From f2e5f327aaf12b4572296ec6e107ecc05fcf76e7 Mon Sep 17 00:00:00 2001
From: iamkun <kunhello@outlook.com>
Date: Sat, 8 Aug 2020 14:08:44 +0800
Subject: [PATCH] fix: Fix isoWeek Plugin cal bug in UTC mode (#993)

---
 src/plugin/isoWeek/index.js |  6 +++---
 test/plugin/isoWeek.test.js | 10 ++++++++++
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/plugin/isoWeek/index.js b/src/plugin/isoWeek/index.js
index 79e6fab33..72018ffff 100644
--- a/src/plugin/isoWeek/index.js
+++ b/src/plugin/isoWeek/index.js
@@ -3,8 +3,8 @@ import { D, W, Y } from '../../constant'
 const isoWeekPrettyUnit = 'isoweek'
 
 export default (o, c, d) => {
-  const getYearFirstThursday = (year) => {
-    const yearFirstDay = d().year(year).startOf(Y)
+  const getYearFirstThursday = (year, isUtc) => {
+    const yearFirstDay = (isUtc ? d.utc : d)().year(year).startOf(Y)
     let addDiffDays = 4 - yearFirstDay.isoWeekday()
     if (yearFirstDay.isoWeekday() > 4) {
       addDiffDays += 7
@@ -26,7 +26,7 @@ export default (o, c, d) => {
       return this.add((week - this.isoWeek()) * 7, D)
     }
     const nowWeekThursday = getCurrentWeekThursday(this)
-    const diffWeekThursday = getYearFirstThursday(this.isoWeekYear())
+    const diffWeekThursday = getYearFirstThursday(this.isoWeekYear(), this.$u)
     return nowWeekThursday.diff(diffWeekThursday, W) + 1
   }
 
diff --git a/test/plugin/isoWeek.test.js b/test/plugin/isoWeek.test.js
index b86a6d6ae..b6ebc392b 100644
--- a/test/plugin/isoWeek.test.js
+++ b/test/plugin/isoWeek.test.js
@@ -2,8 +2,10 @@ import MockDate from 'mockdate'
 import moment from 'moment'
 import dayjs from '../../src'
 import isoWeek from '../../src/plugin/isoWeek'
+import utc from '../../src/plugin/utc'
 
 dayjs.extend(isoWeek)
+dayjs.extend(utc)
 
 beforeEach(() => {
   MockDate.set(new Date())
@@ -124,3 +126,11 @@ it('isoWeek of year', () => {
   expect(dayjs('20210110').isoWeekYear()).toBe(2021)
   expect(dayjs('20210110').isoWeek()).toBe(1)
 })
+
+
+it('utc mode', () => {
+  // Wednesday, 1 January 2020 00:00:00 UTC
+  const d = dayjs.utc(1577836800000).isoWeek()
+  expect(d).toBe(1)
+  expect(moment.utc(1577836800000).isoWeek()).toBe(d)
+})