is-language-code^4.0.14

Presets:
initial fr private use zh-cmn-Hans-CN en-US tag with ext subtag in primary 2 ext same prefix nothing

Is this a valid language code?
✅  Yes, it is a valid language code.

TIP: check out RFC 5646
TIP #2: check out a regex ietf-language-tag-regex by ~sebinsua on npm