core bug with locale plugin

[titanism]

> dayjs('4/23/22', 'M/DD/YY').locale('en').format('LT')
'12:00 AM'
> dayjs('4/23/22', 'M/DD/YY').locale('en').format('LTS')
'12:00:00 AM'
> dayjs('4/23/22', 'M/DD/YY').locale('en').format('L')
'04/23/2022'
> dayjs('4/23/22', 'M/DD/YY').locale('en').format('LL')
'April 23, 2022'
> dayjs('4/23/22', 'M/DD/YY').locale('en').format('LLL')
'April 23, 2022 12:00 AM'
> dayjs('4/23/22', 'M/DD/YY').locale('en').format('LLLL')
'Saturday, April 23, 2022 12:00 AM'
> dayjs('4/23/22', 'M/DD/YY').locale('en').format('l')
Uncaught TypeError: Cannot read properties of undefined (reading 'replace')
    at /Users/user/Projects/web/node_modules/.pnpm/dayjs@1.11.7/node_modules/dayjs/plugin/localizedFormat.js:1:676
    at String.replace (<anonymous>)
    at /Users/user/Projects/web/node_modules/.pnpm/dayjs@1.11.7/node_modules/dayjs/plugin/localizedFormat.js:1:563
    at r.format (/Users/user/Projects/web/node_modules/.pnpm/dayjs@1.11.7/node_modules/dayjs/plugin/localizedFormat.js:1:761)
    at e.format (/Users/user/Projects/web/node_modules/.pnpm/dayjs@1.11.7/node_modules/dayjs/plugin/preParsePostFormat.js:1:592)
    at u.format (/Users/user/Projects/web/node_modules/.pnpm/dayjs@1.11.7/node_modules/dayjs/plugin/utc.js:1:1655)
> dayjs('4/23/22', 'M/DD/YY').locale('zh').format('l')
'2022/4/23'
> dayjs('4/23/22', 'M/DD/YY').locale('de').format('l')
'23.4.2022'

As you can see, there is an uncaught typeerror above for "l", "ll", "lll", and "llll" usage for certain locales, e.g. en.

[titanism]

The reason is because the englishFormats object does not contain it.

dayjs/src/plugin/localizedFormat/utils.js

Lines 5 to 12 in 00c223b

	export const englishFormats = {
	LTS: 'h:mm:ss A',
	LT: 'h:mm A',
	L: 'MM/DD/YYYY',
	LL: 'MMMM D, YYYY',
	LLL: 'MMMM D, YYYY h:mm A',
	LLLL: 'dddd, MMMM D, YYYY h:mm A'
	}

Needs to have l, ll, lll, and llll added. Will submit a PR now.

[titanism]

This has been tested. Confirmed my PR works per #2282.

Please merge and release to npm with patch version bump.

Ping me back once done please! Thank you @iamkun.

> dayjs('4/23/22', 'M/DD/YY').locale('en').format('l') // this is with the PR
'4/23/2022'

[tendguo]

I don't agree with your conclusion, because I looked up the source code and found this

const B = b && b.toUpperCase()
return a || formats[b] || englishFormats[b] || t(formats[B])

[titanism]

@tendguo you are incorrect as that output is undefined, and you get an uncaught exception TypeError. From my tests on the latest version of dayjs it is an error when you require all the locales and then run the above commands.

[iamkun]

there should be no problem with localizedFormat plugin

https://runkit.com/embed/yzvddg5czfg6