add unsafe-url referrerPolicy test (#3772)

test/fetch/issue-3767.js

@@ -0,0 +1,30 @@
+'use strict'
+
+const { once } = require('node:events')
+const { createServer } = require('node:http')
+const { test } = require('node:test')
+const { fetch } = require('../..')
+const { tspl } = require('@matteo.collina/tspl')
+
+// https://github.com/nodejs/undici/issues/3767
+test('referrerPolicy unsafe-url is respected', async (t) => {
+  const { completed, deepEqual } = tspl(t, { plan: 1 })
+
+  const referrer = 'https://google.com/hello/world'
+
+  const server = createServer((req, res) => {
+    deepEqual(req.headers.referer, referrer)
+
+    res.end()
+  }).listen(0)
+
+  t.after(server.close.bind(server))
+  await once(server, 'listening')
+
+  await fetch(`http://localhost:${server.address().port}`, {
+    referrer,
+    referrerPolicy: 'unsafe-url'
+  })
+
+  await completed
+})