feat(log): add zap.Slog accessor for slog-compatible consumers

go.mod

@@ -22,7 +22,8 @@ require (
 	go.opentelemetry.io/otel/trace v1.44.0
 	go.uber.org/mock v0.6.0
 	go.uber.org/zap v1.28.0
-	google.golang.org/grpc v1.81.1
+	go.uber.org/zap/exp v0.3.0
+	google.golang.org/grpc v1.82.1
 )
 
 require (

go.sum

@@ -112,6 +112,8 @@ go.uber.org/multierr v1.11.0 h1:blXXJkSxSSfBVBlC76pxqeO+LN3aDfLQo+309xJstO0=
 go.uber.org/multierr v1.11.0/go.mod h1:20+QtiLqy0Nd6FdQB9TLXag12DsQkrbs3htMFfDN80Y=
 go.uber.org/zap v1.28.0 h1:IZzaP1Fv73/T/pBMLk4VutPl36uNC+OSUh3JLG3FIjo=
 go.uber.org/zap v1.28.0/go.mod h1:rDLpOi171uODNm/mxFcuYWxDsqWSAVkFdX4XojSKg/Q=
+go.uber.org/zap/exp v0.3.0 h1:6JYzdifzYkGmTdRR59oYH+Ng7k49H9qVpWwNSsGJj3U=
+go.uber.org/zap/exp v0.3.0/go.mod h1:5I384qq7XGxYyByIhHm6jg5CHkGY0nsTfbDLgDDlgJQ=
 go.yaml.in/yaml/v3 v3.0.4 h1:tfq32ie2Jv2UxXFdLJdh3jXuOzWiL1fo0bu/FbuKpbc=
 go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
 golang.org/x/crypto v0.53.0 h1:QZ4Muo8THX6CizN2vPPd5fBGHyogrdK9fG4wLPFUsto=
@@ -130,8 +132,8 @@ google.golang.org/genproto/googleapis/api v0.0.0-20260526163538-3dc84a4a5aaa h1:
 google.golang.org/genproto/googleapis/api v0.0.0-20260526163538-3dc84a4a5aaa/go.mod h1:q4lMZS6kskjT5HvCPrnnypcDPVJqT/f4nfxmkE7gryY=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20260526163538-3dc84a4a5aaa h1:mZHHdPZl0dbGHCflZgAq/Q468DWVFcU2whhB2KAo8fk=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20260526163538-3dc84a4a5aaa/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
-google.golang.org/grpc v1.81.1 h1:VnnIIZ88UzOOKLukQi+ImGz8O1Wdp8nAGGnvOfEIWQQ=
-google.golang.org/grpc v1.81.1/go.mod h1:xGH9GfzOyMTGIOXBJmXt+BX/V0kcdQbdcuwQ/zNw42I=
+google.golang.org/grpc v1.82.1 h1:NnAxzGRA0677vCa4BUkOAnO5+FfQqVl9iUXeD0IqcGE=
+google.golang.org/grpc v1.82.1/go.mod h1:yzTZ1TB1Z3SG+LIYaI+WiE8D5+PZ3ArnrSp8zF3+/ZA=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

zap/slog.go

@@ -0,0 +1,27 @@
+package zap
+
+import (
+	"io"
+	"log/slog"
+
+	logpkg "github.com/LerianStudio/lib-observability/v2/log"
+	"go.uber.org/zap/exp/zapslog"
+)
+
+// Slog adapts a log.Logger to a stdlib *slog.Logger, so it can be handed to
+// libraries that accept an slog-compatible logger (for example
+// lib-service-discovery's libsd.WithLogger) without exposing any
+// lib-observability type on the boundary.
+//
+// When l is zap-backed — the production path, since czap.New returns *Logger —
+// the returned *slog.Logger writes through the very same zap core, so its output
+// stays unified with the rest of the service's logs. Any other implementation
+// (the nil logger, gomock doubles) falls back to a discarding handler rather
+// than panicking, mirroring the "unknown logger is silent" posture elsewhere.
+func Slog(l logpkg.Logger) *slog.Logger {
+	if zl, ok := l.(*Logger); ok {
+		return slog.New(zapslog.NewHandler(zl.Raw().Core()))
+	}
+
+	return slog.New(slog.NewTextHandler(io.Discard, nil))
+}

zap/slog_test.go

@@ -0,0 +1,48 @@
+//go:build unit
+
+package zap
+
+import (
+	"context"
+	"testing"
+
+	logpkg "github.com/LerianStudio/lib-observability/v2/log"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest/observer"
+)
+
+func TestSlog_WritesThroughZapCore(t *testing.T) {
+	core, observed := observer.New(zapcore.InfoLevel)
+	l := &Logger{logger: zap.New(core)}
+
+	Slog(l).InfoContext(context.Background(), "resolved", "consul", "localhost:8500")
+
+	require.Equal(t, 1, observed.Len())
+	entry := observed.All()[0]
+	assert.Equal(t, "resolved", entry.Message)
+	assert.Equal(t, zapcore.InfoLevel, entry.Level)
+	assert.Equal(t, "localhost:8500", entry.ContextMap()["consul"])
+}
+
+func TestSlog_NonZapLoggerFallsBackWithoutPanic(t *testing.T) {
+	got := Slog(logpkg.NewNop())
+
+	require.NotNil(t, got)
+	assert.NotPanics(t, func() {
+		got.InfoContext(context.Background(), "discarded")
+	})
+}
+
+func TestSlog_NilConcreteLoggerIsSafe(t *testing.T) {
+	var l *Logger
+
+	got := Slog(l)
+
+	require.NotNil(t, got)
+	assert.NotPanics(t, func() {
+		got.InfoContext(context.Background(), "no panic on nil receiver")
+	})
+}