feat(format): add and subtract

add time and sbtract time

src/constant.js

@@ -0,0 +1,4 @@
+export const SECONDS_A_MINUTE = 60
+export const SECONDS_A_HOUR = SECONDS_A_MINUTE * 60
+export const SECONDS_A_DAY = SECONDS_A_HOUR * 24
+export const SECONDS_A_WEEK = SECONDS_A_DAY * 7

src/index.js

@@ -1,3 +1,5 @@
+import * as Constant from './constant'
+
 class Dayjs {
   constructor(config) {
     this.utc = false
@@ -49,6 +51,36 @@ class Dayjs {
     }
   }
 
+  add(number, string) {
+    let step
+    switch (string) {
+      case 'm':
+      case 'minutes':
+        step = Constant.SECONDS_A_MINUTE
+        break
+      case 'h':
+      case 'hours':
+        step = Constant.SECONDS_A_HOUR
+        break
+      case 'd':
+      case 'days':
+        step = Constant.SECONDS_A_DAY
+        break
+      case 'w':
+      case 'weeks':
+        step = Constant.SECONDS_A_WEEK
+        break
+      default: // s seconds
+        step = 1
+    }
+    const nextTimeStamp = this.unix() + (number * step)
+    return new Dayjs(nextTimeStamp * 1000)
+  }
+
+  subtract(number, string) {
+    return this.add(number * -1, string)
+  }
+
   format(formatStr = 'YYYY-MM-DDTHH:mm:ssZ') {
     const weeks = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday']
     const { date } = this

test/manipulate.test.js

@@ -13,3 +13,19 @@ test('StartOf Other', () => {
   expect(dayjs().startOf('otherString').unix()).toBe(moment().startOf('otherString').unix())
 })
 
+test('Add Time days', () => {
+  expect(dayjs().add(1, 's').unix()).toBe(moment().add(1, 's').unix())
+  expect(dayjs().add(1, 'seconds').unix()).toBe(moment().add(1, 'seconds').unix())
+  expect(dayjs().add(1, 'm').unix()).toBe(moment().add(1, 'm').unix())
+  expect(dayjs().add(1, 'minutes').unix()).toBe(moment().add(1, 'minutes').unix())
+  expect(dayjs().add(1, 'h').unix()).toBe(moment().add(1, 'h').unix())
+  expect(dayjs().add(1, 'hours').unix()).toBe(moment().add(1, 'hours').unix())
+  expect(dayjs().add(1, 'w').unix()).toBe(moment().add(1, 'w').unix())
+  expect(dayjs().add(1, 'weeks').unix()).toBe(moment().add(1, 'weeks').unix())
+  expect(dayjs().add(1, 'd').unix()).toBe(moment().add(1, 'd').unix())
+  expect(dayjs().add(1, 'days').unix()).toBe(moment().add(1, 'days').unix())
+})
+
+test('Subtract Time days', () => {
+  expect(dayjs().subtract(1, 'days').unix()).toBe(moment().subtract(1, 'days').unix())
+})

test/parse.test.js

@@ -9,6 +9,11 @@ test('String 20130208', () => {
   expect(dayjs('20130208').unix()).toBe(moment('20130208').unix())
 })
 
+test('String timestamp 1523520536000 ms', () => {
+  const timestamp = 1523520536000
+  expect(dayjs(timestamp).unix()).toBe(moment(timestamp).unix())
+})
+
 test('String Other', () => {
   global.console.warn = jest.genMockFunction()// moment.js otherString will throw warn
   expect(dayjs('otherString').toString().toLowerCase()).toBe(moment('otherString').toString().toLowerCase())