fix: Add IsoWeek plugin (#811)

src/plugin/isoWeek/index.js

@@ -0,0 +1,51 @@
+import { D, W, Y } from '../../constant'
+
+const isoWeekPrettyUnit = 'isoweek'
+
+export default (o, c, d) => {
+  const getYearFirstThursday = (year) => {
+    const yearFirstDay = d().year(year).startOf(Y)
+    let addDiffDays = 4 - yearFirstDay.isoWeekday()
+    if (yearFirstDay.isoWeekday() > 4) {
+      addDiffDays += 7
+    }
+    return yearFirstDay.add(addDiffDays, D)
+  }
+
+  const getCurrentWeekThursday = ins => ins.add((4 - ins.isoWeekday()), D)
+
+  const proto = c.prototype
+
+  proto.isoWeekYear = function () {
+    const nowWeekThursday = getCurrentWeekThursday(this)
+    return nowWeekThursday.year()
+  }
+
+  proto.isoWeek = function (week) {
+    if (!this.$utils().u(week)) {
+      return this.add((week - this.isoWeek()) * 7, D)
+    }
+    const nowWeekThursday = getCurrentWeekThursday(this)
+    const diffWeekThursday = getYearFirstThursday(this.isoWeekYear())
+    return nowWeekThursday.diff(diffWeekThursday, W) + 1
+  }
+
+  proto.isoWeekday = function (week) {
+    if (!this.$utils().u(week)) {
+      return this.day(this.day() % 7 ? week : week - 7)
+    }
+    return this.day() || 7
+  }
+
+  const oldStartOf = proto.startOf
+  proto.startOf = function (units, startOf) {
+    const utils = this.$utils()
+    const isStartOf = !utils.u(startOf) ? startOf : true
+    const unit = utils.p(units)
+    if (unit === isoWeekPrettyUnit) {
+      return isStartOf ? this.date(this.date() - (this.isoWeekday() - 1)).startOf('day') :
+        this.date((this.date() - 1 - (this.isoWeekday() - 1)) + 7).endOf('day')
+    }
+    return oldStartOf.bind(this)(units, startOf)
+  }
+}

test/plugin/isoWeekOfYear.test.js → test/plugin/isoWeek.test.js

@@ -1,8 +1,9 @@
 import MockDate from 'mockdate'
+import moment from 'moment'
 import dayjs from '../../src'
-import isoWeekOfYear from '../../src/plugin/isoWeekOfYear'
+import isoWeek from '../../src/plugin/isoWeek'
 
-dayjs.extend(isoWeekOfYear)
+dayjs.extend(isoWeek)
 
 beforeEach(() => {
   MockDate.set(new Date())
@@ -12,6 +13,34 @@ afterEach(() => {
   MockDate.reset()
 })
 
+it('get isoWeek', () => {
+  expect(dayjs().isoWeek()).toBe(moment().isoWeek())
+})
+
+it('set isoWeek', () => {
+  expect(dayjs().isoWeek(1).valueOf()).toBe(moment().isoWeek(1).valueOf())
+  expect(dayjs().isoWeek(52).valueOf()).toBe(moment().isoWeek(52).valueOf())
+})
+
+it('get isoWeekYear', () => {
+  expect(dayjs().isoWeekYear()).toBe(moment().isoWeekYear())
+})
+
+it('startOf/endOf isoWeek', () => {
+  const ISOWEEK = 'isoWeek'
+  expect(dayjs().startOf(ISOWEEK).valueOf()).toBe(moment().startOf(ISOWEEK).valueOf())
+  expect(dayjs().endOf(ISOWEEK).valueOf()).toBe(moment().endOf(ISOWEEK).valueOf())
+})
+
+it('isoWeekday', () => {
+  expect(dayjs().isoWeekday()).toBe(moment().isoWeekday())
+  expect(dayjs('20200301').isoWeekday(1).valueOf()).toBe(moment('20200301').isoWeekday(1).valueOf()) // Sunday this.day() -> 0
+  for (let i = 0; i < 7; i += 1) {
+    expect(dayjs().add(i, 'day').isoWeekday()).toBe(moment().add(i, 'day').isoWeekday())
+    expect(dayjs().isoWeekday(i).valueOf()).toBe(moment().isoWeekday(i).valueOf())
+  }
+})
+
 it('isoWeek of year', () => {
   expect(dayjs().isoWeek(1).isoWeek()).toBe(1)
   expect(dayjs().isoWeek(27).isoWeek()).toBe(27)

types/plugin/isoWeek.d.ts

@@ -0,0 +1,27 @@
+import { PluginFunc, QUnitType, ConfigType } from 'dayjs'
+
+declare const plugin: PluginFunc
+export = plugin
+
+type ISOUnitType = UnitType | 'isoWeek';
+
+declare module 'dayjs' {
+  interface Dayjs {
+    isoWeekYear(): number
+    isoWeek(): number
+    isoWeek(value: number): Dayjs
+
+    isoWeekday(): number
+    isoWeekday(value: number): Dayjs
+
+    startOf(unit: ISOUnitType): Dayjs
+
+    endOf(unit: ISOUnitType): Dayjs
+
+    isSame(date: ConfigType, unit?: ISOUnitType): boolean
+
+    isBefore(date: ConfigType, unit?: ISOUnitType): boolean
+
+    isAfter(date: ConfigType, unit?: ISOUnitType): boolean
+  }
+}