From 4c7e1607d4ce0a1c3b15d9b76f1befec718dac1d Mon Sep 17 00:00:00 2001
From: Vasiliy Tolstov <v.tolstov@unistack.org>
Date: Mon, 4 Mar 2024 22:54:11 +0300
Subject: [PATCH] logger/slog: add stacktrace support

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
---
 logger/slog/slog.go      | 21 +++++++++++++++++++++
 logger/slog/slog_test.go | 14 ++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/logger/slog/slog.go b/logger/slog/slog.go
index b2b756c3..bb569075 100644
--- a/logger/slog/slog.go
+++ b/logger/slog/slog.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log/slog"
 	"os"
+	"regexp"
 	"runtime"
 	"strconv"
 	"sync"
@@ -14,6 +15,8 @@ import (
 	"go.unistack.org/micro/v3/tracer"
 )
 
+var reTrace = regexp.MustCompile(`.*/slog/logger\.go.*\n`)
+
 var (
 	DefaultSourceKey  string = slog.SourceKey
 	DefaultTimeKey    string = slog.TimeKey
@@ -290,6 +293,15 @@ func (s *slogLogger) Error(ctx context.Context, attrs ...interface{}) {
 	runtime.Callers(s.opts.CallerSkipCount, pcs[:]) // skip [Callers, Infof]
 	r := slog.NewRecord(time.Now(), slog.LevelError, fmt.Sprintf("%s", attrs[0]), pcs[0])
 	//	r.Add(attrs[1:]...)
+	if s.opts.Stacktrace {
+		stackInfo := make([]byte, 1024*1024)
+		if stackSize := runtime.Stack(stackInfo, false); stackSize > 0 {
+			traceLines := reTrace.Split(string(stackInfo[:stackSize]), -1)
+			if len(traceLines) != 0 {
+				r.AddAttrs(slog.String("stacktrace", traceLines[len(traceLines)-1]))
+			}
+		}
+	}
 	r.Attrs(func(a slog.Attr) bool {
 		if a.Key == "error" {
 			if span, ok := tracer.SpanFromContext(ctx); ok {
@@ -310,6 +322,15 @@ func (s *slogLogger) Errorf(ctx context.Context, msg string, attrs ...interface{
 	runtime.Callers(s.opts.CallerSkipCount, pcs[:]) // skip [Callers, Infof]
 	r := slog.NewRecord(time.Now(), slog.LevelError, fmt.Sprintf(msg, attrs...), pcs[0])
 	// r.Add(attrs...)
+	if s.opts.Stacktrace {
+		stackInfo := make([]byte, 1024*1024)
+		if stackSize := runtime.Stack(stackInfo, false); stackSize > 0 {
+			traceLines := reTrace.Split(string(stackInfo[:stackSize]), -1)
+			if len(traceLines) != 0 {
+				r.AddAttrs(slog.String("stacktrace", traceLines[len(traceLines)-1]))
+			}
+		}
+	}
 	r.Attrs(func(a slog.Attr) bool {
 		if a.Key == "error" {
 			if span, ok := tracer.SpanFromContext(ctx); ok {
diff --git a/logger/slog/slog_test.go b/logger/slog/slog_test.go
index a6846c6f..62698e16 100644
--- a/logger/slog/slog_test.go
+++ b/logger/slog/slog_test.go
@@ -9,6 +9,20 @@ import (
 	"go.unistack.org/micro/v3/logger"
 )
 
+func TestError(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(logger.WithLevel(logger.ErrorLevel), logger.WithOutput(buf), logger.WithStacktrace(true))
+	if err := l.Init(); err != nil {
+		t.Fatal(err)
+	}
+
+	l.Error(ctx, "message")
+	if !bytes.Contains(buf.Bytes(), []byte(`"stacktrace":"`)) {
+		t.Fatalf("logger stacktrace not works, buf contains: %s", buf.Bytes())
+	}
+}
+
 func TestContext(t *testing.T) {
 	ctx := context.TODO()
 	buf := bytes.NewBuffer(nil)