[badminton1]

In this line: https://github.com/brannondorsey/host-validation/blob/2ba467... use Array.some rather than iterating through all elements with Array.filter.

Then this: https://github.com/brannondorsey/host-validation/blob/2ba467... is not something I would recommend. Don't try to fix bad input.

[braxxox]

#1, good call! #2, usually I am 100% in agreement. But referer vs referrer in the HTTP spec is a special case. I chose to do this as referer is misspelled in the spec itself.

[badminton1]

Does the misspelled version prevailed over the correct version if both are defined?

[braxxox]

It does as it is the correct header name.

[wild_preference]

If both keys exist, then it’s an even bigger signal of user mistake. Are you going to fail then? Distinction becomes pretty arbitrary.

As a user, I’d rather have a failure at boot time if I got it wrong. Just because I had a typo once doesn’t mean I always make it. What if I tried to transform my own config? I’d have to follow special case your referers property like you did to keep it consistent.

[badminton1]

May be a reasonable choice but I recommend just throwing.