Validate Locale string in Golang

Question

I am trying to write Go code that will check whether or not a string represents a valid locale. From the documentation, I've gotten to here:

import "golang.org/x/text/language"

locale := "en"
tag, err := language.Parse(locale)
if err != nil {
    return errors.New("Invalid locale: " + locale)
}

I think that this should work, and it seems to work most of the time, but it doesn't always give me an error when I expect it to. For example, if I say locale := "bcd" I don't get an error.

What am I missing here?

Answer 1

bcd is a valid ISO 639-3 language code for the North Babar language, and by extension it's a valid locale name.