negotiate_test.go

// Copyright 2022 Franklin "Snaipe" Mathieu.
//
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.

package htutil

import (
	"fmt"
	"net/http"
	"reflect"
	"sort"
	"testing"
)

func TestSortAcceptables(t *testing.T) {
	t.Parallel()

	tcases := []struct {
		In  []Acceptable
		Out []Acceptable
	}{
		// Test cases from RFC2616 14.1
		{
			In: []Acceptable{
				{Value: "text/*", Quality: 1.0},
				{Value: "text/html", Quality: 1.0},
				{Value: "text/html", Quality: 1.0, Params: map[string]string{"level": "1"}},
				{Value: "*/*", Quality: 1.0},
			},
			Out: []Acceptable{
				{Value: "text/html", Quality: 1.0, Params: map[string]string{"level": "1"}},
				{Value: "text/html", Quality: 1.0},
				{Value: "text/*", Quality: 1.0},
				{Value: "*/*", Quality: 1.0},
			},
		},
		{
			In: []Acceptable{
				{Value: "text/*", Quality: 0.3},
				{Value: "text/html", Quality: 0.7},
				{Value: "text/html", Quality: 1.0, Params: map[string]string{"level": "1"}},
				{Value: "text/html", Quality: 0.4, Params: map[string]string{"level": "2"}},
				{Value: "*/*", Quality: 0.5},
			},
			Out: []Acceptable{
				{Value: "text/html", Quality: 1.0, Params: map[string]string{"level": "1"}},
				{Value: "text/html", Quality: 0.7},
				{Value: "*/*", Quality: 0.5},
				{Value: "text/html", Quality: 0.4, Params: map[string]string{"level": "2"}},
				{Value: "text/*", Quality: 0.3},
			},
		},
	}

	for i, tcase := range tcases {
		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
			sort.Slice(tcase.In, func(i, j int) bool { return Acceptable.Less(tcase.In[i], tcase.In[j]) })
			if !reflect.DeepEqual(tcase.In, tcase.Out) {
				t.Fatalf("expected %v, got %v", tcase.Out, tcase.In)
			}
		})
	}
}

func TestNegotiateContent(t *testing.T) {
	t.Parallel()

	tcases := []struct {
		Header string
		Accept string
		Offers []string
		Expect string
	}{
		{
			Header: "Accept",
			Accept: "text/plain; q=0.1, application/json",
			Offers: []string{"text/plain", "application/json"},
			Expect: "application/json",
		},
		{
			Header: "Accept",
			Accept: "text/plain; q=0.1, application/json",
			Offers: []string{"text/plain"},
			Expect: "text/plain",
		},
		{
			Header: "Accept",
			Accept: "text/plain; q=0.1, application/json",
			Offers: []string{},
			Expect: "",
		},
		{
			Header: "Accept-Encoding",
			Accept: "gzip",
			Offers: []string{"identity", "gzip"},
			Expect: "gzip",
		},
		{
			Header: "Accept-Encoding",
			Accept: "<none>", // omit the "Accept-Encoding" header.
			Offers: []string{"identity"},
			Expect: "identity",
		},
		{
			Header: "Accept-Encoding",
			Accept: "", // empty "Accept-Encoding: " header
			Offers: []string{"identity"},
			Expect: "identity",
		},
		// "As long as the identity;q=0 or *;q=0 directives do not explicitly forbid the
		// identity value that means no encoding, the server must never return a 406 Not
		// Acceptable error."
		{
			Header: "Accept-Encoding",
			Accept: "gzip",
			Offers: []string{"identity"},
			Expect: "identity",
		},
		{
			Header: "Accept-Encoding",
			Accept: "gzip, identity; q=0",
			Offers: []string{"identity"},
			Expect: "",
		},
	}

	for i, tcase := range tcases {
		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
			hdr := http.Header{}
			if tcase.Accept != "<none>" {
				hdr.Set(tcase.Header, tcase.Accept)
			}

			actual, _ := NegotiateContent(hdr, tcase.Header, tcase.Offers...)
			if actual != tcase.Expect {
				t.Fatalf("expected %v, got %v", tcase.Expect, actual)
			}
		})
	}
}