fix(lib-storage): remove converting zero to undefined for zero byte length

Author: smilkuri

lib/lib-storage/src/Upload.spec.ts

@@ -859,7 +859,7 @@ describe(Upload.name, () => {
 
       expect(() => {
         (upload as any).__validateUploadPart(emptyPart, MOCK_PART_SIZE);
-      }).toThrow("A dataPart was generated without a measurable data chunk size for part number 1");
+      }).toThrow(`The byte size for part number 1, size 0 does not match expected size ${MOCK_PART_SIZE}`);
     });
 
     it("should skip validation for single-part uploads", () => {

lib/lib-storage/src/Upload.ts

@@ -438,7 +438,7 @@ export class Upload extends EventEmitter {
   }
 
   private __validateUploadPart(dataPart: RawDataPart): void {
-    const actualPartSize = byteLength(dataPart.data) || undefined;
+    const actualPartSize = byteLength(dataPart.data);
 
     if (actualPartSize === undefined) {
       throw new Error(