refactor upload file handling

apps/box-mgnt-api/src/mgnt-backend/feature/uploader/uploader.service.ts

@@ -204,19 +204,36 @@ export class UploaderService {
     maxBytes: number,
     rootPath: string,
   ): Promise<string> {
+    const toBuffer = (value: unknown): Buffer | undefined => {
+      if (!value) return undefined;
+      if (Buffer.isBuffer(value)) return value;
+      if (value instanceof Uint8Array) return Buffer.from(value);
+      if (Array.isArray(value)) return Buffer.from(value);
+      if (typeof value === 'object') {
+        try {
+          return Buffer.from(value as ArrayLike<number>);
+        } catch {
+          return undefined;
+        }
+      }
+      return undefined;
+    };
+
     let source = (file as any)?.file as NodeJS.ReadableStream | undefined;
     if (!source) {
-      if (Buffer.isBuffer(file) || file instanceof Uint8Array) {
-        source = Readable.from(file);
+      const buffer = toBuffer(file);
+      if (buffer) {
+        source = Readable.from(buffer);
       }
     }
     if (!source) {
-      const maybeBuffer =
+      const maybeBuffer = toBuffer(
         (file as any).buffer ??
         (file as any).value ??
         (file as any).data ??
-        undefined;
-      if (Buffer.isBuffer(maybeBuffer)) {
+        undefined,
+      );
+      if (maybeBuffer) {
         source = Readable.from(maybeBuffer);
       } else if (typeof (file as any).toBuffer === 'function') {
         const buffer = await (file as any).toBuffer();