docs: add godoc and bilingual README

logger_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"errors"
 	"os"
+	"strings"
 	"testing"
 )
 
@@ -153,6 +154,42 @@ func TestCreateJsonStdoutWriterDoesNotCloseStdout(t *testing.T) {
 	}
 }
 
+func TestGetFullTracebackSkipsRuntimeAndSlogFrames(t *testing.T) {
+	tracebacks := captureTracebackForTest()
+	if len(tracebacks) == 0 {
+		t.Fatal("expected at least one traceback frame")
+	}
+
+	first := tracebacks[0]
+	if first.Method != "captureTracebackForTest" {
+		t.Fatalf("first frame should be the nearest user frame, got %s", first.Method)
+	}
+	for _, tb := range tracebacks {
+		if strings.HasPrefix(tb.Signature, "runtime.") {
+			t.Fatalf("runtime frame should be filtered out, got %s", tb.Signature)
+		}
+		if _, ok := internalTracebackMethods[tb.Method]; ok {
+			t.Fatalf("internal slog frame should be filtered out, got %s", tb.Signature)
+		}
+	}
+}
+
+func TestGetTracebackReturnsNearestUserFrame(t *testing.T) {
+	tb := captureSingleTracebackForTest()
+	if tb == nil {
+		t.Fatal("expected traceback frame")
+	}
+	if tb.Method != "captureSingleTracebackForTest" {
+		t.Fatalf("expected nearest user frame, got %s", tb.Method)
+	}
+	if strings.HasPrefix(tb.Signature, "runtime.") {
+		t.Fatalf("runtime frame should be filtered out, got %s", tb.Signature)
+	}
+	if _, ok := internalTracebackMethods[tb.Method]; ok {
+		t.Fatalf("internal slog frame should be filtered out, got %s", tb.Signature)
+	}
+}
+
 func swapStdout(t *testing.T) *os.File {
 	t.Helper()
 
@@ -168,3 +205,11 @@ func swapStdout(t *testing.T) *os.File {
 	})
 	return stdoutFile
 }
+
+func captureTracebackForTest() []*MethodTraceback {
+	return getFullTraceback(0)
+}
+
+func captureSingleTracebackForTest() *MethodTraceback {
+	return getTraceback()
+}