add an example test

xrayslog/example_test.go

@@ -0,0 +1,37 @@
+package xrayslog_test
+
+import (
+	"context"
+	"log/slog"
+	"os"
+
+	"github.com/shogo82148/aws-xray-yasdk-go/xray"
+	"github.com/shogo82148/aws-xray-yasdk-go/xrayslog"
+)
+
+func ExampleNewHandler() {
+	// it's for testing.
+	replace := func(groups []string, a slog.Attr) slog.Attr {
+		// Remove time.
+		if a.Key == slog.TimeKey && len(groups) == 0 {
+			return slog.Attr{}
+		}
+		return a
+	}
+
+	// build the logger
+	parent := slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{ReplaceAttr: replace})
+	h := xrayslog.NewHandler(parent, "trace_id")
+	logger := slog.New(h)
+
+	// begin a new segment
+	ctx := context.Background()
+	ctx, segment := xray.BeginSegmentWithHeader(ctx, "my-segment", "Root=1-5e645f3e-1dfad076a177c5ccc5de12f5")
+	defer segment.Close()
+
+	// output the log
+	logger.InfoContext(ctx, "hello")
+
+	// Output:
+	// level=INFO msg=hello trace_id=1-5e645f3e-1dfad076a177c5ccc5de12f5
+}

xrayslog/xrayslog.go

@@ -1,6 +1,7 @@
 //go:build go1.21
 // +build go1.21
 
+// Package xrayslog provides a [log/slog.Handler] that adds trace ID to the log record.
 package xrayslog
 
 import (