fix(add endof): add endOf && add startOf day

Author: iamkun

src/index.js

@@ -57,17 +57,32 @@ class Dayjs {
     return this.$date.toUTCString()
   }
 
-  startOf(arg) {
+  startOf(arg, isStartOf = true) {
     switch (arg) {
       case 'year':
-        return new Dayjs(new Date(this.year(), 0, 1))
+        if (isStartOf) {
+          return new Dayjs(new Date(this.year(), 0, 1))
+        }
+        return new Dayjs(new Date(this.year(), 11, 31)).endOf('day')
       case 'month':
-        return new Dayjs(new Date(this.year(), this.month(), 1))
+        if (isStartOf) {
+          return new Dayjs(new Date(this.year(), this.month(), 1))
+        }
+        return new Dayjs(new Date(this.year(), this.month() + 1, 0)).endOf('day')
+      case 'day':
+        if (isStartOf) {
+          return new Dayjs(this.toDate().setHours(0, 0, 0, 0))
+        }
+        return new Dayjs(this.toDate().setHours(23, 59, 59, 999))
       default:
-        return this
+        return this.clone()
     }
   }
 
+  endOf(arg) {
+    return this.startOf(arg, false)
+  }
+
   set(string, int) {
     if (!Utils.isNumber(int)) return this
     switch (string) {

test/manipulate.test.js

@@ -10,16 +10,24 @@ afterEach(() => {
   MockDate.reset()
 })
 
-it('StartOf Year', () => {
+it('StartOf EndOf Year', () => {
   expect(dayjs().startOf('year').unix()).toBe(moment().startOf('year').unix())
+  expect(dayjs().endOf('year').unix()).toBe(moment().endOf('year').unix())
 })
 
-it('StartOf Month', () => {
+it('StartOf EndOf Month', () => {
   expect(dayjs().startOf('month').unix()).toBe(moment().startOf('month').unix())
+  expect(dayjs().endOf('month').unix()).toBe(moment().endOf('month').unix())
 })
 
-it('StartOf Other', () => {
+it('StartOf EndOf Day', () => {
+  expect(dayjs().startOf('day').unix()).toBe(moment().startOf('day').unix())
+  expect(dayjs().endOf('day').unix()).toBe(moment().endOf('day').unix())
+})
+
+it('StartOf EndOf Other -> no change', () => {
   expect(dayjs().startOf('otherString').unix()).toBe(moment().startOf('otherString').unix())
+  expect(dayjs().endOf('otherString').unix()).toBe(moment().endOf('otherString').unix())
 })
 
 it('Add Time days', () => {