refactor

frontend/src/hooks/documents/useDocumentDragHandlers.ts

@@ -1,5 +1,6 @@
 import { useCallback, useEffect, useRef } from 'react';
 import type { DragEvent } from 'react';
+import { isPlainObject, isFunctionValue } from '../../utils/typeGuards';
 
 type Identifier = string | number;
 type FolderIdentifier = Identifier | 'root';
@@ -144,11 +145,17 @@ const useDocumentDragHandlers = ({
           }
         } else {
           const payload = item.payload;
-          const folderId = (payload && typeof payload === 'object' && 'id' in payload)
-            ? (payload as { id?: FolderIdentifier }).id
-            : (typeof (payload as { trim?: () => string })?.trim === 'function'
-              ? (payload as { trim: () => string }).trim()
-              : null);
+          const folderId = (() => {
+            if (isPlainObject(payload) && 'id' in payload) {
+              return (payload as { id?: FolderIdentifier }).id ?? null;
+            }
+            const maybeTrim = (payload as { trim?: () => string })?.trim;
+            if (isFunctionValue(maybeTrim)) {
+              const nextValue = maybeTrim.call(payload);
+              return nextValue || null;
+            }
+            return null;
+          })();
           const rowEl = folderId
             ? (document.getElementById(`folder-row-${folderId}`)
               || document.getElementById(`folder-card-${folderId}`))
@@ -205,10 +212,9 @@ const useDocumentDragHandlers = ({
 
   const handleDocumentDragStart = useCallback(
     (event: DragEvent<HTMLElement>, documentOrId: DocumentLike | Identifier | null | undefined) => {
-      const documentId =
-        (documentOrId as DocumentLike)?.id ?? (typeof documentOrId === 'string' || typeof documentOrId === 'number'
-          ? documentOrId
-          : null);
+      const documentId: Identifier | null = Object(documentOrId) === documentOrId
+        ? (documentOrId as DocumentLike)?.id ?? null
+        : (documentOrId as Identifier | null);
       if (!documentId) {
         return;
       }