I am trying to retrieve a particular request header from an apolloserver request (i.e. the request object from a GraphQLRequestContext), inside a a plugin.
logging the headers object logs out as:
Headers {
[Symbol(map)]: [Object: null prototype] {
'content-type': [ 'application/json' ],
user: [
'{...(redacted)...}'
],
'x-header-foo': [ '234' ],
accept: [ '*/*' ],
'content-length': [ '256' ],
'user-agent': [ 'node-fetch/1.0 (+https://github.com/bitinn/node-fetch)' ],
'accept-encoding': [ 'gzip,deflate' ],
connection: [ 'close' ],
host: [ 'localhost:3000' ]
}
}
but headers['x-header-foo'] yields undefined. How do I get the header value? I have not used symbols much so far.
As you said rightly, Headers are Symbols and not Objects, so to get value, you use the get method
Read more about Symbols here Symbol is a built-in object whose constructor returns a symbol primitive — also called a Symbol value or just a Symbol — that's guaranteed to be unique.
Headers are Symbols and not Objects, so to get value, you use the get method
const host = req.headers.get("host"); // stackoverflow.com
If you wish to destructure using Symbols:
let symbol = Symbol()
let obj = { [symbol] : 'value'}
let { [symbol]: alias } = obj
console.log(alias)