Fix #7: implement AddSource flag, add as message

handler_test.go

@@ -115,6 +115,14 @@ var tests = []Tests{
 			Level: slog.LevelError,
 		},
 	},
+	{
+		name:   "has-source",
+		want:   "handler_test.go",
+		negate: false,
+		opts: yadu.Options{
+			AddSource: true,
+		},
+	},
 	{
 		// check if output is NOT colored when disabling it
 		name:   "disable-color",