Manipulate the HTTP Vary header for Deno, compatible with Browser. Based on https://github.com/jshttp/vary.
import { vary, append } from "https://deno.land/x/vary/mod.ts";Adds the given header field to the Vary response header.
This can be a string of a single field, a string of a valid Vary
header, or an array of multiple fields.
This will append the header if not already listed, otherwise leaves it listed in the current location.
// Append "Origin" to the Vary header of the response's header
vary(header, 'Origin')Adds the given header field to the Vary response header string header.
This can be a string of a single field, a string of a valid Vary header,
or an array of multiple fields.
This will append the header if not already listed, otherwise leaves it listed in the current location. The new header string is returned.
// Get header string appending "Origin" to "Accept, User-Agent"
append('Accept, User-Agent', 'Origin')