feat: add nextAppendPosition

Author: gxkl

lib/client.js

@@ -341,6 +341,10 @@ proto.requestError = async function requestError(result) {
     err.code = info.Code;
     err.requestId = info.RequestId;
     err.hostId = info.HostId;
+    // https://help.aliyun.com/zh/oss/support/http-status-code-409#section-rmc-hvd-j38
+    if (info.Code === 'PositionNotEqualToLength' && result.headers && result.headers['x-oss-next-append-position']) {
+      err.nextAppendPosition = result.headers['x-oss-next-append-position'];
+    }
   }
 
   debug('generate error %j', err);

test/object.test.js

@@ -2075,13 +2075,13 @@ describe('test/object.test.js', () => {
     it('should error when positio not match', async () => {
       await store.append(name, Buffer.from('foo'));
 
-      try {
-        await store.append(name, Buffer.from('foo'));
-        throw new Error('should not run');
-      } catch (err) {
-        assert(err.message === 'Position is not equal to file length');
-        assert(err.name === 'PositionNotEqualToLengthError');
-      }
+      await assert.rejects(
+        store.append(name, Buffer.from('foo')),
+        err =>
+          err.message === 'Position is not equal to file length' &&
+          err.name === 'PositionNotEqualToLengthError' &&
+          err.nextAppendPosition === '3'
+      );
     });
 
     it('should use nextAppendPosition to append next', async () => {