DiscofyAPI/node_modules/helmet/dist/middlewares/referrer-policy/index.js

29 lines
1.1 KiB
JavaScript

"use strict"
Object.defineProperty(exports, "__esModule", { value: true })
const ALLOWED_TOKENS = new Set(["no-referrer", "no-referrer-when-downgrade", "same-origin", "origin", "strict-origin", "origin-when-cross-origin", "strict-origin-when-cross-origin", "unsafe-url", ""])
function getHeaderValueFromOptions({ policy = ["no-referrer"] }) {
const tokens = typeof policy === "string" ? [policy] : policy
if (tokens.length === 0) {
throw new Error("Referrer-Policy received no policy tokens")
}
const tokensSeen = new Set()
tokens.forEach(token => {
if (!ALLOWED_TOKENS.has(token)) {
throw new Error(`Referrer-Policy received an unexpected policy token ${JSON.stringify(token)}`)
} else if (tokensSeen.has(token)) {
throw new Error(`Referrer-Policy received a duplicate policy token ${JSON.stringify(token)}`)
}
tokensSeen.add(token)
})
return tokens.join(",")
}
function referrerPolicy(options = {}) {
const headerValue = getHeaderValueFromOptions(options)
return function referrerPolicyMiddleware(_req, res, next) {
res.setHeader("Referrer-Policy", headerValue)
next()
}
}
module.exports = referrerPolicy
exports.default = referrerPolicy