// Copyright 2010 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. package http import ( "bufio" "bytes" "compress/gzip" "crypto/rand" "fmt" "go/ast" "io" "io/ioutil" "net/http/internal" "net/url" "reflect" "regexp" "strings" "testing" ) type respTest struct { Raw string Resp Response Body string } func dummyReq(method string) *Request { return &Request{Method: method} } func dummyReq11(method string) *Request { return &Request{Method: method, Proto: "HTTP/1.1", ProtoMajor: 1, ProtoMinor: 1} } var respTests = []respTest{ // Unchunked response without Content-Length. { "HTTP/1.0 200 OK\r\n" + "Connection: close\r\n" + "\r\n" + "Body here\n", Response{ Status: "200 OK", StatusCode: 200, Proto: "HTTP/1.0", ProtoMajor: 1, ProtoMinor: 0, Request: dummyReq("GET"), Header: Header{ "Connection": {"close"}, // TODO(rsc): Delete? }, Close: true, ContentLength: -1, }, "Body here\n", }, // Unchunked HTTP/1.1 response without Content-Length or // Connection headers. { "HTTP/1.1 200 OK\r\n" + "\r\n" + "Body here\n", Response{ Status: "200 OK", StatusCode: 200, Proto: "HTTP/1.1", ProtoMajor: 1, ProtoMinor: 1, Header: Header{}, Request: dummyReq("GET"), Close: true, ContentLength: -1, }, "Body here\n", }, // Unchunked HTTP/1.1 204 response without Content-Length. { "HTTP/1.1 204 No Content\r\n" + "\r\n" + "Body should not be read!\n", Response{ Status: "204 No Content", StatusCode: 204, Proto: "HTTP/1.1", ProtoMajor: 1, ProtoMinor: 1, Header: Header{}, Request: dummyReq("GET"), Close: false, ContentLength: 0, }, "", }, // Unchunked response with Content-Length. { "HTTP/1.0 200 OK\r\n" + "Content-Length: 10\r\n" + "Connection: close\r\n" + "\r\n" + "Body here\n", Response{ Status: "200 OK", StatusCode: 200, Proto: "HTTP/1.0", ProtoMajor: 1, ProtoMinor: 0, Request: dummyReq("GET"), Header: Header{ "Connection": {"close"}, "Content-Length": {"10"}, }, Close: true, ContentLength: 10, }, "Body here\n", }, // Chunked response without Content-Length. { "HTTP/1.1 200 OK\r\n" + "Transfer-Encoding: chunked\r\n" + "\r\n" + "0a\r\n" + "Body here\n\r\n" + "09\r\n" + "continued\r\n" + "0\r\n" + "\r\n", Response{ Status: "200 OK", StatusCode: 200, Proto: "HTTP/1.1", ProtoMajor: 1, ProtoMinor: 1, Request: dummyReq("GET"), Header: Header{}, Close: false, ContentLength: -1, TransferEncoding: []string{"chunked"}, }, "Body here\ncontinued", }, // Chunked response with Content-Length. { "HTTP/1.1 200 OK\r\n" + "Transfer-Encoding: chunked\r\n" + "Content-Length: 10\r\n" + "\r\n" + "0a\r\n" + "Body here\n\r\n" + "0\r\n" + "\r\n", Response{ Status: "200 OK", StatusCode: 200, Proto: "HTTP/1.1", ProtoMajor: 1, ProtoMinor: 1, Request: dummyReq("GET"), Header: Header{}, Close: false, ContentLength: -1, TransferEncoding: []string{"chunked"}, }, "Body here\n", }, // Chunked response in response to a HEAD request { "HTTP/1.1 200 OK\r\n" + "Transfer-Encoding: chunked\r\n" + "\r\n", Response{ Status: "200 OK", StatusCode: 200, Proto: "HTTP/1.1", ProtoMajor: 1, ProtoMinor: 1, Request: dummyReq("HEAD"), Header: Header{}, TransferEncoding: []string{"chunked"}, Close: false, ContentLength: -1, }, "", }, // Content-Length in response to a HEAD request { "HTTP/1.0 200 OK\r\n" + "Content-Length: 256\r\n" + "\r\n", Response{ Status: "200 OK", StatusCode: 200, Proto: "HTTP/1.0", ProtoMajor: 1, ProtoMinor: 0, Request: dummyReq("HEAD"), Header: Header{"Content-Length": {"256"}}, TransferEncoding: nil, Close: true, ContentLength: 256, }, "", }, // Content-Length in response to a HEAD request with HTTP/1.1 { "HTTP/1.1 200 OK\r\n" + "Content-Length: 256\r\n" + "\r\n", Response{ Status: "200 OK", StatusCode: 200, Proto: "HTTP/1.1", ProtoMajor: 1, ProtoMinor: 1, Request: dummyReq("HEAD"), Header: Header{"Content-Length": {"256"}}, TransferEncoding: nil, Close: false, ContentLength: 256, }, "", }, // No Content-Length or Chunked in response to a HEAD request { "HTTP/1.0 200 OK\r\n" + "\r\n", Response{ Status: "200 OK", StatusCode: 200, Proto: "HTTP/1.0", ProtoMajor: 1, ProtoMinor: 0, Request: dummyReq("HEAD"), Header: Header{}, TransferEncoding: nil, Close: true, ContentLength: -1, }, "", }, // explicit Content-Length of 0. { "HTTP/1.1 200 OK\r\n" + "Content-Length: 0\r\n" + "\r\n", Response{ Status: "200 OK", StatusCode: 200, Proto: "HTTP/1.1", ProtoMajor: 1, ProtoMinor: 1, Request: dummyReq("GET"), Header: Header{ "Content-Length": {"0"}, }, Close: false, ContentLength: 0, }, "", }, // Status line without a Reason-Phrase, but trailing space. // (permitted by RFC 2616) { "HTTP/1.0 303 \r\n\r\n", Response{ Status: "303 ", StatusCode: 303, Proto: "HTTP/1.0", ProtoMajor: 1, ProtoMinor: 0, Request: dummyReq("GET"), Header: Header{}, Close: true, ContentLength: -1, }, "", }, // Status line without a Reason-Phrase, and no trailing space. // (not permitted by RFC 2616, but we'll accept it anyway) { "HTTP/1.0 303\r\n\r\n", Response{ Status: "303", StatusCode: 303, Proto: "HTTP/1.0", ProtoMajor: 1, ProtoMinor: 0, Request: dummyReq("GET"), Header: Header{}, Close: true, ContentLength: -1, }, "", }, // golang.org/issue/4767: don't special-case multipart/byteranges responses { `HTTP/1.1 206 Partial Content Connection: close Content-Type: multipart/byteranges; boundary=18a75608c8f47cef some body`, Response{ Status: "206 Partial Content", StatusCode: 206, Proto: "HTTP/1.1", ProtoMajor: 1, ProtoMinor: 1, Request: dummyReq("GET"), Header: Header{ "Content-Type": []string{"multipart/byteranges; boundary=18a75608c8f47cef"}, }, Close: true, ContentLength: -1, }, "some body", }, // Unchunked response without Content-Length, Request is nil { "HTTP/1.0 200 OK\r\n" + "Connection: close\r\n" + "\r\n" + "Body here\n", Response{ Status: "200 OK", StatusCode: 200, Proto: "HTTP/1.0", ProtoMajor: 1, ProtoMinor: 0, Header: Header{ "Connection": {"close"}, // TODO(rsc): Delete? }, Close: true, ContentLength: -1, }, "Body here\n", }, // 206 Partial Content. golang.org/issue/8923 { "HTTP/1.1 206 Partial Content\r\n" + "Content-Type: text/plain; charset=utf-8\r\n" + "Accept-Ranges: bytes\r\n" + "Content-Range: bytes 0-5/1862\r\n" + "Content-Length: 6\r\n\r\n" + "foobar", Response{ Status: "206 Partial Content", StatusCode: 206, Proto: "HTTP/1.1", ProtoMajor: 1, ProtoMinor: 1, Request: dummyReq("GET"), Header: Header{ "Accept-Ranges": []string{"bytes"}, "Content-Length": []string{"6"}, "Content-Type": []string{"text/plain; charset=utf-8"}, "Content-Range": []string{"bytes 0-5/1862"}, }, ContentLength: 6, }, "foobar", }, // Both keep-alive and close, on the same Connection line. (Issue 8840) { "HTTP/1.1 200 OK\r\n" + "Content-Length: 256\r\n" + "Connection: keep-alive, close\r\n" + "\r\n", Response{ Status: "200 OK", StatusCode: 200, Proto: "HTTP/1.1", ProtoMajor: 1, ProtoMinor: 1, Request: dummyReq("HEAD"), Header: Header{ "Content-Length": {"256"}, }, TransferEncoding: nil, Close: true, ContentLength: 256, }, "", }, // Both keep-alive and close, on different Connection lines. (Issue 8840) { "HTTP/1.1 200 OK\r\n" + "Content-Length: 256\r\n" + "Connection: keep-alive\r\n" + "Connection: close\r\n" + "\r\n", Response{ Status: "200 OK", StatusCode: 200, Proto: "HTTP/1.1", ProtoMajor: 1, ProtoMinor: 1, Request: dummyReq("HEAD"), Header: Header{ "Content-Length": {"256"}, }, TransferEncoding: nil, Close: true, ContentLength: 256, }, "", }, // Issue 12785: HTTP/1.0 response with bogus (to be ignored) Transfer-Encoding. // Without a Content-Length. { "HTTP/1.0 200 OK\r\n" + "Transfer-Encoding: bogus\r\n" + "\r\n" + "Body here\n", Response{ Status: "200 OK", StatusCode: 200, Proto: "HTTP/1.0", ProtoMajor: 1, ProtoMinor: 0, Request: dummyReq("GET"), Header: Header{}, Close: true, ContentLength: -1, }, "Body here\n", }, // Issue 12785: HTTP/1.0 response with bogus (to be ignored) Transfer-Encoding. // With a Content-Length. { "HTTP/1.0 200 OK\r\n" + "Transfer-Encoding: bogus\r\n" + "Content-Length: 10\r\n" + "\r\n" + "Body here\n", Response{ Status: "200 OK", StatusCode: 200, Proto: "HTTP/1.0", ProtoMajor: 1, ProtoMinor: 0, Request: dummyReq("GET"), Header: Header{ "Content-Length": {"10"}, }, Close: true, ContentLength: 10, }, "Body here\n", }, { "HTTP/1.1 200 OK\r\n" + "Content-Encoding: gzip\r\n" + "Content-Length: 23\r\n" + "Connection: keep-alive\r\n" + "Keep-Alive: timeout=7200\r\n\r\n" + "\x1f\x8b\b\x00\x00\x00\x00\x00\x00\x00s\xf3\xf7\a\x00\xab'\xd4\x1a\x03\x00\x00\x00", Response{ Status: "200 OK", StatusCode: 200, Proto: "HTTP/1.1", ProtoMajor: 1, ProtoMinor: 1, Request: dummyReq("GET"), Header: Header{ "Content-Length": {"23"}, "Content-Encoding": {"gzip"}, "Connection": {"keep-alive"}, "Keep-Alive": {"timeout=7200"}, }, Close: false, ContentLength: 23, }, "\x1f\x8b\b\x00\x00\x00\x00\x00\x00\x00s\xf3\xf7\a\x00\xab'\xd4\x1a\x03\x00\x00\x00", }, // Issue 19989: two spaces between HTTP version and status. { "HTTP/1.0 401 Unauthorized\r\n" + "Content-type: text/html\r\n" + "WWW-Authenticate: Basic realm=\"\"\r\n\r\n" + "Your Authentication failed.\r\n", Response{ Status: "401 Unauthorized", StatusCode: 401, Proto: "HTTP/1.0", ProtoMajor: 1, ProtoMinor: 0, Request: dummyReq("GET"), Header: Header{ "Content-Type": {"text/html"}, "Www-Authenticate": {`Basic realm=""`}, }, Close: true, ContentLength: -1, }, "Your Authentication failed.\r\n", }, } // tests successful calls to ReadResponse, and inspects the returned Response. // For error cases, see TestReadResponseErrors below. func TestReadResponse(t *testing.T) { for i, tt := range respTests { resp, err := ReadResponse(bufio.NewReader(strings.NewReader(tt.Raw)), tt.Resp.Request) if err != nil { t.Errorf("#%d: %v", i, err) continue } rbody := resp.Body resp.Body = nil diff(t, fmt.Sprintf("#%d Response", i), resp, &tt.Resp) var bout bytes.Buffer if rbody != nil { _, err = io.Copy(&bout, rbody) if err != nil { t.Errorf("#%d: %v", i, err) continue } rbody.Close() } body := bout.String() if body != tt.Body { t.Errorf("#%d: Body = %q want %q", i, body, tt.Body) } } } func TestWriteResponse(t *testing.T) { for i, tt := range respTests { resp, err := ReadResponse(bufio.NewReader(strings.NewReader(tt.Raw)), tt.Resp.Request) if err != nil { t.Errorf("#%d: %v", i, err) continue } err = resp.Write(ioutil.Discard) if err != nil { t.Errorf("#%d: %v", i, err) continue } } } var readResponseCloseInMiddleTests = []struct { chunked, compressed bool }{ {false, false}, {true, false}, {true, true}, } // TestReadResponseCloseInMiddle tests that closing a body after // reading only part of its contents advances the read to the end of // the request, right up until the next request. func TestReadResponseCloseInMiddle(t *testing.T) { t.Parallel() for _, test := range readResponseCloseInMiddleTests { fatalf := func(format string, args ...interface{}) { args = append([]interface{}{test.chunked, test.compressed}, args...) t.Fatalf("on test chunked=%v, compressed=%v: "+format, args...) } checkErr := func(err error, msg string) { if err == nil { return } fatalf(msg+": %v", err) } var buf bytes.Buffer buf.WriteString("HTTP/1.1 200 OK\r\n") if test.chunked { buf.WriteString("Transfer-Encoding: chunked\r\n") } else { buf.WriteString("Content-Length: 1000000\r\n") } var wr io.Writer = &buf if test.chunked { wr = internal.NewChunkedWriter(wr) } if test.compressed { buf.WriteString("Content-Encoding: gzip\r\n") wr = gzip.NewWriter(wr) } buf.WriteString("\r\n") chunk := bytes.Repeat([]byte{'x'}, 1000) for i := 0; i < 1000; i++ { if test.compressed { // Otherwise this compresses too well. _, err := io.ReadFull(rand.Reader, chunk) checkErr(err, "rand.Reader ReadFull") } wr.Write(chunk) } if test.compressed { err := wr.(*gzip.Writer).Close() checkErr(err, "compressor close") } if test.chunked { buf.WriteString("0\r\n\r\n") } buf.WriteString("Next Request Here") bufr := bufio.NewReader(&buf) resp, err := ReadResponse(bufr, dummyReq("GET")) checkErr(err, "ReadResponse") expectedLength := int64(-1) if !test.chunked { expectedLength = 1000000 } if resp.ContentLength != expectedLength { fatalf("expected response length %d, got %d", expectedLength, resp.ContentLength) } if resp.Body == nil { fatalf("nil body") } if test.compressed { gzReader, err := gzip.NewReader(resp.Body) checkErr(err, "gzip.NewReader") resp.Body = &readerAndCloser{gzReader, resp.Body} } rbuf := make([]byte, 2500) n, err := io.ReadFull(resp.Body, rbuf) checkErr(err, "2500 byte ReadFull") if n != 2500 { fatalf("ReadFull only read %d bytes", n) } if test.compressed == false && !bytes.Equal(bytes.Repeat([]byte{'x'}, 2500), rbuf) { fatalf("ReadFull didn't read 2500 'x'; got %q", string(rbuf)) } resp.Body.Close() rest, err := ioutil.ReadAll(bufr) checkErr(err, "ReadAll on remainder") if e, g := "Next Request Here", string(rest); e != g { g = regexp.MustCompile(`(xx+)`).ReplaceAllStringFunc(g, func(match string) string { return fmt.Sprintf("x(repeated x%d)", len(match)) }) fatalf("remainder = %q, expected %q", g, e) } } } func diff(t *testing.T, prefix string, have, want interface{}) { hv := reflect.ValueOf(have).Elem() wv := reflect.ValueOf(want).Elem() if hv.Type() != wv.Type() { t.Errorf("%s: type mismatch %v want %v", prefix, hv.Type(), wv.Type()) } for i := 0; i < hv.NumField(); i++ { name := hv.Type().Field(i).Name if !ast.IsExported(name) { continue } hf := hv.Field(i).Interface() wf := wv.Field(i).Interface() if !reflect.DeepEqual(hf, wf) { t.Errorf("%s: %s = %v want %v", prefix, name, hf, wf) } } } type responseLocationTest struct { location string // Response's Location header or "" requrl string // Response.Request.URL or "" want string wantErr error } var responseLocationTests = []responseLocationTest{ {"/foo", "http://bar.com/baz", "http://bar.com/foo", nil}, {"http://foo.com/", "http://bar.com/baz", "http://foo.com/", nil}, {"", "http://bar.com/baz", "", ErrNoLocation}, {"/bar", "", "/bar", nil}, } func TestLocationResponse(t *testing.T) { for i, tt := range responseLocationTests { res := new(Response) res.Header = make(Header) res.Header.Set("Location", tt.location) if tt.requrl != "" { res.Request = &Request{} var err error res.Request.URL, err = url.Parse(tt.requrl) if err != nil { t.Fatalf("bad test URL %q: %v", tt.requrl, err) } } got, err := res.Location() if tt.wantErr != nil { if err == nil { t.Errorf("%d. err=nil; want %q", i, tt.wantErr) continue } if g, e := err.Error(), tt.wantErr.Error(); g != e { t.Errorf("%d. err=%q; want %q", i, g, e) continue } continue } if err != nil { t.Errorf("%d. err=%q", i, err) continue } if g, e := got.String(), tt.want; g != e { t.Errorf("%d. Location=%q; want %q", i, g, e) } } } func TestResponseStatusStutter(t *testing.T) { r := &Response{ Status: "123 some status", StatusCode: 123, ProtoMajor: 1, ProtoMinor: 3, } var buf bytes.Buffer r.Write(&buf) if strings.Contains(buf.String(), "123 123") { t.Errorf("stutter in status: %s", buf.String()) } } func TestResponseContentLengthShortBody(t *testing.T) { const shortBody = "Short body, not 123 bytes." br := bufio.NewReader(strings.NewReader("HTTP/1.1 200 OK\r\n" + "Content-Length: 123\r\n" + "\r\n" + shortBody)) res, err := ReadResponse(br, &Request{Method: "GET"}) if err != nil { t.Fatal(err) } if res.ContentLength != 123 { t.Fatalf("Content-Length = %d; want 123", res.ContentLength) } var buf bytes.Buffer n, err := io.Copy(&buf, res.Body) if n != int64(len(shortBody)) { t.Errorf("Copied %d bytes; want %d, len(%q)", n, len(shortBody), shortBody) } if buf.String() != shortBody { t.Errorf("Read body %q; want %q", buf.String(), shortBody) } if err != io.ErrUnexpectedEOF { t.Errorf("io.Copy error = %#v; want io.ErrUnexpectedEOF", err) } } // Test various ReadResponse error cases. (also tests success cases, but mostly // it's about errors). This does not test anything involving the bodies. Only // the return value from ReadResponse itself. func TestReadResponseErrors(t *testing.T) { type testCase struct { name string // optional, defaults to in in string wantErr interface{} // nil, err value, or string substring } status := func(s string, wantErr interface{}) testCase { if wantErr == true { wantErr = "malformed HTTP status code" } return testCase{ name: fmt.Sprintf("status %q", s), in: "HTTP/1.1 " + s + "\r\nFoo: bar\r\n\r\n", wantErr: wantErr, } } version := func(s string, wantErr interface{}) testCase { if wantErr == true { wantErr = "malformed HTTP version" } return testCase{ name: fmt.Sprintf("version %q", s), in: s + " 200 OK\r\n\r\n", wantErr: wantErr, } } contentLength := func(status, body string, wantErr interface{}) testCase { return testCase{ name: fmt.Sprintf("status %q %q", status, body), in: fmt.Sprintf("HTTP/1.1 %s\r\n%s", status, body), wantErr: wantErr, } } errMultiCL := "message cannot contain multiple Content-Length headers" tests := []testCase{ {"", "", io.ErrUnexpectedEOF}, {"", "HTTP/1.1 301 Moved Permanently\r\nFoo: bar", io.ErrUnexpectedEOF}, {"", "HTTP/1.1", "malformed HTTP response"}, {"", "HTTP/2.0", "malformed HTTP response"}, status("20X Unknown", true), status("abcd Unknown", true), status("二百/两百 OK", true), status(" Unknown", true), status("c8 OK", true), status("0x12d Moved Permanently", true), status("200 OK", nil), status("000 OK", nil), status("001 OK", nil), status("404 NOTFOUND", nil), status("20 OK", true), status("00 OK", true), status("-10 OK", true), status("1000 OK", true), status("999 Done", nil), status("-1 OK", true), status("-200 OK", true), version("HTTP/1.2", nil), version("HTTP/2.0", nil), version("HTTP/1.100000000002", true), version("HTTP/1.-1", true), version("HTTP/A.B", true), version("HTTP/1", true), version("http/1.1", true), contentLength("200 OK", "Content-Length: 10\r\nContent-Length: 7\r\n\r\nGopher hey\r\n", errMultiCL), contentLength("200 OK", "Content-Length: 7\r\nContent-Length: 7\r\n\r\nGophers\r\n", nil), contentLength("201 OK", "Content-Length: 0\r\nContent-Length: 7\r\n\r\nGophers\r\n", errMultiCL), contentLength("300 OK", "Content-Length: 0\r\nContent-Length: 0 \r\n\r\nGophers\r\n", nil), contentLength("200 OK", "Content-Length:\r\nContent-Length:\r\n\r\nGophers\r\n", nil), contentLength("206 OK", "Content-Length:\r\nContent-Length: 0 \r\nConnection: close\r\n\r\nGophers\r\n", errMultiCL), // multiple content-length headers for 204 and 304 should still be checked contentLength("204 OK", "Content-Length: 7\r\nContent-Length: 8\r\n\r\n", errMultiCL), contentLength("204 OK", "Content-Length: 3\r\nContent-Length: 3\r\n\r\n", nil), contentLength("304 OK", "Content-Length: 880\r\nContent-Length: 1\r\n\r\n", errMultiCL), contentLength("304 OK", "Content-Length: 961\r\nContent-Length: 961\r\n\r\n", nil), // golang.org/issue/22464 {"leading space in header", "HTTP/1.1 200 OK\r\n Content-type: text/html\r\nFoo: bar\r\n\r\n", "malformed MIME"}, {"leading tab in header", "HTTP/1.1 200 OK\r\n\tContent-type: text/html\r\nFoo: bar\r\n\r\n", "malformed MIME"}, } for i, tt := range tests { br := bufio.NewReader(strings.NewReader(tt.in)) _, rerr := ReadResponse(br, nil) if err := matchErr(rerr, tt.wantErr); err != nil { name := tt.name if name == "" { name = fmt.Sprintf("%d. input %q", i, tt.in) } t.Errorf("%s: %v", name, err) } } } // wantErr can be nil, an error value to match exactly, or type string to // match a substring. func matchErr(err error, wantErr interface{}) error { if err == nil { if wantErr == nil { return nil } if sub, ok := wantErr.(string); ok { return fmt.Errorf("unexpected success; want error with substring %q", sub) } return fmt.Errorf("unexpected success; want error %v", wantErr) } if wantErr == nil { return fmt.Errorf("%v; want success", err) } if sub, ok := wantErr.(string); ok { if strings.Contains(err.Error(), sub) { return nil } return fmt.Errorf("error = %v; want an error with substring %q", err, sub) } if err == wantErr { return nil } return fmt.Errorf("%v; want %v", err, wantErr) } func TestNeedsSniff(t *testing.T) { // needsSniff returns true with an empty response. r := &response{} if got, want := r.needsSniff(), true; got != want { t.Errorf("needsSniff = %t; want %t", got, want) } // needsSniff returns false when Content-Type = nil. r.handlerHeader = Header{"Content-Type": nil} if got, want := r.needsSniff(), false; got != want { t.Errorf("needsSniff empty Content-Type = %t; want %t", got, want) } } // A response should only write out single Connection: close header. Tests #19499. func TestResponseWritesOnlySingleConnectionClose(t *testing.T) { const connectionCloseHeader = "Connection: close" res, err := ReadResponse(bufio.NewReader(strings.NewReader("HTTP/1.0 200 OK\r\n\r\nAAAA")), nil) if err != nil { t.Fatalf("ReadResponse failed %v", err) } var buf1 bytes.Buffer if err = res.Write(&buf1); err != nil { t.Fatalf("Write failed %v", err) } if res, err = ReadResponse(bufio.NewReader(&buf1), nil); err != nil { t.Fatalf("ReadResponse failed %v", err) } var buf2 bytes.Buffer if err = res.Write(&buf2); err != nil { t.Fatalf("Write failed %v", err) } if count := strings.Count(buf2.String(), connectionCloseHeader); count != 1 { t.Errorf("Found %d %q header", count, connectionCloseHeader) } }