errors.go

@@ -104,7 +104,7 @@ func Wrap(err error, op, msg string) error {
 	if err == nil {
 		return nil
 	}
-	wrapped := &Err{Op: op, Msg: msg, Err: err, Code: ErrCode(err)}
+	wrapped := &Err{Op: op, Msg: msg, Err: err, Code: inheritedCode(err)}
 	inheritRecovery(wrapped, err)
 	return wrapped
 }
@@ -201,6 +201,17 @@ func inheritRecovery(dst *Err, err error) {
 	}
 }
 
+// inheritedCode returns the first non-empty code found in an error chain.
+func inheritedCode(err error) string {
+	for err != nil {
+		if wrapped, ok := err.(*Err); ok && wrapped.Code != "" {
+			return wrapped.Code
+		}
+		err = errors.Unwrap(err)
+	}
+	return ""
+}
+
 // RetryAfter returns the first retry-after hint from an error chain, if present.
 //
 //	retryAfter, ok := log.RetryAfter(err)

errors_test.go

@@ -124,6 +124,17 @@ func TestWrap_PreservesCode_Good(t *testing.T) {
 	assert.Contains(t, outer.Error(), "[VALIDATION_ERROR]")
 }
 
+func TestWrap_PreservesCode_FromNestedErrWithEmptyOuterCode_Good(t *testing.T) {
+	inner := WrapCode(errors.New("base"), "VALIDATION_ERROR", "inner.Op", "validation failed")
+	mid := &Err{Op: "mid.Op", Msg: "mid failed", Err: inner}
+
+	outer := Wrap(mid, "outer.Op", "outer context")
+
+	assert.NotNil(t, outer)
+	assert.Equal(t, "VALIDATION_ERROR", ErrCode(outer))
+	assert.Contains(t, outer.Error(), "[VALIDATION_ERROR]")
+}
+
 func TestWrap_PreservesRecovery_Good(t *testing.T) {
 	retryAfter := 15 * time.Second
 	inner := &Err{Msg: "inner", Retryable: true, RetryAfter: &retryAfter, NextAction: "inspect input"}