fix: improve utc plugin when 0 offset and keepLocalTime (#1778)

iamkun · Oct 15, 2024 · e553ece · e553ece
1 parent e720cfe
commit e553ece
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diff --git a/src/plugin/utc/index.js b/src/plugin/utc/index.js
@@ -89,8 +89,16 @@ export default (option, Dayjs, dayjs) => {
     const offset = Math.abs(input) <= 16 ? input * 60 : input
     let ins = this
     if (keepLocalTime) {
+      const isUTCBefore = !!ins.$u
       ins.$offset = offset
       ins.$u = input === 0
+      if (isUTCBefore) {
+        return ins
+      }
+      if (ins.$u && offset === 0) {
+        // notUTC to UTC and keep localTime , should offset
+        return ins.add(oldUtcOffset.call(ins), MIN)
+      }
       return ins
     }
     if (input !== 0) {

diff --git a/test/plugin/utc-utcOffset.test.js b/test/plugin/utc-utcOffset.test.js
@@ -13,6 +13,21 @@ afterEach(() => {
   MockDate.reset()
 })
 
+it('utcOffset return clone object', () => {
+  const original = dayjs()
+  const clone = original.utcOffset(0, true)
+  expect(original !== clone).toBeTruthy()
+})
+
+it('add minute after 0 utcOffset', () => {
+  const du = dayjs().add(1, 'minute').utcOffset(0, true)
+  const mu = moment().add(1, 'minute').utcOffset(0, true)
+  const duu = dayjs().utcOffset(0, true).add(1, 'minute')
+  const muu = moment().utcOffset(0, true).add(1, 'minute')
+  expect(duu.format()).toEqual(mu.format())
+  expect(du.format()).toEqual(muu.format())
+})
+
 it('Set utcOffset -> Get utcOffset', () => {
   expect(dayjs().utcOffset(540).utcOffset()).toBe(moment().utcOffset(540).utcOffset())
   expect(dayjs().utcOffset(540).format()).toBe(moment().utcOffset(540).format())