perf: refine code

Author: PanJiaChen

src/utils/index.js

@@ -9,7 +9,7 @@
  * @returns {string | null}
  */
 export function parseTime(time, cFormat) {
-  if (arguments.length === 0  && time != null) {
+  if (arguments.length === 0 || !time) {
     return null
   }
   const format = cFormat || '{y}-{m}-{d} {h}:{i}:{s}'

tests/unit/utils/parseTime.spec.js

@@ -1,4 +1,5 @@
 import { parseTime } from '@/utils/index.js'
+
 describe('Utils:parseTime', () => {
   const d = new Date('2018-07-13 17:54:01') // "2018-07-13 17:54:01"
   it('timestamp', () => {
@@ -24,4 +25,8 @@ describe('Utils:parseTime', () => {
   it('empty argument', () => {
     expect(parseTime()).toBeNull()
   })
+
+  it('null', () => {
+    expect(parseTime(null)).toBeNull()
+  })
 })