Why should we do toLowerCase to header name (by normalizeName()) ?

Code first:

fetch( url, {
    headers:{
        'Cookie':'some key-value pass to server',
        'User-Agent': 'react-native Android'
    }
);

I found that the name of headers has been converted to lower case by normalizeName .

And when I use it on React-Native (Android platform) , it send a HTTP request with lower case header name which not be recognized in our Server.

There is the row HTTP text I’ve capture:

GET http://... HTTP/1.1
cookie: ...
user-agent: react-native Android 

So. Why should we do toLowerCase to header name ?

[amrdraz]

While Http headers should be case-insensitive, a server for a client we’re dealing with has miss implemented the spec. They check authorization header using equality it seems and accordingly produce an error.

We do not have control over modifying the code of that server, we can submit a request but that will take time to process.

If according to the spec the header should be case-insensitive I don’t see why forcing the headers to be lower case matters then, we should be generally allowed to send headers in any case form.

[mislav]

@kobvel That’s correct.