From 2edb81edbb53e502fa5ca621e7e7d94b136a8771 Mon Sep 17 00:00:00 2001
From: rekby <timofey.koolin@gmail.com>
Date: Sat, 9 Apr 2022 14:58:00 +0300
Subject: [PATCH] Fix redirect double slash

---
 internal/proxy/http-proxy.go      |  4 +-
 internal/proxy/http-proxy_test.go | 61 ++++++++++++++++++++++++++++++-
 internal/th/fixenv.go             |  4 +-
 internal/th/fixtures.go           | 35 ++++++++++++++++++
 4 files changed, 98 insertions(+), 6 deletions(-)

diff --git a/internal/proxy/http-proxy.go b/internal/proxy/http-proxy.go
index 469e6163..ac32429c 100644
--- a/internal/proxy/http-proxy.go
+++ b/internal/proxy/http-proxy.go
@@ -71,13 +71,11 @@ func (p *HTTPProxy) Start() error {
 	}
 	p.logger.Info("Access log", zap.Bool("enabled", p.EnableAccessLog))
 
-	mux := &http.ServeMux{}
-	mux.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) {
+	p.httpServer.Handler = http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
 		if !p.HandleHTTPValidation(writer, request) {
 			p.httpReverseProxy.ServeHTTP(writer, request)
 		}
 	})
-	p.httpServer.Handler = mux
 	p.httpServer.IdleTimeout = p.IdleTimeout
 
 	p.logger.Info("Http builtin reverse proxy start")
diff --git a/internal/proxy/http-proxy_test.go b/internal/proxy/http-proxy_test.go
index 62e47b38..1bdcc792 100644
--- a/internal/proxy/http-proxy_test.go
+++ b/internal/proxy/http-proxy_test.go
@@ -10,11 +10,13 @@ import (
 	"net/url"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/gojuno/minimock/v3"
-
 	"github.com/maxatome/go-testdeep"
+	"github.com/rekby/fixenv"
 	zc "github.com/rekby/zapcontext"
+	"golang.org/x/xerrors"
 
 	"github.com/rekby/lets-proxy2/internal/th"
 )
@@ -141,3 +143,60 @@ func TestNewHttpProxy(t *testing.T) {
 	td.CmpNoError(err)
 	td.CmpDeeply(res, []byte{3, 4})
 }
+
+func TestNoDoubleSlashredirectIssue177(t *testing.T) {
+	e, _, flush := th.NewEnv(t)
+	defer flush()
+
+	_, addr := httpProxy(e, th.HttpQuery(e))
+
+	client := http.Client{
+		CheckRedirect: func(req *http.Request, via []*http.Request) error {
+			return http.ErrUseLastResponse
+		},
+	}
+	resp, err := client.Get(addr + "/test//")
+	e.CmpNoError(err)
+
+	body, err := ioutil.ReadAll(resp.Body)
+	e.CmpNoError(err)
+	e.CmpNoError(resp.Body.Close())
+
+	e.Cmp(string(body), "/test//")
+}
+
+func httpProxy(e *th.Env, dst string) (*HTTPProxy, string) {
+	var proxy *HTTPProxy
+	var addr string
+	e.Cache(dst,
+		&fixenv.FixtureOptions{
+			CleanupFunc: func() {
+				_ = proxy.Close()
+			},
+		}, func() (res interface{}, err error) {
+			dstURL, err := url.Parse(dst)
+			if err != nil {
+				return nil, xerrors.Errorf("failed parse dst url %q: %%w", dst, err)
+			}
+			listener := th.TcpListener(e)
+			addr = "http://" + listener.Addr().String()
+			proxy = NewHTTPProxy(e.Ctx, listener)
+			proxy.Director = NewDirectorChain(
+				DirectorHost(dstURL.Host),
+				DirectorSetScheme(dstURL.Scheme),
+			)
+			errChan := make(chan error, 1)
+
+			go func() { errChan <- proxy.Start() }()
+
+			select {
+			case proxyStartErr := <-errChan:
+				err = proxyStartErr
+			case <-time.After(time.Millisecond * 10):
+				// pass
+			}
+
+			return proxy, err
+		})
+	return proxy, addr
+}
diff --git a/internal/th/fixenv.go b/internal/th/fixenv.go
index cbcbc4b0..3d787980 100644
--- a/internal/th/fixenv.go
+++ b/internal/th/fixenv.go
@@ -11,7 +11,7 @@ import (
 )
 
 type Env struct {
-	ctx context.Context
+	Ctx context.Context
 	*fixenv.EnvT
 	TD
 }
@@ -22,7 +22,7 @@ func NewEnv(t *testing.T) (env *Env, ctx context.Context, cancel func()) {
 	tWrap := &testWrapper{T: td}
 	env = &Env{
 		EnvT: fixenv.NewEnv(tWrap),
-		ctx:  ctx,
+		Ctx:  ctx,
 		TD:   TD{T: td},
 	}
 	tWrap.Cleanup(ctxCancel)
diff --git a/internal/th/fixtures.go b/internal/th/fixtures.go
index cda7e130..6c0c6ef0 100644
--- a/internal/th/fixtures.go
+++ b/internal/th/fixtures.go
@@ -2,11 +2,46 @@ package th
 
 import (
 	"io/ioutil"
+	"net"
+	"net/http"
+	"net/http/httptest"
 	"os"
 
 	"github.com/rekby/fixenv"
 )
 
+func HttpQuery(e fixenv.Env) string {
+	var server *httptest.Server
+	return e.Cache(nil,
+		&fixenv.FixtureOptions{
+			CleanupFunc: func() {
+				server.Close()
+			},
+		}, func() (res interface{}, err error) {
+			server = httptest.NewServer(http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
+				u := *request.URL
+				u.Scheme = ""
+				u.Host = ""
+				_, _ = writer.Write([]byte(u.String()))
+			}))
+			return server.URL, nil
+		}).(string)
+}
+
+func TcpListener(e fixenv.Env) *net.TCPListener {
+	var listener *net.TCPListener
+
+	return e.Cache(nil,
+		&fixenv.FixtureOptions{
+			CleanupFunc: func() {
+				_ = listener.Close()
+			}},
+		func() (res interface{}, err error) {
+			listener, err = net.ListenTCP("tcp", &net.TCPAddr{IP: net.IPv4(127, 0, 0, 1)})
+			return listener, err
+		}).(*net.TCPListener)
+}
+
 func TmpDir(e fixenv.Env) string {
 	var dirPath string
 	return e.Cache(nil, &fixenv.FixtureOptions{CleanupFunc: func() {