lib: handle cause case

Author: mertcanaltin

lib/logger.js

@@ -7,6 +7,7 @@ const {
   ObjectAssign,
   ObjectKeys,
   ObjectPrototypeToString,
+  SafeSet,
 } = primordials;
 
 const {
@@ -331,22 +332,38 @@ class Logger {
   }
 
   /**
-   * Serialize Error object for logging
+   * Serialize Error object for logging (with recursive cause handling)
    * @param {object} err - Error object to serialize
+   * @param {Set} [seen] - Set to track circular references
    * @returns {object} Serialized error object
    * @private
    */
-  _serializeError(err) {
+  _serializeError(err, seen = new SafeSet()) {
+    if (seen.has(err)) {
+      return '[Circular]';
+    }
+    seen.add(err);
+
     const serialized = {
       message: err.message,
       name: err.name,
       stack: err.stack,
     };
 
-    serialized.code ||= err.code;
+    if (err.code !== undefined) {
+      serialized.code = err.code;
+    }
+
+    if (err.cause !== undefined) {
+      serialized.cause = this._isError(err.cause) ?
+        this._serializeError(err.cause, seen) :
+        err.cause;
+    }
 
     for (const key in err) {
-      serialized[key] ||= err[key];
+      if (serialized[key] === undefined) {
+        serialized[key] = err[key];
+      }
     }
 
     return serialized;