Check of an invalid date returns true on Firefox (isValid())

[JSeifBY]

The Issue isValid() not behaving the same on different browser, it returns false on Chrome / Safari as expected but returns true on Firefox.

The string that was sent to the validator has no relation with dates "JUNKIE (SWE)", see screenshot:

Chrome:

Fiirefox:

Expected behavior An invalid date should always returns false on all browsers the same way.

Information

• Day.js Version 1.10.7
• OS: MacOS
• Browser: Firefox 125.0.3
• Time zone: UTC+2

[vhnam]

hi @JSeifBY, i'm facing the same issue as you.

the root cause is the difference between FireFox and Chrome engines.

you can try with this function

new Date('JUNKIE (SWE)')

on Chrome

• expected: Invalid Date
• actual: Invalid Date

on Firefox

• expected: Invalid Date
• actual: Date Fri Jun 01 2001 00:00:00 GMT+0700 (Indochina Time)

I think we should raise this issue with Mozilla 😂