update

src/index.ts

@@ -84,18 +84,20 @@ export class OssBase implements OssBaseOperation {
     let size: number = opts?.size;
     const isStream = opts?.isStream;
     if (!isStream) {
-      if (data instanceof Object) {
-        putData = JSON.stringify(data);
-        size = putData.length;
-      } else if (typeof data === 'string') {
+      if (typeof data === 'string') {
         putData = data;
         size = putData.length;
       } else {
-        putData = data;
+        putData = JSON.stringify(data);
+        size = putData.length;
       }
     } else {
       putData = data as any;
-      size = null;
+      // 对于流式上传，如果没有提供 size，会导致多部分上传，ETag 会是 ****-1 格式
+      // 必须提供准确的 size 才能得到标准的 MD5 格式 ETag
+      if (!size) {
+        throw new Error('Stream upload requires size parameter to avoid multipart upload and get standard MD5 ETag');
+      }
     }
     if (opts?.check) {
       const obj = await this.statObject(objectName, true);