// Copyright (c) Tailscale Inc & AUTHORS // SPDX-License-Identifier: BSD-3-Clause package logtail import ( "bytes" "context" "encoding/json" "io" "net/http" "net/http/httptest" "strings" "testing" "time" "github.com/go-json-experiment/json/jsontext" "tailscale.com/envknob" "tailscale.com/tstest" "tailscale.com/tstime" "tailscale.com/util/must" ) func TestFastShutdown(t *testing.T) { ctx, cancel := context.WithCancel(context.Background()) cancel() testServ := httptest.NewServer(http.HandlerFunc( func(w http.ResponseWriter, r *http.Request) {})) defer testServ.Close() l := NewLogger(Config{ BaseURL: testServ.URL, }, t.Logf) err := l.Shutdown(ctx) if err != nil { t.Error(err) } } // maximum number of times a test will call l.Write() const logLines = 3 type LogtailTestServer struct { srv *httptest.Server // Log server uploaded chan []byte } func NewLogtailTestHarness(t *testing.T) (*LogtailTestServer, *Logger) { ts := LogtailTestServer{} // max channel backlog = 1 "started" + #logLines x "log line" + 1 "closed" ts.uploaded = make(chan []byte, 2+logLines) ts.srv = httptest.NewServer(http.HandlerFunc( func(w http.ResponseWriter, r *http.Request) { body, err := io.ReadAll(r.Body) if err != nil { t.Error("failed to read HTTP request") } ts.uploaded <- body })) t.Cleanup(ts.srv.Close) l := NewLogger(Config{BaseURL: ts.srv.URL}, t.Logf) // There is always an initial "logtail started" message body := <-ts.uploaded if !strings.Contains(string(body), "started") { t.Errorf("unknown start logging statement: %q", string(body)) } return &ts, l } func TestDrainPendingMessages(t *testing.T) { ts, l := NewLogtailTestHarness(t) for range logLines { l.Write([]byte("log line")) } // all of the "log line" messages usually arrive at once, but poll if needed. body := "" for i := 0; i <= logLines; i++ { body += string(<-ts.uploaded) count := strings.Count(body, "log line") if count == logLines { break } // if we never find count == logLines, the test will eventually time out. } err := l.Shutdown(context.Background()) if err != nil { t.Error(err) } } func TestEncodeAndUploadMessages(t *testing.T) { ts, l := NewLogtailTestHarness(t) tests := []struct { name string log string want string }{ { "plain text", "log line", "log line", }, { "simple JSON", `{"text":"log line"}`, "log line", }, } for _, tt := range tests { io.WriteString(l, tt.log) body := <-ts.uploaded data := unmarshalOne(t, body) got := data["text"] if got != tt.want { t.Errorf("%s: got %q; want %q", tt.name, got.(string), tt.want) } ltail, ok := data["logtail"] if ok { logtailmap := ltail.(map[string]any) _, ok = logtailmap["client_time"] if !ok { t.Errorf("%s: no client_time present", tt.name) } } else { t.Errorf("%s: no logtail map present", tt.name) } } err := l.Shutdown(context.Background()) if err != nil { t.Error(err) } } func TestLoggerWriteLength(t *testing.T) { lg := &Logger{ clock: tstime.StdClock{}, buffer: NewMemoryBuffer(1024), } inBuf := []byte("some text to encode") n, err := lg.Write(inBuf) if err != nil { t.Error(err) } if n != len(inBuf) { t.Errorf("logger.Write wrote %d bytes, expected %d", n, len(inBuf)) } } func TestParseAndRemoveLogLevel(t *testing.T) { tests := []struct { log string wantLevel int wantLog string }{ { "no level", 0, "no level", }, { "[v1] level 1", 1, "level 1", }, { "level 1 [v1] ", 1, "level 1 ", }, { "[v2] level 2", 2, "level 2", }, { "level [v2] 2", 2, "level 2", }, { "[v3] no level 3", 0, "[v3] no level 3", }, { "some ignored text then [v\x00JSON]5{\"foo\":1234}", 5, `{"foo":1234}`, }, } for _, tt := range tests { gotLevel, gotLog := parseAndRemoveLogLevel([]byte(tt.log)) if gotLevel != tt.wantLevel { t.Errorf("parseAndRemoveLogLevel(%q): got:%d; want %d", tt.log, gotLevel, tt.wantLevel) } if string(gotLog) != tt.wantLog { t.Errorf("parseAndRemoveLogLevel(%q): got:%q; want %q", tt.log, gotLog, tt.wantLog) } } } func unmarshalOne(t *testing.T, body []byte) map[string]any { t.Helper() var entries []map[string]any err := json.Unmarshal(body, &entries) if err != nil { t.Error(err) } if len(entries) != 1 { t.Fatalf("expected one entry, got %d", len(entries)) } return entries[0] } type simpleMemBuf struct { Buffer buf bytes.Buffer } func (b *simpleMemBuf) Write(p []byte) (n int, err error) { return b.buf.Write(p) } func TestEncode(t *testing.T) { tests := []struct { in string want string }{ { "normal", `{"logtail":{"client_time":"1970-01-01T00:02:03.000000456Z","proc_id":7,"proc_seq":1},"text":"normal"}` + "\n", }, { "and a [v1] level one", `{"logtail":{"client_time":"1970-01-01T00:02:03.000000456Z","proc_id":7,"proc_seq":1},"v":1,"text":"and a level one"}` + "\n", }, { "[v2] some verbose two", `{"logtail":{"client_time":"1970-01-01T00:02:03.000000456Z","proc_id":7,"proc_seq":1},"v":2,"text":"some verbose two"}` + "\n", }, { "{}", `{"logtail":{"client_time":"1970-01-01T00:02:03.000000456Z","proc_id":7,"proc_seq":1}}` + "\n", }, { `{"foo":"bar"}`, `{"logtail":{"client_time":"1970-01-01T00:02:03.000000456Z","proc_id":7,"proc_seq":1},"foo":"bar"}` + "\n", }, { "foo: [v\x00JSON]0{\"foo\":1}", "{\"logtail\":{\"client_time\":\"1970-01-01T00:02:03.000000456Z\",\"proc_id\":7,\"proc_seq\":1},\"foo\":1}\n", }, { "foo: [v\x00JSON]2{\"foo\":1}", "{\"logtail\":{\"client_time\":\"1970-01-01T00:02:03.000000456Z\",\"proc_id\":7,\"proc_seq\":1},\"v\":2,\"foo\":1}\n", }, } for _, tt := range tests { buf := new(simpleMemBuf) lg := &Logger{ clock: tstest.NewClock(tstest.ClockOpts{Start: time.Unix(123, 456).UTC()}), buffer: buf, procID: 7, procSequence: 1, } io.WriteString(lg, tt.in) got := buf.buf.String() if got != tt.want { t.Errorf("for %q,\n got: %#q\nwant: %#q\n", tt.in, got, tt.want) } if err := json.Compact(new(bytes.Buffer), buf.buf.Bytes()); err != nil { t.Errorf("invalid output JSON for %q: %s", tt.in, got) } } } // Test that even if Logger.Write modifies the input buffer, we still return the // length of the input buffer, not what we shrank it down to. Otherwise the // caller will think we did a short write, violating the io.Writer contract. func TestLoggerWriteResult(t *testing.T) { buf := NewMemoryBuffer(100) lg := &Logger{ clock: tstest.NewClock(tstest.ClockOpts{Start: time.Unix(123, 0)}), buffer: buf, } const in = "[v1] foo" n, err := lg.Write([]byte(in)) if err != nil { t.Fatal(err) } if got, want := n, len(in); got != want { t.Errorf("Write = %v; want %v", got, want) } back, err := buf.TryReadLine() if err != nil { t.Fatal(err) } if got, want := string(back), `{"logtail":{"client_time":"1970-01-01T00:02:03Z"},"v":1,"text":"foo"}`+"\n"; got != want { t.Errorf("mismatch.\n got: %#q\nwant: %#q", back, want) } } func TestRedact(t *testing.T) { envknob.Setenv("TS_OBSCURE_LOGGED_IPS", "true") tests := []struct { in string want string }{ // tests for ipv4 addresses { "120.100.30.47", "120.100.x.x", }, { "192.167.0.1/65", "192.167.x.x/65", }, { "node [5Btdd] d:e89a3384f526d251 now using 10.0.0.222:41641 mtu=1360 tx=d81a8a35a0ce", "node [5Btdd] d:e89a3384f526d251 now using 10.0.x.x:41641 mtu=1360 tx=d81a8a35a0ce", }, //tests for ipv6 addresses { "2001:0db8:85a3:0000:0000:8a2e:0370:7334", "2001:0db8:x", }, { "2345:0425:2CA1:0000:0000:0567:5673:23b5", "2345:0425:x", }, { "2601:645:8200:edf0::c9de/64", "2601:645:x/64", }, { "node [5Btdd] d:e89a3384f526d251 now using 2051:0000:140F::875B:131C mtu=1360 tx=d81a8a35a0ce", "node [5Btdd] d:e89a3384f526d251 now using 2051:0000:x mtu=1360 tx=d81a8a35a0ce", }, { "2601:645:8200:edf0::c9de/64 2601:645:8200:edf0:1ce9:b17d:71f5:f6a3/64", "2601:645:x/64 2601:645:x/64", }, //tests for tailscale ip addresses { "100.64.5.6", "100.64.5.6", }, { "fd7a:115c:a1e0::/96", "fd7a:115c:a1e0::/96", }, //tests for ipv6 and ipv4 together { "192.167.0.1 2001:0db8:85a3:0000:0000:8a2e:0370:7334", "192.167.x.x 2001:0db8:x", }, { "node [5Btdd] d:e89a3384f526d251 now using 10.0.0.222:41641 mtu=1360 tx=d81a8a35a0ce 2345:0425:2CA1::0567:5673:23b5", "node [5Btdd] d:e89a3384f526d251 now using 10.0.x.x:41641 mtu=1360 tx=d81a8a35a0ce 2345:0425:x", }, { "100.64.5.6 2091:0db8:85a3:0000:0000:8a2e:0370:7334", "100.64.5.6 2091:0db8:x", }, { "192.167.0.1 120.100.30.47 2041:0000:140F::875B:131B", "192.167.x.x 120.100.x.x 2041:0000:x", }, { "fd7a:115c:a1e0::/96 192.167.0.1 2001:0db8:85a3:0000:0000:8a2e:0370:7334", "fd7a:115c:a1e0::/96 192.167.x.x 2001:0db8:x", }, } for _, tt := range tests { gotBuf := redactIPs([]byte(tt.in)) if string(gotBuf) != tt.want { t.Errorf("for %q,\n got: %#q\nwant: %#q\n", tt.in, gotBuf, tt.want) } } } func TestAppendMetadata(t *testing.T) { var l Logger l.clock = tstest.NewClock(tstest.ClockOpts{Start: time.Date(2000, 01, 01, 0, 0, 0, 0, time.UTC)}) l.metricsDelta = func() string { return "metrics" } for _, tt := range []struct { skipClientTime bool skipMetrics bool procID uint32 procSeq uint64 errDetail string errData jsontext.Value level int want string }{ {want: `"logtail":{"client_time":"2000-01-01T00:00:00Z"},"metrics":"metrics",`}, {skipClientTime: true, want: `"metrics":"metrics",`}, {skipMetrics: true, want: `"logtail":{"client_time":"2000-01-01T00:00:00Z"},`}, {skipClientTime: true, skipMetrics: true, want: ``}, {skipClientTime: true, skipMetrics: true, procID: 1, want: `"logtail":{"proc_id":1},`}, {skipClientTime: true, skipMetrics: true, procSeq: 2, want: `"logtail":{"proc_seq":2},`}, {skipClientTime: true, skipMetrics: true, procID: 1, procSeq: 2, want: `"logtail":{"proc_id":1,"proc_seq":2},`}, {skipMetrics: true, procID: 1, procSeq: 2, want: `"logtail":{"client_time":"2000-01-01T00:00:00Z","proc_id":1,"proc_seq":2},`}, {skipClientTime: true, skipMetrics: true, errDetail: "error", want: `"logtail":{"error":{"detail":"error"}},`}, {skipClientTime: true, skipMetrics: true, errData: jsontext.Value("null"), want: `"logtail":{"error":{"bad_data":null}},`}, {skipClientTime: true, skipMetrics: true, level: 5, want: `"v":5,`}, {procID: 1, procSeq: 2, errDetail: "error", errData: jsontext.Value(`["something","bad","happened"]`), level: 2, want: `"logtail":{"client_time":"2000-01-01T00:00:00Z","proc_id":1,"proc_seq":2,"error":{"detail":"error","bad_data":["something","bad","happened"]}},"metrics":"metrics","v":2,`}, } { got := string(l.appendMetadata(nil, tt.skipClientTime, tt.skipMetrics, tt.procID, tt.procSeq, tt.errDetail, tt.errData, tt.level)) if got != tt.want { t.Errorf("appendMetadata(%v, %v, %v, %v, %v, %v, %v):\n\tgot %s\n\twant %s", tt.skipClientTime, tt.skipMetrics, tt.procID, tt.procSeq, tt.errDetail, tt.errData, tt.level, got, tt.want) } gotObj := "{" + strings.TrimSuffix(got, ",") + "}" if !jsontext.Value(gotObj).IsValid() { t.Errorf("`%s`.IsValid() = false, want true", gotObj) } } } func TestAppendText(t *testing.T) { var l Logger l.clock = tstest.NewClock(tstest.ClockOpts{Start: time.Date(2000, 01, 01, 0, 0, 0, 0, time.UTC)}) l.metricsDelta = func() string { return "metrics" } l.lowMem = true for _, tt := range []struct { text string skipClientTime bool procID uint32 procSeq uint64 level int want string }{ {want: `{"logtail":{"client_time":"2000-01-01T00:00:00Z"},"metrics":"metrics"}`}, {skipClientTime: true, want: `{"metrics":"metrics"}`}, {skipClientTime: true, procID: 1, procSeq: 2, want: `{"logtail":{"proc_id":1,"proc_seq":2},"metrics":"metrics"}`}, {text: "fizz buzz", want: `{"logtail":{"client_time":"2000-01-01T00:00:00Z"},"metrics":"metrics","text":"fizz buzz"}`}, {text: "\b\f\n\r\t\"\\", want: `{"logtail":{"client_time":"2000-01-01T00:00:00Z"},"metrics":"metrics","text":"\b\f\n\r\t\"\\"}`}, {text: "x" + strings.Repeat("😐", maxSize), want: `{"logtail":{"client_time":"2000-01-01T00:00:00Z"},"metrics":"metrics","text":"x` + strings.Repeat("😐", 1023) + `…+1044484"}`}, } { got := string(l.appendText(nil, []byte(tt.text), tt.skipClientTime, tt.procID, tt.procSeq, tt.level)) if !strings.HasSuffix(got, "\n") { t.Errorf("`%s` does not end with a newline", got) } got = got[:len(got)-1] if got != tt.want { t.Errorf("appendText(%v, %v, %v, %v, %v):\n\tgot %s\n\twant %s", tt.text[:min(len(tt.text), 256)], tt.skipClientTime, tt.procID, tt.procSeq, tt.level, got, tt.want) } if !jsontext.Value(got).IsValid() { t.Errorf("`%s`.IsValid() = false, want true", got) } } } func TestAppendTextOrJSON(t *testing.T) { var l Logger l.clock = tstest.NewClock(tstest.ClockOpts{Start: time.Date(2000, 01, 01, 0, 0, 0, 0, time.UTC)}) l.metricsDelta = func() string { return "metrics" } l.lowMem = true for _, tt := range []struct { in string level int want string }{ {want: `{"logtail":{"client_time":"2000-01-01T00:00:00Z"},"metrics":"metrics"}`}, {in: "[]", want: `{"logtail":{"client_time":"2000-01-01T00:00:00Z"},"metrics":"metrics","text":"[]"}`}, {level: 1, want: `{"logtail":{"client_time":"2000-01-01T00:00:00Z"},"metrics":"metrics","v":1}`}, {in: `{}`, want: `{"logtail":{"client_time":"2000-01-01T00:00:00Z"}}`}, {in: `{}{}`, want: `{"logtail":{"client_time":"2000-01-01T00:00:00Z"},"metrics":"metrics","text":"{}{}"}`}, {in: "{\n\"fizz\"\n:\n\"buzz\"\n}", want: `{"logtail":{"client_time":"2000-01-01T00:00:00Z"},"fizz":"buzz"}`}, {in: `{ "logtail" : "duplicate" }`, want: `{"logtail":{"client_time":"2000-01-01T00:00:00Z","error":{"detail":"duplicate logtail member","bad_data":"duplicate"}}}`}, {in: `{ "fizz" : "buzz" , "logtail" : "duplicate" }`, want: `{"logtail":{"client_time":"2000-01-01T00:00:00Z","error":{"detail":"duplicate logtail member","bad_data":"duplicate"}}, "fizz" : "buzz"}`}, {in: `{ "logtail" : "duplicate" , "fizz" : "buzz" }`, want: `{"logtail":{"client_time":"2000-01-01T00:00:00Z","error":{"detail":"duplicate logtail member","bad_data":"duplicate"}} , "fizz" : "buzz"}`}, {in: `{ "fizz" : "buzz" , "logtail" : "duplicate" , "wizz" : "wuzz" }`, want: `{"logtail":{"client_time":"2000-01-01T00:00:00Z","error":{"detail":"duplicate logtail member","bad_data":"duplicate"}}, "fizz" : "buzz" , "wizz" : "wuzz"}`}, {in: `{"long":"` + strings.Repeat("a", maxSize) + `"}`, want: `{"logtail":{"client_time":"2000-01-01T00:00:00Z","error":{"detail":"entry too large: 262155 bytes","bad_data":"{\"long\":\"` + strings.Repeat("a", 43681) + `…+218465"}}}`}, } { got := string(l.appendTextOrJSONLocked(nil, []byte(tt.in), tt.level)) if !strings.HasSuffix(got, "\n") { t.Errorf("`%s` does not end with a newline", got) } got = got[:len(got)-1] if got != tt.want { t.Errorf("appendTextOrJSON(%v, %v):\n\tgot %s\n\twant %s", tt.in[:min(len(tt.in), 256)], tt.level, got, tt.want) } if !jsontext.Value(got).IsValid() { t.Errorf("`%s`.IsValid() = false, want true", got) } } } var sink []byte func TestAppendTextAllocs(t *testing.T) { lg := &Logger{clock: tstime.StdClock{}} inBuf := []byte("some text to encode") procID := uint32(0x24d32ee9) procSequence := uint64(0x12346) must.Do(tstest.MinAllocsPerRun(t, 0, func() { sink = lg.appendText(sink[:0], inBuf, false, procID, procSequence, 0) })) } func TestAppendJSONAllocs(t *testing.T) { lg := &Logger{clock: tstime.StdClock{}} inBuf := []byte(`{"fizz":"buzz"}`) must.Do(tstest.MinAllocsPerRun(t, 1, func() { sink = lg.appendTextOrJSONLocked(sink[:0], inBuf, 0) })) } type discardBuffer struct{ Buffer } func (discardBuffer) Write(p []byte) (n int, err error) { return n, nil } var testdataTextLog = []byte(`netcheck: report: udp=true v6=false v6os=true mapvarydest=false hair=false portmap= v4a=174.xxx.xxx.xxx:18168 derp=2 derpdist=1v4:82ms,2v4:18ms,3v4:214ms,4v4:171ms,5v4:196ms,7v4:124ms,8v4:149ms,9v4:56ms,10v4:32ms,11v4:196ms,12v4:71ms,13v4:48ms,14v4:166ms,16v4:85ms,17v4:25ms,18v4:153ms,19v4:176ms,20v4:193ms,21v4:84ms,22v4:182ms,24v4:73ms`) var testdataJSONLog = []byte(`{"end":"2024-04-08T21:39:15.715291586Z","nodeId":"nQRJBE7CNTRL","physicalTraffic":[{"dst":"127.x.x.x:2","src":"100.x.x.x:0","txBytes":148,"txPkts":1},{"dst":"127.x.x.x:2","src":"100.x.x.x:0","txBytes":148,"txPkts":1},{"dst":"98.x.x.x:1025","rxBytes":640,"rxPkts":5,"src":"100.x.x.x:0","txBytes":640,"txPkts":5},{"dst":"24.x.x.x:49973","rxBytes":640,"rxPkts":5,"src":"100.x.x.x:0","txBytes":640,"txPkts":5},{"dst":"73.x.x.x:41641","rxBytes":732,"rxPkts":6,"src":"100.x.x.x:0","txBytes":820,"txPkts":7},{"dst":"75.x.x.x:1025","rxBytes":640,"rxPkts":5,"src":"100.x.x.x:0","txBytes":640,"txPkts":5},{"dst":"75.x.x.x:41641","rxBytes":640,"rxPkts":5,"src":"100.x.x.x:0","txBytes":640,"txPkts":5},{"dst":"174.x.x.x:35497","rxBytes":13008,"rxPkts":98,"src":"100.x.x.x:0","txBytes":26688,"txPkts":150},{"dst":"47.x.x.x:41641","rxBytes":640,"rxPkts":5,"src":"100.x.x.x:0","txBytes":640,"txPkts":5},{"dst":"64.x.x.x:41641","rxBytes":640,"rxPkts":5,"src":"100.x.x.x:0","txBytes":640,"txPkts":5}],"start":"2024-04-08T21:39:11.099495616Z","virtualTraffic":[{"dst":"100.x.x.x:33008","proto":6,"src":"100.x.x.x:22","txBytes":1260,"txPkts":10},{"dst":"100.x.x.x:0","proto":1,"rxBytes":420,"rxPkts":5,"src":"100.x.x.x:0","txBytes":420,"txPkts":5},{"dst":"100.x.x.x:32984","proto":6,"src":"100.x.x.x:22","txBytes":1340,"txPkts":10},{"dst":"100.x.x.x:32998","proto":6,"src":"100.x.x.x:22","txBytes":1020,"txPkts":10},{"dst":"100.x.x.x:32994","proto":6,"src":"100.x.x.x:22","txBytes":1260,"txPkts":10},{"dst":"100.x.x.x:32980","proto":6,"src":"100.x.x.x:22","txBytes":1260,"txPkts":10},{"dst":"100.x.x.x:0","proto":1,"rxBytes":420,"rxPkts":5,"src":"100.x.x.x:0","txBytes":420,"txPkts":5},{"dst":"100.x.x.x:0","proto":1,"rxBytes":420,"rxPkts":5,"src":"100.x.x.x:0","txBytes":420,"txPkts":5},{"dst":"100.x.x.x:32950","proto":6,"src":"100.x.x.x:22","txBytes":1340,"txPkts":10},{"dst":"100.x.x.x:22","proto":6,"src":"100.x.x.x:53332","txBytes":60,"txPkts":1},{"dst":"100.x.x.x:0","proto":1,"src":"100.x.x.x:0","txBytes":420,"txPkts":5},{"dst":"100.x.x.x:0","proto":1,"rxBytes":420,"rxPkts":5,"src":"100.x.x.x:0","txBytes":420,"txPkts":5},{"dst":"100.x.x.x:32966","proto":6,"src":"100.x.x.x:22","txBytes":1260,"txPkts":10},{"dst":"100.x.x.x:22","proto":6,"src":"100.x.x.x:57882","txBytes":60,"txPkts":1},{"dst":"100.x.x.x:22","proto":6,"src":"100.x.x.x:53326","txBytes":60,"txPkts":1},{"dst":"100.x.x.x:22","proto":6,"src":"100.x.x.x:57892","txBytes":60,"txPkts":1},{"dst":"100.x.x.x:32934","proto":6,"src":"100.x.x.x:22","txBytes":8712,"txPkts":55},{"dst":"100.x.x.x:0","proto":1,"rxBytes":420,"rxPkts":5,"src":"100.x.x.x:0","txBytes":420,"txPkts":5},{"dst":"100.x.x.x:32942","proto":6,"src":"100.x.x.x:22","txBytes":1260,"txPkts":10},{"dst":"100.x.x.x:0","proto":1,"rxBytes":420,"rxPkts":5,"src":"100.x.x.x:0","txBytes":420,"txPkts":5},{"dst":"100.x.x.x:32964","proto":6,"src":"100.x.x.x:22","txBytes":1260,"txPkts":10},{"dst":"100.x.x.x:0","proto":1,"rxBytes":420,"rxPkts":5,"src":"100.x.x.x:0","txBytes":420,"txPkts":5},{"dst":"100.x.x.x:0","proto":1,"rxBytes":420,"rxPkts":5,"src":"100.x.x.x:0","txBytes":420,"txPkts":5},{"dst":"100.x.x.x:22","proto":6,"src":"100.x.x.x:37238","txBytes":60,"txPkts":1},{"dst":"100.x.x.x:22","proto":6,"src":"100.x.x.x:37252","txBytes":60,"txPkts":1}]}`) func BenchmarkWriteText(b *testing.B) { var l Logger l.clock = tstime.StdClock{} l.buffer = discardBuffer{} b.ReportAllocs() for range b.N { must.Get(l.Write(testdataTextLog)) } } func BenchmarkWriteJSON(b *testing.B) { var l Logger l.clock = tstime.StdClock{} l.buffer = discardBuffer{} b.ReportAllocs() for range b.N { must.Get(l.Write(testdataJSONLog)) } }