dayjs.updateLocale does not support setting invalidDate string

[Teajey]

I am migrating a project from Moment.js to Day.js, but this project relies on updateLocale to display nullish dates as -. I see that Day.js always returns the same constant string when a date is invalid:

dayjs/src/index.js

Line 254 in 0fdac93

if (!this.isValid()) return C.INVALID_DATE_STRING

Are there any plans to allow this string to be overridden in Day.js? And in the meantime, what's a good workaround?

Below I compare the behavior of Moment.js and Day.js

> const dayjs = require("dayjs");
undefined

> const moment = require("moment");
undefined

> moment(null).format()
'Invalid date'

> dayjs(null).format()
'Invalid Date'

> moment.updateLocale('en', { invalidDate: "-" })
Locale {
  ...
}

> moment(null).format()
'-'

> const updateLocale = require("dayjs/plugin/updateLocale");
undefined

> dayjs.extend(updateLocale);
[Function: v] {
  ...
}

> dayjs.updateLocale('en', { invalidDate: "-" });
{
  name: 'en',
  weekdays: [
    'Sunday',
    'Monday',
    'Tuesday',
    'Wednesday',
    'Thursday',
    'Friday',
    'Saturday'
  ],
  months: [
    'January',   'February',
    'March',     'April',
    'May',       'June',
    'July',      'August',
    'September', 'October',
    'November',  'December'
  ],
  invalidDate: '-'
}

> dayjs(null).format()
'Invalid Date'

[iamkun]

🎉 This issue has been resolved in version 1.10.6 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀