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Source file src/net/http/client_test.go

Documentation: net/http

  // Copyright 2009 The Go Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style
  // license that can be found in the LICENSE file.
  
  // Tests for client.go
  
  package http_test
  
  import (
  	"bytes"
  	"context"
  	"crypto/tls"
  	"encoding/base64"
  	"errors"
  	"fmt"
  	"io"
  	"io/ioutil"
  	"log"
  	"net"
  	. "net/http"
  	"net/http/cookiejar"
  	"net/http/httptest"
  	"net/url"
  	"reflect"
  	"strconv"
  	"strings"
  	"sync"
  	"sync/atomic"
  	"testing"
  	"time"
  )
  
  var robotsTxtHandler = HandlerFunc(func(w ResponseWriter, r *Request) {
  	w.Header().Set("Last-Modified", "sometime")
  	fmt.Fprintf(w, "User-agent: go\nDisallow: /something/")
  })
  
  // pedanticReadAll works like ioutil.ReadAll but additionally
  // verifies that r obeys the documented io.Reader contract.
  func pedanticReadAll(r io.Reader) (b []byte, err error) {
  	var bufa [64]byte
  	buf := bufa[:]
  	for {
  		n, err := r.Read(buf)
  		if n == 0 && err == nil {
  			return nil, fmt.Errorf("Read: n=0 with err=nil")
  		}
  		b = append(b, buf[:n]...)
  		if err == io.EOF {
  			n, err := r.Read(buf)
  			if n != 0 || err != io.EOF {
  				return nil, fmt.Errorf("Read: n=%d err=%#v after EOF", n, err)
  			}
  			return b, nil
  		}
  		if err != nil {
  			return b, err
  		}
  	}
  }
  
  type chanWriter chan string
  
  func (w chanWriter) Write(p []byte) (n int, err error) {
  	w <- string(p)
  	return len(p), nil
  }
  
  func TestClient(t *testing.T) {
  	setParallel(t)
  	defer afterTest(t)
  	ts := httptest.NewServer(robotsTxtHandler)
  	defer ts.Close()
  
  	c := ts.Client()
  	r, err := c.Get(ts.URL)
  	var b []byte
  	if err == nil {
  		b, err = pedanticReadAll(r.Body)
  		r.Body.Close()
  	}
  	if err != nil {
  		t.Error(err)
  	} else if s := string(b); !strings.HasPrefix(s, "User-agent:") {
  		t.Errorf("Incorrect page body (did not begin with User-agent): %q", s)
  	}
  }
  
  func TestClientHead_h1(t *testing.T) { testClientHead(t, h1Mode) }
  func TestClientHead_h2(t *testing.T) { testClientHead(t, h2Mode) }
  
  func testClientHead(t *testing.T, h2 bool) {
  	defer afterTest(t)
  	cst := newClientServerTest(t, h2, robotsTxtHandler)
  	defer cst.close()
  
  	r, err := cst.c.Head(cst.ts.URL)
  	if err != nil {
  		t.Fatal(err)
  	}
  	if _, ok := r.Header["Last-Modified"]; !ok {
  		t.Error("Last-Modified header not found.")
  	}
  }
  
  type recordingTransport struct {
  	req *Request
  }
  
  func (t *recordingTransport) RoundTrip(req *Request) (resp *Response, err error) {
  	t.req = req
  	return nil, errors.New("dummy impl")
  }
  
  func TestGetRequestFormat(t *testing.T) {
  	setParallel(t)
  	defer afterTest(t)
  	tr := &recordingTransport{}
  	client := &Client{Transport: tr}
  	url := "http://dummy.faketld/"
  	client.Get(url) // Note: doesn't hit network
  	if tr.req.Method != "GET" {
  		t.Errorf("expected method %q; got %q", "GET", tr.req.Method)
  	}
  	if tr.req.URL.String() != url {
  		t.Errorf("expected URL %q; got %q", url, tr.req.URL.String())
  	}
  	if tr.req.Header == nil {
  		t.Errorf("expected non-nil request Header")
  	}
  }
  
  func TestPostRequestFormat(t *testing.T) {
  	defer afterTest(t)
  	tr := &recordingTransport{}
  	client := &Client{Transport: tr}
  
  	url := "http://dummy.faketld/"
  	json := `{"key":"value"}`
  	b := strings.NewReader(json)
  	client.Post(url, "application/json", b) // Note: doesn't hit network
  
  	if tr.req.Method != "POST" {
  		t.Errorf("got method %q, want %q", tr.req.Method, "POST")
  	}
  	if tr.req.URL.String() != url {
  		t.Errorf("got URL %q, want %q", tr.req.URL.String(), url)
  	}
  	if tr.req.Header == nil {
  		t.Fatalf("expected non-nil request Header")
  	}
  	if tr.req.Close {
  		t.Error("got Close true, want false")
  	}
  	if g, e := tr.req.ContentLength, int64(len(json)); g != e {
  		t.Errorf("got ContentLength %d, want %d", g, e)
  	}
  }
  
  func TestPostFormRequestFormat(t *testing.T) {
  	defer afterTest(t)
  	tr := &recordingTransport{}
  	client := &Client{Transport: tr}
  
  	urlStr := "http://dummy.faketld/"
  	form := make(url.Values)
  	form.Set("foo", "bar")
  	form.Add("foo", "bar2")
  	form.Set("bar", "baz")
  	client.PostForm(urlStr, form) // Note: doesn't hit network
  
  	if tr.req.Method != "POST" {
  		t.Errorf("got method %q, want %q", tr.req.Method, "POST")
  	}
  	if tr.req.URL.String() != urlStr {
  		t.Errorf("got URL %q, want %q", tr.req.URL.String(), urlStr)
  	}
  	if tr.req.Header == nil {
  		t.Fatalf("expected non-nil request Header")
  	}
  	if g, e := tr.req.Header.Get("Content-Type"), "application/x-www-form-urlencoded"; g != e {
  		t.Errorf("got Content-Type %q, want %q", g, e)
  	}
  	if tr.req.Close {
  		t.Error("got Close true, want false")
  	}
  	// Depending on map iteration, body can be either of these.
  	expectedBody := "foo=bar&foo=bar2&bar=baz"
  	expectedBody1 := "bar=baz&foo=bar&foo=bar2"
  	if g, e := tr.req.ContentLength, int64(len(expectedBody)); g != e {
  		t.Errorf("got ContentLength %d, want %d", g, e)
  	}
  	bodyb, err := ioutil.ReadAll(tr.req.Body)
  	if err != nil {
  		t.Fatalf("ReadAll on req.Body: %v", err)
  	}
  	if g := string(bodyb); g != expectedBody && g != expectedBody1 {
  		t.Errorf("got body %q, want %q or %q", g, expectedBody, expectedBody1)
  	}
  }
  
  func TestClientRedirects(t *testing.T) {
  	setParallel(t)
  	defer afterTest(t)
  	var ts *httptest.Server
  	ts = httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  		n, _ := strconv.Atoi(r.FormValue("n"))
  		// Test Referer header. (7 is arbitrary position to test at)
  		if n == 7 {
  			if g, e := r.Referer(), ts.URL+"/?n=6"; e != g {
  				t.Errorf("on request ?n=7, expected referer of %q; got %q", e, g)
  			}
  		}
  		if n < 15 {
  			Redirect(w, r, fmt.Sprintf("/?n=%d", n+1), StatusTemporaryRedirect)
  			return
  		}
  		fmt.Fprintf(w, "n=%d", n)
  	}))
  	defer ts.Close()
  
  	c := ts.Client()
  	_, err := c.Get(ts.URL)
  	if e, g := "Get /?n=10: stopped after 10 redirects", fmt.Sprintf("%v", err); e != g {
  		t.Errorf("with default client Get, expected error %q, got %q", e, g)
  	}
  
  	// HEAD request should also have the ability to follow redirects.
  	_, err = c.Head(ts.URL)
  	if e, g := "Head /?n=10: stopped after 10 redirects", fmt.Sprintf("%v", err); e != g {
  		t.Errorf("with default client Head, expected error %q, got %q", e, g)
  	}
  
  	// Do should also follow redirects.
  	greq, _ := NewRequest("GET", ts.URL, nil)
  	_, err = c.Do(greq)
  	if e, g := "Get /?n=10: stopped after 10 redirects", fmt.Sprintf("%v", err); e != g {
  		t.Errorf("with default client Do, expected error %q, got %q", e, g)
  	}
  
  	// Requests with an empty Method should also redirect (Issue 12705)
  	greq.Method = ""
  	_, err = c.Do(greq)
  	if e, g := "Get /?n=10: stopped after 10 redirects", fmt.Sprintf("%v", err); e != g {
  		t.Errorf("with default client Do and empty Method, expected error %q, got %q", e, g)
  	}
  
  	var checkErr error
  	var lastVia []*Request
  	var lastReq *Request
  	c.CheckRedirect = func(req *Request, via []*Request) error {
  		lastReq = req
  		lastVia = via
  		return checkErr
  	}
  	res, err := c.Get(ts.URL)
  	if err != nil {
  		t.Fatalf("Get error: %v", err)
  	}
  	res.Body.Close()
  	finalUrl := res.Request.URL.String()
  	if e, g := "<nil>", fmt.Sprintf("%v", err); e != g {
  		t.Errorf("with custom client, expected error %q, got %q", e, g)
  	}
  	if !strings.HasSuffix(finalUrl, "/?n=15") {
  		t.Errorf("expected final url to end in /?n=15; got url %q", finalUrl)
  	}
  	if e, g := 15, len(lastVia); e != g {
  		t.Errorf("expected lastVia to have contained %d elements; got %d", e, g)
  	}
  
  	// Test that Request.Cancel is propagated between requests (Issue 14053)
  	creq, _ := NewRequest("HEAD", ts.URL, nil)
  	cancel := make(chan struct{})
  	creq.Cancel = cancel
  	if _, err := c.Do(creq); err != nil {
  		t.Fatal(err)
  	}
  	if lastReq == nil {
  		t.Fatal("didn't see redirect")
  	}
  	if lastReq.Cancel != cancel {
  		t.Errorf("expected lastReq to have the cancel channel set on the initial req")
  	}
  
  	checkErr = errors.New("no redirects allowed")
  	res, err = c.Get(ts.URL)
  	if urlError, ok := err.(*url.Error); !ok || urlError.Err != checkErr {
  		t.Errorf("with redirects forbidden, expected a *url.Error with our 'no redirects allowed' error inside; got %#v (%q)", err, err)
  	}
  	if res == nil {
  		t.Fatalf("Expected a non-nil Response on CheckRedirect failure (https://golang.org/issue/3795)")
  	}
  	res.Body.Close()
  	if res.Header.Get("Location") == "" {
  		t.Errorf("no Location header in Response")
  	}
  }
  
  // Tests that Client redirects' contexts are derived from the original request's context.
  func TestClientRedirectContext(t *testing.T) {
  	setParallel(t)
  	defer afterTest(t)
  	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  		Redirect(w, r, "/", StatusTemporaryRedirect)
  	}))
  	defer ts.Close()
  
  	ctx, cancel := context.WithCancel(context.Background())
  	c := ts.Client()
  	c.CheckRedirect = func(req *Request, via []*Request) error {
  		cancel()
  		select {
  		case <-req.Context().Done():
  			return nil
  		case <-time.After(5 * time.Second):
  			return errors.New("redirected request's context never expired after root request canceled")
  		}
  	}
  	req, _ := NewRequest("GET", ts.URL, nil)
  	req = req.WithContext(ctx)
  	_, err := c.Do(req)
  	ue, ok := err.(*url.Error)
  	if !ok {
  		t.Fatalf("got error %T; want *url.Error", err)
  	}
  	if ue.Err != context.Canceled {
  		t.Errorf("url.Error.Err = %v; want %v", ue.Err, context.Canceled)
  	}
  }
  
  type redirectTest struct {
  	suffix       string
  	want         int // response code
  	redirectBody string
  }
  
  func TestPostRedirects(t *testing.T) {
  	postRedirectTests := []redirectTest{
  		{"/", 200, "first"},
  		{"/?code=301&next=302", 200, "c301"},
  		{"/?code=302&next=302", 200, "c302"},
  		{"/?code=303&next=301", 200, "c303wc301"}, // Issue 9348
  		{"/?code=304", 304, "c304"},
  		{"/?code=305", 305, "c305"},
  		{"/?code=307&next=303,308,302", 200, "c307"},
  		{"/?code=308&next=302,301", 200, "c308"},
  		{"/?code=404", 404, "c404"},
  	}
  
  	wantSegments := []string{
  		`POST / "first"`,
  		`POST /?code=301&next=302 "c301"`,
  		`GET /?code=302 ""`,
  		`GET / ""`,
  		`POST /?code=302&next=302 "c302"`,
  		`GET /?code=302 ""`,
  		`GET / ""`,
  		`POST /?code=303&next=301 "c303wc301"`,
  		`GET /?code=301 ""`,
  		`GET / ""`,
  		`POST /?code=304 "c304"`,
  		`POST /?code=305 "c305"`,
  		`POST /?code=307&next=303,308,302 "c307"`,
  		`POST /?code=303&next=308,302 "c307"`,
  		`GET /?code=308&next=302 ""`,
  		`GET /?code=302 "c307"`,
  		`GET / ""`,
  		`POST /?code=308&next=302,301 "c308"`,
  		`POST /?code=302&next=301 "c308"`,
  		`GET /?code=301 ""`,
  		`GET / ""`,
  		`POST /?code=404 "c404"`,
  	}
  	want := strings.Join(wantSegments, "\n")
  	testRedirectsByMethod(t, "POST", postRedirectTests, want)
  }
  
  func TestDeleteRedirects(t *testing.T) {
  	deleteRedirectTests := []redirectTest{
  		{"/", 200, "first"},
  		{"/?code=301&next=302,308", 200, "c301"},
  		{"/?code=302&next=302", 200, "c302"},
  		{"/?code=303", 200, "c303"},
  		{"/?code=307&next=301,308,303,302,304", 304, "c307"},
  		{"/?code=308&next=307", 200, "c308"},
  		{"/?code=404", 404, "c404"},
  	}
  
  	wantSegments := []string{
  		`DELETE / "first"`,
  		`DELETE /?code=301&next=302,308 "c301"`,
  		`GET /?code=302&next=308 ""`,
  		`GET /?code=308 ""`,
  		`GET / "c301"`,
  		`DELETE /?code=302&next=302 "c302"`,
  		`GET /?code=302 ""`,
  		`GET / ""`,
  		`DELETE /?code=303 "c303"`,
  		`GET / ""`,
  		`DELETE /?code=307&next=301,308,303,302,304 "c307"`,
  		`DELETE /?code=301&next=308,303,302,304 "c307"`,
  		`GET /?code=308&next=303,302,304 ""`,
  		`GET /?code=303&next=302,304 "c307"`,
  		`GET /?code=302&next=304 ""`,
  		`GET /?code=304 ""`,
  		`DELETE /?code=308&next=307 "c308"`,
  		`DELETE /?code=307 "c308"`,
  		`DELETE / "c308"`,
  		`DELETE /?code=404 "c404"`,
  	}
  	want := strings.Join(wantSegments, "\n")
  	testRedirectsByMethod(t, "DELETE", deleteRedirectTests, want)
  }
  
  func testRedirectsByMethod(t *testing.T, method string, table []redirectTest, want string) {
  	defer afterTest(t)
  	var log struct {
  		sync.Mutex
  		bytes.Buffer
  	}
  	var ts *httptest.Server
  	ts = httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  		log.Lock()
  		slurp, _ := ioutil.ReadAll(r.Body)
  		fmt.Fprintf(&log.Buffer, "%s %s %q", r.Method, r.RequestURI, slurp)
  		if cl := r.Header.Get("Content-Length"); r.Method == "GET" && len(slurp) == 0 && (r.ContentLength != 0 || cl != "") {
  			fmt.Fprintf(&log.Buffer, " (but with body=%T, content-length = %v, %q)", r.Body, r.ContentLength, cl)
  		}
  		log.WriteByte('\n')
  		log.Unlock()
  		urlQuery := r.URL.Query()
  		if v := urlQuery.Get("code"); v != "" {
  			location := ts.URL
  			if final := urlQuery.Get("next"); final != "" {
  				splits := strings.Split(final, ",")
  				first, rest := splits[0], splits[1:]
  				location = fmt.Sprintf("%s?code=%s", location, first)
  				if len(rest) > 0 {
  					location = fmt.Sprintf("%s&next=%s", location, strings.Join(rest, ","))
  				}
  			}
  			code, _ := strconv.Atoi(v)
  			if code/100 == 3 {
  				w.Header().Set("Location", location)
  			}
  			w.WriteHeader(code)
  		}
  	}))
  	defer ts.Close()
  
  	c := ts.Client()
  	for _, tt := range table {
  		content := tt.redirectBody
  		req, _ := NewRequest(method, ts.URL+tt.suffix, strings.NewReader(content))
  		req.GetBody = func() (io.ReadCloser, error) { return ioutil.NopCloser(strings.NewReader(content)), nil }
  		res, err := c.Do(req)
  
  		if err != nil {
  			t.Fatal(err)
  		}
  		if res.StatusCode != tt.want {
  			t.Errorf("POST %s: status code = %d; want %d", tt.suffix, res.StatusCode, tt.want)
  		}
  	}
  	log.Lock()
  	got := log.String()
  	log.Unlock()
  
  	got = strings.TrimSpace(got)
  	want = strings.TrimSpace(want)
  
  	if got != want {
  		got, want, lines := removeCommonLines(got, want)
  		t.Errorf("Log differs after %d common lines.\n\nGot:\n%s\n\nWant:\n%s\n", lines, got, want)
  	}
  }
  
  func removeCommonLines(a, b string) (asuffix, bsuffix string, commonLines int) {
  	for {
  		nl := strings.IndexByte(a, '\n')
  		if nl < 0 {
  			return a, b, commonLines
  		}
  		line := a[:nl+1]
  		if !strings.HasPrefix(b, line) {
  			return a, b, commonLines
  		}
  		commonLines++
  		a = a[len(line):]
  		b = b[len(line):]
  	}
  }
  
  func TestClientRedirectUseResponse(t *testing.T) {
  	setParallel(t)
  	defer afterTest(t)
  	const body = "Hello, world."
  	var ts *httptest.Server
  	ts = httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  		if strings.Contains(r.URL.Path, "/other") {
  			io.WriteString(w, "wrong body")
  		} else {
  			w.Header().Set("Location", ts.URL+"/other")
  			w.WriteHeader(StatusFound)
  			io.WriteString(w, body)
  		}
  	}))
  	defer ts.Close()
  
  	c := ts.Client()
  	c.CheckRedirect = func(req *Request, via []*Request) error {
  		if req.Response == nil {
  			t.Error("expected non-nil Request.Response")
  		}
  		return ErrUseLastResponse
  	}
  	res, err := c.Get(ts.URL)
  	if err != nil {
  		t.Fatal(err)
  	}
  	if res.StatusCode != StatusFound {
  		t.Errorf("status = %d; want %d", res.StatusCode, StatusFound)
  	}
  	defer res.Body.Close()
  	slurp, err := ioutil.ReadAll(res.Body)
  	if err != nil {
  		t.Fatal(err)
  	}
  	if string(slurp) != body {
  		t.Errorf("body = %q; want %q", slurp, body)
  	}
  }
  
  // Issue 17773: don't follow a 308 (or 307) if the response doesn't
  // have a Location header.
  func TestClientRedirect308NoLocation(t *testing.T) {
  	setParallel(t)
  	defer afterTest(t)
  	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  		w.Header().Set("Foo", "Bar")
  		w.WriteHeader(308)
  	}))
  	defer ts.Close()
  	c := ts.Client()
  	res, err := c.Get(ts.URL)
  	if err != nil {
  		t.Fatal(err)
  	}
  	res.Body.Close()
  	if res.StatusCode != 308 {
  		t.Errorf("status = %d; want %d", res.StatusCode, 308)
  	}
  	if got := res.Header.Get("Foo"); got != "Bar" {
  		t.Errorf("Foo header = %q; want Bar", got)
  	}
  }
  
  // Don't follow a 307/308 if we can't resent the request body.
  func TestClientRedirect308NoGetBody(t *testing.T) {
  	setParallel(t)
  	defer afterTest(t)
  	const fakeURL = "https://localhost:1234/" // won't be hit
  	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  		w.Header().Set("Location", fakeURL)
  		w.WriteHeader(308)
  	}))
  	defer ts.Close()
  	req, err := NewRequest("POST", ts.URL, strings.NewReader("some body"))
  	if err != nil {
  		t.Fatal(err)
  	}
  	c := ts.Client()
  	req.GetBody = nil // so it can't rewind.
  	res, err := c.Do(req)
  	if err != nil {
  		t.Fatal(err)
  	}
  	res.Body.Close()
  	if res.StatusCode != 308 {
  		t.Errorf("status = %d; want %d", res.StatusCode, 308)
  	}
  	if got := res.Header.Get("Location"); got != fakeURL {
  		t.Errorf("Location header = %q; want %q", got, fakeURL)
  	}
  }
  
  var expectedCookies = []*Cookie{
  	{Name: "ChocolateChip", Value: "tasty"},
  	{Name: "First", Value: "Hit"},
  	{Name: "Second", Value: "Hit"},
  }
  
  var echoCookiesRedirectHandler = HandlerFunc(func(w ResponseWriter, r *Request) {
  	for _, cookie := range r.Cookies() {
  		SetCookie(w, cookie)
  	}
  	if r.URL.Path == "/" {
  		SetCookie(w, expectedCookies[1])
  		Redirect(w, r, "/second", StatusMovedPermanently)
  	} else {
  		SetCookie(w, expectedCookies[2])
  		w.Write([]byte("hello"))
  	}
  })
  
  func TestClientSendsCookieFromJar(t *testing.T) {
  	defer afterTest(t)
  	tr := &recordingTransport{}
  	client := &Client{Transport: tr}
  	client.Jar = &TestJar{perURL: make(map[string][]*Cookie)}
  	us := "http://dummy.faketld/"
  	u, _ := url.Parse(us)
  	client.Jar.SetCookies(u, expectedCookies)
  
  	client.Get(us) // Note: doesn't hit network
  	matchReturnedCookies(t, expectedCookies, tr.req.Cookies())
  
  	client.Head(us) // Note: doesn't hit network
  	matchReturnedCookies(t, expectedCookies, tr.req.Cookies())
  
  	client.Post(us, "text/plain", strings.NewReader("body")) // Note: doesn't hit network
  	matchReturnedCookies(t, expectedCookies, tr.req.Cookies())
  
  	client.PostForm(us, url.Values{}) // Note: doesn't hit network
  	matchReturnedCookies(t, expectedCookies, tr.req.Cookies())
  
  	req, _ := NewRequest("GET", us, nil)
  	client.Do(req) // Note: doesn't hit network
  	matchReturnedCookies(t, expectedCookies, tr.req.Cookies())
  
  	req, _ = NewRequest("POST", us, nil)
  	client.Do(req) // Note: doesn't hit network
  	matchReturnedCookies(t, expectedCookies, tr.req.Cookies())
  }
  
  // Just enough correctness for our redirect tests. Uses the URL.Host as the
  // scope of all cookies.
  type TestJar struct {
  	m      sync.Mutex
  	perURL map[string][]*Cookie
  }
  
  func (j *TestJar) SetCookies(u *url.URL, cookies []*Cookie) {
  	j.m.Lock()
  	defer j.m.Unlock()
  	if j.perURL == nil {
  		j.perURL = make(map[string][]*Cookie)
  	}
  	j.perURL[u.Host] = cookies
  }
  
  func (j *TestJar) Cookies(u *url.URL) []*Cookie {
  	j.m.Lock()
  	defer j.m.Unlock()
  	return j.perURL[u.Host]
  }
  
  func TestRedirectCookiesJar(t *testing.T) {
  	setParallel(t)
  	defer afterTest(t)
  	var ts *httptest.Server
  	ts = httptest.NewServer(echoCookiesRedirectHandler)
  	defer ts.Close()
  	c := ts.Client()
  	c.Jar = new(TestJar)
  	u, _ := url.Parse(ts.URL)
  	c.Jar.SetCookies(u, []*Cookie{expectedCookies[0]})
  	resp, err := c.Get(ts.URL)
  	if err != nil {
  		t.Fatalf("Get: %v", err)
  	}
  	resp.Body.Close()
  	matchReturnedCookies(t, expectedCookies, resp.Cookies())
  }
  
  func matchReturnedCookies(t *testing.T, expected, given []*Cookie) {
  	if len(given) != len(expected) {
  		t.Logf("Received cookies: %v", given)
  		t.Errorf("Expected %d cookies, got %d", len(expected), len(given))
  	}
  	for _, ec := range expected {
  		foundC := false
  		for _, c := range given {
  			if ec.Name == c.Name && ec.Value == c.Value {
  				foundC = true
  				break
  			}
  		}
  		if !foundC {
  			t.Errorf("Missing cookie %v", ec)
  		}
  	}
  }
  
  func TestJarCalls(t *testing.T) {
  	defer afterTest(t)
  	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  		pathSuffix := r.RequestURI[1:]
  		if r.RequestURI == "/nosetcookie" {
  			return // don't set cookies for this path
  		}
  		SetCookie(w, &Cookie{Name: "name" + pathSuffix, Value: "val" + pathSuffix})
  		if r.RequestURI == "/" {
  			Redirect(w, r, "http://secondhost.fake/secondpath", 302)
  		}
  	}))
  	defer ts.Close()
  	jar := new(RecordingJar)
  	c := ts.Client()
  	c.Jar = jar
  	c.Transport.(*Transport).Dial = func(_ string, _ string) (net.Conn, error) {
  		return net.Dial("tcp", ts.Listener.Addr().String())
  	}
  	_, err := c.Get("http://firsthost.fake/")
  	if err != nil {
  		t.Fatal(err)
  	}
  	_, err = c.Get("http://firsthost.fake/nosetcookie")
  	if err != nil {
  		t.Fatal(err)
  	}
  	got := jar.log.String()
  	want := `Cookies("http://firsthost.fake/")
  SetCookie("http://firsthost.fake/", [name=val])
  Cookies("http://secondhost.fake/secondpath")
  SetCookie("http://secondhost.fake/secondpath", [namesecondpath=valsecondpath])
  Cookies("http://firsthost.fake/nosetcookie")
  `
  	if got != want {
  		t.Errorf("Got Jar calls:\n%s\nWant:\n%s", got, want)
  	}
  }
  
  // RecordingJar keeps a log of calls made to it, without
  // tracking any cookies.
  type RecordingJar struct {
  	mu  sync.Mutex
  	log bytes.Buffer
  }
  
  func (j *RecordingJar) SetCookies(u *url.URL, cookies []*Cookie) {
  	j.logf("SetCookie(%q, %v)\n", u, cookies)
  }
  
  func (j *RecordingJar) Cookies(u *url.URL) []*Cookie {
  	j.logf("Cookies(%q)\n", u)
  	return nil
  }
  
  func (j *RecordingJar) logf(format string, args ...interface{}) {
  	j.mu.Lock()
  	defer j.mu.Unlock()
  	fmt.Fprintf(&j.log, format, args...)
  }
  
  func TestStreamingGet_h1(t *testing.T) { testStreamingGet(t, h1Mode) }
  func TestStreamingGet_h2(t *testing.T) { testStreamingGet(t, h2Mode) }
  
  func testStreamingGet(t *testing.T, h2 bool) {
  	defer afterTest(t)
  	say := make(chan string)
  	cst := newClientServerTest(t, h2, HandlerFunc(func(w ResponseWriter, r *Request) {
  		w.(Flusher).Flush()
  		for str := range say {
  			w.Write([]byte(str))
  			w.(Flusher).Flush()
  		}
  	}))
  	defer cst.close()
  
  	c := cst.c
  	res, err := c.Get(cst.ts.URL)
  	if err != nil {
  		t.Fatal(err)
  	}
  	var buf [10]byte
  	for _, str := range []string{"i", "am", "also", "known", "as", "comet"} {
  		say <- str
  		n, err := io.ReadFull(res.Body, buf[0:len(str)])
  		if err != nil {
  			t.Fatalf("ReadFull on %q: %v", str, err)
  		}
  		if n != len(str) {
  			t.Fatalf("Receiving %q, only read %d bytes", str, n)
  		}
  		got := string(buf[0:n])
  		if got != str {
  			t.Fatalf("Expected %q, got %q", str, got)
  		}
  	}
  	close(say)
  	_, err = io.ReadFull(res.Body, buf[0:1])
  	if err != io.EOF {
  		t.Fatalf("at end expected EOF, got %v", err)
  	}
  }
  
  type writeCountingConn struct {
  	net.Conn
  	count *int
  }
  
  func (c *writeCountingConn) Write(p []byte) (int, error) {
  	*c.count++
  	return c.Conn.Write(p)
  }
  
  // TestClientWrites verifies that client requests are buffered and we
  // don't send a TCP packet per line of the http request + body.
  func TestClientWrites(t *testing.T) {
  	defer afterTest(t)
  	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  	}))
  	defer ts.Close()
  
  	writes := 0
  	dialer := func(netz string, addr string) (net.Conn, error) {
  		c, err := net.Dial(netz, addr)
  		if err == nil {
  			c = &writeCountingConn{c, &writes}
  		}
  		return c, err
  	}
  	c := ts.Client()
  	c.Transport.(*Transport).Dial = dialer
  
  	_, err := c.Get(ts.URL)
  	if err != nil {
  		t.Fatal(err)
  	}
  	if writes != 1 {
  		t.Errorf("Get request did %d Write calls, want 1", writes)
  	}
  
  	writes = 0
  	_, err = c.PostForm(ts.URL, url.Values{"foo": {"bar"}})
  	if err != nil {
  		t.Fatal(err)
  	}
  	if writes != 1 {
  		t.Errorf("Post request did %d Write calls, want 1", writes)
  	}
  }
  
  func TestClientInsecureTransport(t *testing.T) {
  	setParallel(t)
  	defer afterTest(t)
  	ts := httptest.NewTLSServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  		w.Write([]byte("Hello"))
  	}))
  	errc := make(chanWriter, 10) // but only expecting 1
  	ts.Config.ErrorLog = log.New(errc, "", 0)
  	defer ts.Close()
  
  	// TODO(bradfitz): add tests for skipping hostname checks too?
  	// would require a new cert for testing, and probably
  	// redundant with these tests.
  	c := ts.Client()
  	for _, insecure := range []bool{true, false} {
  		c.Transport.(*Transport).TLSClientConfig = &tls.Config{
  			InsecureSkipVerify: insecure,
  		}
  		res, err := c.Get(ts.URL)
  		if (err == nil) != insecure {
  			t.Errorf("insecure=%v: got unexpected err=%v", insecure, err)
  		}
  		if res != nil {
  			res.Body.Close()
  		}
  	}
  
  	select {
  	case v := <-errc:
  		if !strings.Contains(v, "TLS handshake error") {
  			t.Errorf("expected an error log message containing 'TLS handshake error'; got %q", v)
  		}
  	case <-time.After(5 * time.Second):
  		t.Errorf("timeout waiting for logged error")
  	}
  
  }
  
  func TestClientErrorWithRequestURI(t *testing.T) {
  	defer afterTest(t)
  	req, _ := NewRequest("GET", "http://localhost:1234/", nil)
  	req.RequestURI = "/this/field/is/illegal/and/should/error/"
  	_, err := DefaultClient.Do(req)
  	if err == nil {
  		t.Fatalf("expected an error")
  	}
  	if !strings.Contains(err.Error(), "RequestURI") {
  		t.Errorf("wanted error mentioning RequestURI; got error: %v", err)
  	}
  }
  
  func TestClientWithCorrectTLSServerName(t *testing.T) {
  	defer afterTest(t)
  
  	const serverName = "example.com"
  	ts := httptest.NewTLSServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  		if r.TLS.ServerName != serverName {
  			t.Errorf("expected client to set ServerName %q, got: %q", serverName, r.TLS.ServerName)
  		}
  	}))
  	defer ts.Close()
  
  	c := ts.Client()
  	c.Transport.(*Transport).TLSClientConfig.ServerName = serverName
  	if _, err := c.Get(ts.URL); err != nil {
  		t.Fatalf("expected successful TLS connection, got error: %v", err)
  	}
  }
  
  func TestClientWithIncorrectTLSServerName(t *testing.T) {
  	defer afterTest(t)
  	ts := httptest.NewTLSServer(HandlerFunc(func(w ResponseWriter, r *Request) {}))
  	defer ts.Close()
  	errc := make(chanWriter, 10) // but only expecting 1
  	ts.Config.ErrorLog = log.New(errc, "", 0)
  
  	c := ts.Client()
  	c.Transport.(*Transport).TLSClientConfig.ServerName = "badserver"
  	_, err := c.Get(ts.URL)
  	if err == nil {
  		t.Fatalf("expected an error")
  	}
  	if !strings.Contains(err.Error(), "127.0.0.1") || !strings.Contains(err.Error(), "badserver") {
  		t.Errorf("wanted error mentioning 127.0.0.1 and badserver; got error: %v", err)
  	}
  	select {
  	case v := <-errc:
  		if !strings.Contains(v, "TLS handshake error") {
  			t.Errorf("expected an error log message containing 'TLS handshake error'; got %q", v)
  		}
  	case <-time.After(5 * time.Second):
  		t.Errorf("timeout waiting for logged error")
  	}
  }
  
  // Test for golang.org/issue/5829; the Transport should respect TLSClientConfig.ServerName
  // when not empty.
  //
  // tls.Config.ServerName (non-empty, set to "example.com") takes
  // precedence over "some-other-host.tld" which previously incorrectly
  // took precedence. We don't actually connect to (or even resolve)
  // "some-other-host.tld", though, because of the Transport.Dial hook.
  //
  // The httptest.Server has a cert with "example.com" as its name.
  func TestTransportUsesTLSConfigServerName(t *testing.T) {
  	defer afterTest(t)
  	ts := httptest.NewTLSServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  		w.Write([]byte("Hello"))
  	}))
  	defer ts.Close()
  
  	c := ts.Client()
  	tr := c.Transport.(*Transport)
  	tr.TLSClientConfig.ServerName = "example.com" // one of httptest's Server cert names
  	tr.Dial = func(netw, addr string) (net.Conn, error) {
  		return net.Dial(netw, ts.Listener.Addr().String())
  	}
  	res, err := c.Get("https://some-other-host.tld/")
  	if err != nil {
  		t.Fatal(err)
  	}
  	res.Body.Close()
  }
  
  func TestResponseSetsTLSConnectionState(t *testing.T) {
  	defer afterTest(t)
  	ts := httptest.NewTLSServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  		w.Write([]byte("Hello"))
  	}))
  	defer ts.Close()
  
  	c := ts.Client()
  	tr := c.Transport.(*Transport)
  	tr.TLSClientConfig.CipherSuites = []uint16{tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA}
  	tr.Dial = func(netw, addr string) (net.Conn, error) {
  		return net.Dial(netw, ts.Listener.Addr().String())
  	}
  	res, err := c.Get("https://example.com/")
  	if err != nil {
  		t.Fatal(err)
  	}
  	defer res.Body.Close()
  	if res.TLS == nil {
  		t.Fatal("Response didn't set TLS Connection State.")
  	}
  	if got, want := res.TLS.CipherSuite, tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA; got != want {
  		t.Errorf("TLS Cipher Suite = %d; want %d", got, want)
  	}
  }
  
  // Check that an HTTPS client can interpret a particular TLS error
  // to determine that the server is speaking HTTP.
  // See golang.org/issue/11111.
  func TestHTTPSClientDetectsHTTPServer(t *testing.T) {
  	defer afterTest(t)
  	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {}))
  	ts.Config.ErrorLog = quietLog
  	defer ts.Close()
  
  	_, err := Get(strings.Replace(ts.URL, "http", "https", 1))
  	if got := err.Error(); !strings.Contains(got, "HTTP response to HTTPS client") {
  		t.Fatalf("error = %q; want error indicating HTTP response to HTTPS request", got)
  	}
  }
  
  // Verify Response.ContentLength is populated. https://golang.org/issue/4126
  func TestClientHeadContentLength_h1(t *testing.T) {
  	testClientHeadContentLength(t, h1Mode)
  }
  
  func TestClientHeadContentLength_h2(t *testing.T) {
  	testClientHeadContentLength(t, h2Mode)
  }
  
  func testClientHeadContentLength(t *testing.T, h2 bool) {
  	defer afterTest(t)
  	cst := newClientServerTest(t, h2, HandlerFunc(func(w ResponseWriter, r *Request) {
  		if v := r.FormValue("cl"); v != "" {
  			w.Header().Set("Content-Length", v)
  		}
  	}))
  	defer cst.close()
  	tests := []struct {
  		suffix string
  		want   int64
  	}{
  		{"/?cl=1234", 1234},
  		{"/?cl=0", 0},
  		{"", -1},
  	}
  	for _, tt := range tests {
  		req, _ := NewRequest("HEAD", cst.ts.URL+tt.suffix, nil)
  		res, err := cst.c.Do(req)
  		if err != nil {
  			t.Fatal(err)
  		}
  		if res.ContentLength != tt.want {
  			t.Errorf("Content-Length = %d; want %d", res.ContentLength, tt.want)
  		}
  		bs, err := ioutil.ReadAll(res.Body)
  		if err != nil {
  			t.Fatal(err)
  		}
  		if len(bs) != 0 {
  			t.Errorf("Unexpected content: %q", bs)
  		}
  	}
  }
  
  func TestEmptyPasswordAuth(t *testing.T) {
  	setParallel(t)
  	defer afterTest(t)
  	gopher := "gopher"
  	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  		auth := r.Header.Get("Authorization")
  		if strings.HasPrefix(auth, "Basic ") {
  			encoded := auth[6:]
  			decoded, err := base64.StdEncoding.DecodeString(encoded)
  			if err != nil {
  				t.Fatal(err)
  			}
  			expected := gopher + ":"
  			s := string(decoded)
  			if expected != s {
  				t.Errorf("Invalid Authorization header. Got %q, wanted %q", s, expected)
  			}
  		} else {
  			t.Errorf("Invalid auth %q", auth)
  		}
  	}))
  	defer ts.Close()
  	req, err := NewRequest("GET", ts.URL, nil)
  	if err != nil {
  		t.Fatal(err)
  	}
  	req.URL.User = url.User(gopher)
  	c := ts.Client()
  	resp, err := c.Do(req)
  	if err != nil {
  		t.Fatal(err)
  	}
  	defer resp.Body.Close()
  }
  
  func TestBasicAuth(t *testing.T) {
  	defer afterTest(t)
  	tr := &recordingTransport{}
  	client := &Client{Transport: tr}
  
  	url := "http://My%20User:My%20Pass@dummy.faketld/"
  	expected := "My User:My Pass"
  	client.Get(url)
  
  	if tr.req.Method != "GET" {
  		t.Errorf("got method %q, want %q", tr.req.Method, "GET")
  	}
  	if tr.req.URL.String() != url {
  		t.Errorf("got URL %q, want %q", tr.req.URL.String(), url)
  	}
  	if tr.req.Header == nil {
  		t.Fatalf("expected non-nil request Header")
  	}
  	auth := tr.req.Header.Get("Authorization")
  	if strings.HasPrefix(auth, "Basic ") {
  		encoded := auth[6:]
  		decoded, err := base64.StdEncoding.DecodeString(encoded)
  		if err != nil {
  			t.Fatal(err)
  		}
  		s := string(decoded)
  		if expected != s {
  			t.Errorf("Invalid Authorization header. Got %q, wanted %q", s, expected)
  		}
  	} else {
  		t.Errorf("Invalid auth %q", auth)
  	}
  }
  
  func TestBasicAuthHeadersPreserved(t *testing.T) {
  	defer afterTest(t)
  	tr := &recordingTransport{}
  	client := &Client{Transport: tr}
  
  	// If Authorization header is provided, username in URL should not override it
  	url := "http://My%20User@dummy.faketld/"
  	req, err := NewRequest("GET", url, nil)
  	if err != nil {
  		t.Fatal(err)
  	}
  	req.SetBasicAuth("My User", "My Pass")
  	expected := "My User:My Pass"
  	client.Do(req)
  
  	if tr.req.Method != "GET" {
  		t.Errorf("got method %q, want %q", tr.req.Method, "GET")
  	}
  	if tr.req.URL.String() != url {
  		t.Errorf("got URL %q, want %q", tr.req.URL.String(), url)
  	}
  	if tr.req.Header == nil {
  		t.Fatalf("expected non-nil request Header")
  	}
  	auth := tr.req.Header.Get("Authorization")
  	if strings.HasPrefix(auth, "Basic ") {
  		encoded := auth[6:]
  		decoded, err := base64.StdEncoding.DecodeString(encoded)
  		if err != nil {
  			t.Fatal(err)
  		}
  		s := string(decoded)
  		if expected != s {
  			t.Errorf("Invalid Authorization header. Got %q, wanted %q", s, expected)
  		}
  	} else {
  		t.Errorf("Invalid auth %q", auth)
  	}
  
  }
  
  func TestClientTimeout_h1(t *testing.T) { testClientTimeout(t, h1Mode) }
  func TestClientTimeout_h2(t *testing.T) { testClientTimeout(t, h2Mode) }
  
  func testClientTimeout(t *testing.T, h2 bool) {
  	setParallel(t)
  	defer afterTest(t)
  	testDone := make(chan struct{}) // closed in defer below
  
  	sawRoot := make(chan bool, 1)
  	sawSlow := make(chan bool, 1)
  	cst := newClientServerTest(t, h2, HandlerFunc(func(w ResponseWriter, r *Request) {
  		if r.URL.Path == "/" {
  			sawRoot <- true
  			Redirect(w, r, "/slow", StatusFound)
  			return
  		}
  		if r.URL.Path == "/slow" {
  			sawSlow <- true
  			w.Write([]byte("Hello"))
  			w.(Flusher).Flush()
  			<-testDone
  			return
  		}
  	}))
  	defer cst.close()
  	defer close(testDone) // before cst.close, to unblock /slow handler
  
  	// 200ms should be long enough to get a normal request (the /
  	// handler), but not so long that it makes the test slow.
  	const timeout = 200 * time.Millisecond
  	cst.c.Timeout = timeout
  
  	res, err := cst.c.Get(cst.ts.URL)
  	if err != nil {
  		if strings.Contains(err.Error(), "Client.Timeout") {
  			t.Skipf("host too slow to get fast resource in %v", timeout)
  		}
  		t.Fatal(err)
  	}
  
  	select {
  	case <-sawRoot:
  		// good.
  	default:
  		t.Fatal("handler never got / request")
  	}
  
  	select {
  	case <-sawSlow:
  		// good.
  	default:
  		t.Fatal("handler never got /slow request")
  	}
  
  	errc := make(chan error, 1)
  	go func() {
  		_, err := ioutil.ReadAll(res.Body)
  		errc <- err
  		res.Body.Close()
  	}()
  
  	const failTime = 5 * time.Second
  	select {
  	case err := <-errc:
  		if err == nil {
  			t.Fatal("expected error from ReadAll")
  		}
  		ne, ok := err.(net.Error)
  		if !ok {
  			t.Errorf("error value from ReadAll was %T; expected some net.Error", err)
  		} else if !ne.Timeout() {
  			t.Errorf("net.Error.Timeout = false; want true")
  		}
  		if got := ne.Error(); !strings.Contains(got, "Client.Timeout exceeded") {
  			t.Errorf("error string = %q; missing timeout substring", got)
  		}
  	case <-time.After(failTime):
  		t.Errorf("timeout after %v waiting for timeout of %v", failTime, timeout)
  	}
  }
  
  func TestClientTimeout_Headers_h1(t *testing.T) { testClientTimeout_Headers(t, h1Mode) }
  func TestClientTimeout_Headers_h2(t *testing.T) { testClientTimeout_Headers(t, h2Mode) }
  
  // Client.Timeout firing before getting to the body
  func testClientTimeout_Headers(t *testing.T, h2 bool) {
  	setParallel(t)
  	defer afterTest(t)
  	donec := make(chan bool, 1)
  	cst := newClientServerTest(t, h2, HandlerFunc(func(w ResponseWriter, r *Request) {
  		<-donec
  	}))
  	defer cst.close()
  	// Note that we use a channel send here and not a close.
  	// The race detector doesn't know that we're waiting for a timeout
  	// and thinks that the waitgroup inside httptest.Server is added to concurrently
  	// with us closing it. If we timed out immediately, we could close the testserver
  	// before we entered the handler. We're not timing out immediately and there's
  	// no way we would be done before we entered the handler, but the race detector
  	// doesn't know this, so synchronize explicitly.
  	defer func() { donec <- true }()
  
  	cst.c.Timeout = 5 * time.Millisecond
  	res, err := cst.c.Get(cst.ts.URL)
  	if err == nil {
  		res.Body.Close()
  		t.Fatal("got response from Get; expected error")
  	}
  	if _, ok := err.(*url.Error); !ok {
  		t.Fatalf("Got error of type %T; want *url.Error", err)
  	}
  	ne, ok := err.(net.Error)
  	if !ok {
  		t.Fatalf("Got error of type %T; want some net.Error", err)
  	}
  	if !ne.Timeout() {
  		t.Error("net.Error.Timeout = false; want true")
  	}
  	if got := ne.Error(); !strings.Contains(got, "Client.Timeout exceeded") {
  		t.Errorf("error string = %q; missing timeout substring", got)
  	}
  }
  
  // Issue 16094: if Client.Timeout is set but not hit, a Timeout error shouldn't be
  // returned.
  func TestClientTimeoutCancel(t *testing.T) {
  	setParallel(t)
  	defer afterTest(t)
  
  	testDone := make(chan struct{})
  	ctx, cancel := context.WithCancel(context.Background())
  
  	cst := newClientServerTest(t, h1Mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  		w.(Flusher).Flush()
  		<-testDone
  	}))
  	defer cst.close()
  	defer close(testDone)
  
  	cst.c.Timeout = 1 * time.Hour
  	req, _ := NewRequest("GET", cst.ts.URL, nil)
  	req.Cancel = ctx.Done()
  	res, err := cst.c.Do(req)
  	if err != nil {
  		t.Fatal(err)
  	}
  	cancel()
  	_, err = io.Copy(ioutil.Discard, res.Body)
  	if err != ExportErrRequestCanceled {
  		t.Fatalf("error = %v; want errRequestCanceled", err)
  	}
  }
  
  func TestClientRedirectEatsBody_h1(t *testing.T) { testClientRedirectEatsBody(t, h1Mode) }
  func TestClientRedirectEatsBody_h2(t *testing.T) { testClientRedirectEatsBody(t, h2Mode) }
  func testClientRedirectEatsBody(t *testing.T, h2 bool) {
  	setParallel(t)
  	defer afterTest(t)
  	saw := make(chan string, 2)
  	cst := newClientServerTest(t, h2, HandlerFunc(func(w ResponseWriter, r *Request) {
  		saw <- r.RemoteAddr
  		if r.URL.Path == "/" {
  			Redirect(w, r, "/foo", StatusFound) // which includes a body
  		}
  	}))
  	defer cst.close()
  
  	res, err := cst.c.Get(cst.ts.URL)
  	if err != nil {
  		t.Fatal(err)
  	}
  	_, err = ioutil.ReadAll(res.Body)
  	res.Body.Close()
  	if err != nil {
  		t.Fatal(err)
  	}
  
  	var first string
  	select {
  	case first = <-saw:
  	default:
  		t.Fatal("server didn't see a request")
  	}
  
  	var second string
  	select {
  	case second = <-saw:
  	default:
  		t.Fatal("server didn't see a second request")
  	}
  
  	if first != second {
  		t.Fatal("server saw different client ports before & after the redirect")
  	}
  }
  
  // eofReaderFunc is an io.Reader that runs itself, and then returns io.EOF.
  type eofReaderFunc func()
  
  func (f eofReaderFunc) Read(p []byte) (n int, err error) {
  	f()
  	return 0, io.EOF
  }
  
  func TestReferer(t *testing.T) {
  	tests := []struct {
  		lastReq, newReq string // from -> to URLs
  		want            string
  	}{
  		// don't send user:
  		{"http://gopher@test.com", "http://link.com", "http://test.com"},
  		{"https://gopher@test.com", "https://link.com", "https://test.com"},
  
  		// don't send a user and password:
  		{"http://gopher:go@test.com", "http://link.com", "http://test.com"},
  		{"https://gopher:go@test.com", "https://link.com", "https://test.com"},
  
  		// nothing to do:
  		{"http://test.com", "http://link.com", "http://test.com"},
  		{"https://test.com", "https://link.com", "https://test.com"},
  
  		// https to http doesn't send a referer:
  		{"https://test.com", "http://link.com", ""},
  		{"https://gopher:go@test.com", "http://link.com", ""},
  	}
  	for _, tt := range tests {
  		l, err := url.Parse(tt.lastReq)
  		if err != nil {
  			t.Fatal(err)
  		}
  		n, err := url.Parse(tt.newReq)
  		if err != nil {
  			t.Fatal(err)
  		}
  		r := ExportRefererForURL(l, n)
  		if r != tt.want {
  			t.Errorf("refererForURL(%q, %q) = %q; want %q", tt.lastReq, tt.newReq, r, tt.want)
  		}
  	}
  }
  
  // issue15577Tripper returns a Response with a redirect response
  // header and doesn't populate its Response.Request field.
  type issue15577Tripper struct{}
  
  func (issue15577Tripper) RoundTrip(*Request) (*Response, error) {
  	resp := &Response{
  		StatusCode: 303,
  		Header:     map[string][]string{"Location": {"http://www.example.com/"}},
  		Body:       ioutil.NopCloser(strings.NewReader("")),
  	}
  	return resp, nil
  }
  
  // Issue 15577: don't assume the roundtripper's response populates its Request field.
  func TestClientRedirectResponseWithoutRequest(t *testing.T) {
  	c := &Client{
  		CheckRedirect: func(*Request, []*Request) error { return fmt.Errorf("no redirects!") },
  		Transport:     issue15577Tripper{},
  	}
  	// Check that this doesn't crash:
  	c.Get("http://dummy.tld")
  }
  
  // Issue 4800: copy (some) headers when Client follows a redirect
  func TestClientCopyHeadersOnRedirect(t *testing.T) {
  	const (
  		ua   = "some-agent/1.2"
  		xfoo = "foo-val"
  	)
  	var ts2URL string
  	ts1 := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  		want := Header{
  			"User-Agent":      []string{ua},
  			"X-Foo":           []string{xfoo},
  			"Referer":         []string{ts2URL},
  			"Accept-Encoding": []string{"gzip"},
  		}
  		if !reflect.DeepEqual(r.Header, want) {
  			t.Errorf("Request.Header = %#v; want %#v", r.Header, want)
  		}
  		if t.Failed() {
  			w.Header().Set("Result", "got errors")
  		} else {
  			w.Header().Set("Result", "ok")
  		}
  	}))
  	defer ts1.Close()
  	ts2 := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  		Redirect(w, r, ts1.URL, StatusFound)
  	}))
  	defer ts2.Close()
  	ts2URL = ts2.URL
  
  	c := ts1.Client()
  	c.CheckRedirect = func(r *Request, via []*Request) error {
  		want := Header{
  			"User-Agent": []string{ua},
  			"X-Foo":      []string{xfoo},
  			"Referer":    []string{ts2URL},
  		}
  		if !reflect.DeepEqual(r.Header, want) {
  			t.Errorf("CheckRedirect Request.Header = %#v; want %#v", r.Header, want)
  		}
  		return nil
  	}
  
  	req, _ := NewRequest("GET", ts2.URL, nil)
  	req.Header.Add("User-Agent", ua)
  	req.Header.Add("X-Foo", xfoo)
  	req.Header.Add("Cookie", "foo=bar")
  	req.Header.Add("Authorization", "secretpassword")
  	res, err := c.Do(req)
  	if err != nil {
  		t.Fatal(err)
  	}
  	defer res.Body.Close()
  	if res.StatusCode != 200 {
  		t.Fatal(res.Status)
  	}
  	if got := res.Header.Get("Result"); got != "ok" {
  		t.Errorf("result = %q; want ok", got)
  	}
  }
  
  // Issue 17494: cookies should be altered when Client follows redirects.
  func TestClientAltersCookiesOnRedirect(t *testing.T) {
  	cookieMap := func(cs []*Cookie) map[string][]string {
  		m := make(map[string][]string)
  		for _, c := range cs {
  			m[c.Name] = append(m[c.Name], c.Value)
  		}
  		return m
  	}
  
  	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  		var want map[string][]string
  		got := cookieMap(r.Cookies())
  
  		c, _ := r.Cookie("Cycle")
  		switch c.Value {
  		case "0":
  			want = map[string][]string{
  				"Cookie1": {"OldValue1a", "OldValue1b"},
  				"Cookie2": {"OldValue2"},
  				"Cookie3": {"OldValue3a", "OldValue3b"},
  				"Cookie4": {"OldValue4"},
  				"Cycle":   {"0"},
  			}
  			SetCookie(w, &Cookie{Name: "Cycle", Value: "1", Path: "/"})
  			SetCookie(w, &Cookie{Name: "Cookie2", Path: "/", MaxAge: -1}) // Delete cookie from Header
  			Redirect(w, r, "/", StatusFound)
  		case "1":
  			want = map[string][]string{
  				"Cookie1": {"OldValue1a", "OldValue1b"},
  				"Cookie3": {"OldValue3a", "OldValue3b"},
  				"Cookie4": {"OldValue4"},
  				"Cycle":   {"1"},
  			}
  			SetCookie(w, &Cookie{Name: "Cycle", Value: "2", Path: "/"})
  			SetCookie(w, &Cookie{Name: "Cookie3", Value: "NewValue3", Path: "/"}) // Modify cookie in Header
  			SetCookie(w, &Cookie{Name: "Cookie4", Value: "NewValue4", Path: "/"}) // Modify cookie in Jar
  			Redirect(w, r, "/", StatusFound)
  		case "2":
  			want = map[string][]string{
  				"Cookie1": {"OldValue1a", "OldValue1b"},
  				"Cookie3": {"NewValue3"},
  				"Cookie4": {"NewValue4"},
  				"Cycle":   {"2"},
  			}
  			SetCookie(w, &Cookie{Name: "Cycle", Value: "3", Path: "/"})
  			SetCookie(w, &Cookie{Name: "Cookie5", Value: "NewValue5", Path: "/"}) // Insert cookie into Jar
  			Redirect(w, r, "/", StatusFound)
  		case "3":
  			want = map[string][]string{
  				"Cookie1": {"OldValue1a", "OldValue1b"},
  				"Cookie3": {"NewValue3"},
  				"Cookie4": {"NewValue4"},
  				"Cookie5": {"NewValue5"},
  				"Cycle":   {"3"},
  			}
  			// Don't redirect to ensure the loop ends.
  		default:
  			t.Errorf("unexpected redirect cycle")
  			return
  		}
  
  		if !reflect.DeepEqual(got, want) {
  			t.Errorf("redirect %s, Cookie = %v, want %v", c.Value, got, want)
  		}
  	}))
  	defer ts.Close()
  
  	jar, _ := cookiejar.New(nil)
  	c := ts.Client()
  	c.Jar = jar
  
  	u, _ := url.Parse(ts.URL)
  	req, _ := NewRequest("GET", ts.URL, nil)
  	req.AddCookie(&Cookie{Name: "Cookie1", Value: "OldValue1a"})
  	req.AddCookie(&Cookie{Name: "Cookie1", Value: "OldValue1b"})
  	req.AddCookie(&Cookie{Name: "Cookie2", Value: "OldValue2"})
  	req.AddCookie(&Cookie{Name: "Cookie3", Value: "OldValue3a"})
  	req.AddCookie(&Cookie{Name: "Cookie3", Value: "OldValue3b"})
  	jar.SetCookies(u, []*Cookie{{Name: "Cookie4", Value: "OldValue4", Path: "/"}})
  	jar.SetCookies(u, []*Cookie{{Name: "Cycle", Value: "0", Path: "/"}})
  	res, err := c.Do(req)
  	if err != nil {
  		t.Fatal(err)
  	}
  	defer res.Body.Close()
  	if res.StatusCode != 200 {
  		t.Fatal(res.Status)
  	}
  }
  
  // Part of Issue 4800
  func TestShouldCopyHeaderOnRedirect(t *testing.T) {
  	tests := []struct {
  		header     string
  		initialURL string
  		destURL    string
  		want       bool
  	}{
  		{"User-Agent", "http://foo.com/", "http://bar.com/", true},
  		{"X-Foo", "http://foo.com/", "http://bar.com/", true},
  
  		// Sensitive headers:
  		{"cookie", "http://foo.com/", "http://bar.com/", false},
  		{"cookie2", "http://foo.com/", "http://bar.com/", false},
  		{"authorization", "http://foo.com/", "http://bar.com/", false},
  		{"www-authenticate", "http://foo.com/", "http://bar.com/", false},
  
  		// But subdomains should work:
  		{"www-authenticate", "http://foo.com/", "http://foo.com/", true},
  		{"www-authenticate", "http://foo.com/", "http://sub.foo.com/", true},
  		{"www-authenticate", "http://foo.com/", "http://notfoo.com/", false},
  		// TODO(bradfitz): make this test work, once issue 16142 is fixed:
  		// {"www-authenticate", "http://foo.com:80/", "http://foo.com/", true},
  	}
  	for i, tt := range tests {
  		u0, err := url.Parse(tt.initialURL)
  		if err != nil {
  			t.Errorf("%d. initial URL %q parse error: %v", i, tt.initialURL, err)
  			continue
  		}
  		u1, err := url.Parse(tt.destURL)
  		if err != nil {
  			t.Errorf("%d. dest URL %q parse error: %v", i, tt.destURL, err)
  			continue
  		}
  		got := Export_shouldCopyHeaderOnRedirect(tt.header, u0, u1)
  		if got != tt.want {
  			t.Errorf("%d. shouldCopyHeaderOnRedirect(%q, %q => %q) = %v; want %v",
  				i, tt.header, tt.initialURL, tt.destURL, got, tt.want)
  		}
  	}
  }
  
  func TestClientRedirectTypes(t *testing.T) {
  	setParallel(t)
  	defer afterTest(t)
  
  	tests := [...]struct {
  		method       string
  		serverStatus int
  		wantMethod   string // desired subsequent client method
  	}{
  		0: {method: "POST", serverStatus: 301, wantMethod: "GET"},
  		1: {method: "POST", serverStatus: 302, wantMethod: "GET"},
  		2: {method: "POST", serverStatus: 303, wantMethod: "GET"},
  		3: {method: "POST", serverStatus: 307, wantMethod: "POST"},
  		4: {method: "POST", serverStatus: 308, wantMethod: "POST"},
  
  		5: {method: "HEAD", serverStatus: 301, wantMethod: "HEAD"},
  		6: {method: "HEAD", serverStatus: 302, wantMethod: "HEAD"},
  		7: {method: "HEAD", serverStatus: 303, wantMethod: "HEAD"},
  		8: {method: "HEAD", serverStatus: 307, wantMethod: "HEAD"},
  		9: {method: "HEAD", serverStatus: 308, wantMethod: "HEAD"},
  
  		10: {method: "GET", serverStatus: 301, wantMethod: "GET"},
  		11: {method: "GET", serverStatus: 302, wantMethod: "GET"},
  		12: {method: "GET", serverStatus: 303, wantMethod: "GET"},
  		13: {method: "GET", serverStatus: 307, wantMethod: "GET"},
  		14: {method: "GET", serverStatus: 308, wantMethod: "GET"},
  
  		15: {method: "DELETE", serverStatus: 301, wantMethod: "GET"},
  		16: {method: "DELETE", serverStatus: 302, wantMethod: "GET"},
  		17: {method: "DELETE", serverStatus: 303, wantMethod: "GET"},
  		18: {method: "DELETE", serverStatus: 307, wantMethod: "DELETE"},
  		19: {method: "DELETE", serverStatus: 308, wantMethod: "DELETE"},
  
  		20: {method: "PUT", serverStatus: 301, wantMethod: "GET"},
  		21: {method: "PUT", serverStatus: 302, wantMethod: "GET"},
  		22: {method: "PUT", serverStatus: 303, wantMethod: "GET"},
  		23: {method: "PUT", serverStatus: 307, wantMethod: "PUT"},
  		24: {method: "PUT", serverStatus: 308, wantMethod: "PUT"},
  
  		25: {method: "MADEUPMETHOD", serverStatus: 301, wantMethod: "GET"},
  		26: {method: "MADEUPMETHOD", serverStatus: 302, wantMethod: "GET"},
  		27: {method: "MADEUPMETHOD", serverStatus: 303, wantMethod: "GET"},
  		28: {method: "MADEUPMETHOD", serverStatus: 307, wantMethod: "MADEUPMETHOD"},
  		29: {method: "MADEUPMETHOD", serverStatus: 308, wantMethod: "MADEUPMETHOD"},
  	}
  
  	handlerc := make(chan HandlerFunc, 1)
  
  	ts := httptest.NewServer(HandlerFunc(func(rw ResponseWriter, req *Request) {
  		h := <-handlerc
  		h(rw, req)
  	}))
  	defer ts.Close()
  
  	c := ts.Client()
  	for i, tt := range tests {
  		handlerc <- func(w ResponseWriter, r *Request) {
  			w.Header().Set("Location", ts.URL)
  			w.WriteHeader(tt.serverStatus)
  		}
  
  		req, err := NewRequest(tt.method, ts.URL, nil)
  		if err != nil {
  			t.Errorf("#%d: NewRequest: %v", i, err)
  			continue
  		}
  
  		c.CheckRedirect = func(req *Request, via []*Request) error {
  			if got, want := req.Method, tt.wantMethod; got != want {
  				return fmt.Errorf("#%d: got next method %q; want %q", i, got, want)
  			}
  			handlerc <- func(rw ResponseWriter, req *Request) {
  				// TODO: Check that the body is valid when we do 307 and 308 support
  			}
  			return nil
  		}
  
  		res, err := c.Do(req)
  		if err != nil {
  			t.Errorf("#%d: Response: %v", i, err)
  			continue
  		}
  
  		res.Body.Close()
  	}
  }
  
  // issue18239Body is an io.ReadCloser for TestTransportBodyReadError.
  // Its Read returns readErr and increments *readCalls atomically.
  // Its Close returns nil and increments *closeCalls atomically.
  type issue18239Body struct {
  	readCalls  *int32
  	closeCalls *int32
  	readErr    error
  }
  
  func (b issue18239Body) Read([]byte) (int, error) {
  	atomic.AddInt32(b.readCalls, 1)
  	return 0, b.readErr
  }
  
  func (b issue18239Body) Close() error {
  	atomic.AddInt32(b.closeCalls, 1)
  	return nil
  }
  
  // Issue 18239: make sure the Transport doesn't retry requests with bodies
  // if Request.GetBody is not defined.
  func TestTransportBodyReadError(t *testing.T) {
  	setParallel(t)
  	defer afterTest(t)
  	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
  		if r.URL.Path == "/ping" {
  			return
  		}
  		buf := make([]byte, 1)
  		n, err := r.Body.Read(buf)
  		w.Header().Set("X-Body-Read", fmt.Sprintf("%v, %v", n, err))
  	}))
  	defer ts.Close()
  	c := ts.Client()
  	tr := c.Transport.(*Transport)
  
  	// Do one initial successful request to create an idle TCP connection
  	// for the subsequent request to reuse. (The Transport only retries
  	// requests on reused connections.)
  	res, err := c.Get(ts.URL + "/ping")
  	if err != nil {
  		t.Fatal(err)
  	}
  	res.Body.Close()
  
  	var readCallsAtomic int32
  	var closeCallsAtomic int32 // atomic
  	someErr := errors.New("some body read error")
  	body := issue18239Body{&readCallsAtomic, &closeCallsAtomic, someErr}
  
  	req, err := NewRequest("POST", ts.URL, body)
  	if err != nil {
  		t.Fatal(err)
  	}
  	req = req.WithT(t)
  	_, err = tr.RoundTrip(req)
  	if err != someErr {
  		t.Errorf("Got error: %v; want Request.Body read error: %v", err, someErr)
  	}
  
  	// And verify that our Body wasn't used multiple times, which
  	// would indicate retries. (as it buggily was during part of
  	// Go 1.8's dev cycle)
  	readCalls := atomic.LoadInt32(&readCallsAtomic)
  	closeCalls := atomic.LoadInt32(&closeCallsAtomic)
  	if readCalls != 1 {
  		t.Errorf("read calls = %d; want 1", readCalls)
  	}
  	if closeCalls != 1 {
  		t.Errorf("close calls = %d; want 1", closeCalls)
  	}
  }
  

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