateFormatOptions {
+  /**
+   * The locale(s) to used for dd/ddd/dddd format
+   *
+   * [MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl#locales_argument).
+   */
+  locales?: Intl.LocalesArgument
+}
+
 const REGEX_PARSE = /* #__PURE__ */ /^(\d{4})[-/]?(\d{1,2})?[-/]?(\d{0,2})[Tt\s]*(\d{1,2})?:?(\d{1,2})?:?(\d{1,2})?[.:]?(\d+)?$/
 const REGEX_FORMAT = /* #__PURE__ */ /\[([^\]]+)]|Y{1,4}|M{1,4}|D{1,2}|d{1,4}|H{1,2}|h{1,2}|a|A|m{1,2}|s{1,2}|Z{1,2}|SSS/g
 
-export const formatDate = (date: Date, formatStr: string) => {
+export const formatDate = (date: Date, formatStr: string, locales?: Intl.LocalesArgument) => {
   const years = date.getFullYear()
   const month = date.getMonth()
   const days = date.getDate()
@@ -16,25 +25,28 @@ export const formatDate = (date: Date, formatStr: string) => {
   const seconds = date.getSeconds()
   const milliseconds = date.getMilliseconds()
   const day = date.getDay()
-  const matches: Record<string, string | number> = {
-    YY: String(years).slice(-2),
-    YYYY: years,
-    M: month + 1,
-    MM: `${month + 1}`.padStart(2, '0'),
-    D: String(days),
-    DD: `${days}`.padStart(2, '0'),
-    H: String(hours),
-    HH: `${hours}`.padStart(2, '0'),
-    h: `${hours % 12 || 12}`.padStart(1, '0'),
-    hh: `${hours % 12 || 12}`.padStart(2, '0'),
-    m: String(minutes),
-    mm: `${minutes}`.padStart(2, '0'),
-    s: String(seconds),
-    ss: `${seconds}`.padStart(2, '0'),
-    SSS: `${milliseconds}`.padStart(3, '0'),
-    d: day,
+  const matches: Record<string, () => string | number> = {
+    YY: () => String(years).slice(-2),
+    YYYY: () => years,
+    M: () => month + 1,
+    MM: () => `${month + 1}`.padStart(2, '0'),
+    D: () => String(days),
+    DD: () => `${days}`.padStart(2, '0'),
+    H: () => String(hours),
+    HH: () => `${hours}`.padStart(2, '0'),
+    h: () => `${hours % 12 || 12}`.padStart(1, '0'),
+    hh: () => `${hours % 12 || 12}`.padStart(2, '0'),
+    m: () => String(minutes),
+    mm: () => `${minutes}`.padStart(2, '0'),
+    s: () => String(seconds),
+    ss: () => `${seconds}`.padStart(2, '0'),
+    SSS: () => `${milliseconds}`.padStart(3, '0'),
+    d: () => day,
+    dd: () => date.toLocaleDateString(locales, { weekday: 'narrow' }),
+    ddd: () => date.toLocaleDateString(locales, { weekday: 'short' }),
+    dddd: () => date.toLocaleDateString(locales, { weekday: 'long' }),
   }
-  return formatStr.replace(REGEX_FORMAT, (match, $1) => $1 || matches[match])
+  return formatStr.replace(REGEX_FORMAT, (match, $1) => $1 || matches[match]())
 }
 
 export const normalizeDate = (date: DateLike) => {
@@ -63,10 +75,11 @@ export const normalizeDate = (date: DateLike) => {
  * @see https://vueuse.org/useDateFormat
  * @param date
  * @param formatStr
+ * @param options
  */
 
-export function useDateFormat(date: MaybeComputedRef<DateLike>, formatStr: MaybeComputedRef<string> = 'HH:mm:ss') {
-  return computed(() => formatDate(normalizeDate(resolveUnref(date)), resolveUnref(formatStr)))
+export function useDateFormat(date: MaybeComputedRef<DateLike>, formatStr: MaybeComputedRef<string> = 'HH:mm:ss', options: UseDateFormatOptions = {}) {
+  return computed(() => formatDate(normalizeDate(resolveUnref(date)), resolveUnref(formatStr), options?.locales))
 }
 
 export type UseDateFormatReturn = ReturnType<typeof useDateFormat>