DROPME e2e/udp/cmd/server: server test WIP

=== RUN   TestUDPOverHTTP
    server_test.go:41: 1
        h
        4
        ello

    server_test.go:41: 5
        hello

    server_test.go:41: 5
        hello

    server_test.go:41: 5
        hello

    server_test.go:41: 5
        hello

    server_test.go:41: 5
        hello

    server_test.go:41: 5
        hello

    server_test.go:41: 5
        hello

    server_test.go:41: 5
        hello

    server_test.go:41: 5
        hello

--- PASS: TestUDPOverHTTP (1.12s)
PASS

e2e/udp/cmd/server/server_test.go

@@ -0,0 +1,49 @@
+// Copyright 2022-2024 Sauce Labs Inc., all rights reserved.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+package main
+
+import (
+	"io"
+	"net/http"
+	"testing"
+	"time"
+)
+
+func TestUDPOverHTTP(t *testing.T) {
+	pr, pw := io.Pipe()
+	defer pr.Close()
+	defer pw.Close()
+
+	req, err := http.NewRequest(http.MethodGet, "http://localhost:3128/.well-known/masque/udp/localhost/5005", pr)
+	if err != nil {
+		t.Fatal(err)
+	}
+	req.Header.Set("Connection", "Upgrade")
+	req.Header.Set("Upgrade", "connect-udp")
+	req.ContentLength = -1
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	go func() {
+		for i := 0; i < 10; i++ {
+			pw.Write([]byte("hello"))
+			time.Sleep(100 * time.Millisecond)
+		}
+	}()
+
+	buf := make([]byte, 1000)
+	for i := 0; i < 10; i++ {
+		n, err := resp.Body.Read(buf)
+		if err != nil {
+			t.Fatal(err)
+		}
+		t.Log(string(buf[:n]))
+	}
+}