feat(format): format to string

format dayjs object to a string

src/index.js

@@ -3,6 +3,8 @@ class Dayjs {
     this.utc = false
     const args = this.parseConfig(config)
     this.date = new Date(args)
+    this.timeZone = this.date.getTimezoneOffset() / 60
+    this.timeZoneString = String(this.timeZone * -1).replace(/^(.)?(\d)/, '$10$200').padStart(5, '+')
   }
 
   parseConfig(config) {
@@ -27,7 +29,8 @@ class Dayjs {
   }
 
   unix() {
-    const zonePad = this.utc ? this.date.getTimezoneOffset() * 60 * 1000 : 0
+    // timezone(hour) * 60 * 60 * 1000 => ms
+    const zonePad = !this.utc ? 0 : this.timeZone * 60 * 60 * 1000
     return Math.floor((this.date.getTime() + zonePad) / 1000)
   }
 
@@ -45,6 +48,57 @@ class Dayjs {
         return this
     }
   }
+
+  format(formatStr = 'YYYY-MM-DDTHH:mm:ssZ') {
+    const weeks = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday']
+    const { date } = this
+    const year = date.getFullYear()
+    const month = date.getMonth() + 1
+    const day = date.getDate()
+    const week = date.getDay()
+    const hour = date.getHours()
+    const minute = date.getMinutes()
+    const second = date.getSeconds()
+
+    return formatStr.replace(/Y{2,4}|M{1,2}|D{1,2}|d{1,4}|H{1,2}|m{1,2}|s{1,2}|Z{1,2}/g, (match) => {
+      switch (match) {
+        case 'YY':
+          return String(year).slice(-2)
+        case 'YYYY':
+          return String(year)
+        case 'M':
+          return String(month)
+        case 'MM':
+          return String(month).padStart(2, '0')
+        case 'D':
+          return String(day)
+        case 'DD':
+          return String(day).padStart(2, '0')
+        case 'd':
+          return String(week)
+        case 'dddd':
+          return weeks[week]
+        case 'H':
+          return String(hour)
+        case 'HH':
+          return String(hour).padStart(2, '0')
+        case 'm':
+          return String(minute)
+        case 'mm':
+          return String(minute).padStart(2, '0')
+        case 's':
+          return String(second)
+        case 'ss':
+          return String(second).padStart(2, '0')
+        case 'Z':
+          return this.timeZoneString.replace('00', ':00')
+        case 'ZZ':
+          return this.timeZoneString
+        default:
+          return match
+      }
+    })
+  }
 }
 
 export default config => (

test/display.test.js

@@ -0,0 +1,52 @@
+import moment from 'moment'
+import dayjs from '../src'
+
+test('Format no formatStr', () => {
+  expect(dayjs().format()).toBe(moment().format())
+})
+
+test('Format Year YY YYYY', () => {
+  expect(dayjs().format('YY')).toBe(moment().format('YY'))
+  expect(dayjs().format('YYYY')).toBe(moment().format('YYYY'))
+})
+
+test('Format Month M MM', () => {
+  expect(dayjs().format('M')).toBe(moment().format('M'))
+  expect(dayjs().format('MM')).toBe(moment().format('MM'))
+})
+
+test('Format Day of Month D DD 1 - 31', () => {
+  expect(dayjs().format('D')).toBe(moment().format('D'))
+  expect(dayjs().format('DD')).toBe(moment().format('DD'))
+})
+
+test('Format Day of Week d Sun - Sat', () => {
+  expect(dayjs().format('d')).toBe(moment().format('d'))
+  expect(dayjs().format('dddd')).toBe(moment().format('dddd'))
+})
+
+test('Format Hour H HH 24-hour', () => {
+  expect(dayjs().format('H')).toBe(moment().format('H'))
+  expect(dayjs().format('HH')).toBe(moment().format('HH'))
+})
+
+test('Format Minute m mm', () => {
+  expect(dayjs().format('m')).toBe(moment().format('m'))
+  expect(dayjs().format('mm')).toBe(moment().format('mm'))
+})
+
+test('Format Second s sss', () => {
+  expect(dayjs().format('s')).toBe(moment().format('s'))
+  expect(dayjs().format('ss')).toBe(moment().format('ss'))
+})
+
+test('Format Time Zone ZZ', () => {
+  expect(dayjs().format('Z')).toBe(moment().format('Z'))
+  expect(dayjs().format('ZZ')).toBe(moment().format('ZZ'))
+})
+
+test('Format Complex with other string - : / ', () => {
+  const string = 'YY-M-D / HH:mm:ss'
+  expect(dayjs().format(string)).toBe(moment().format(string))
+})
+