Fix error handling and use segment_index starting from zero (#589)

* Update uploadMedia to use new dedicated endpoints for chunked media upload in V2

* Minor fixes

* Fix error handling in V2

* Use segment_index starting from zero

* Make sure segment_index starts from zero

Author: avillegasn

src/client-mixins/request-handler.helper.ts

@@ -98,7 +98,7 @@ export class RequestHandlerHelper<T> {
     if (data?.errors?.length) {
       const errors = data.errors as (ErrorV1 | ErrorV2)[];
 
-      if ('code' in errors[0]) {
+      if (typeof errors[0] === 'object' && 'code' in errors[0]) {
         errorString += ' - ' + this.formatV1Errors(errors as ErrorV1[]);
       }
       else {

src/v2/client.v2.write.ts

@@ -168,7 +168,7 @@ export default class TwitterApiv2ReadWrite extends TwitterApiv2ReadOnly {
       const chunkedBuffer = Buffer.from(mediaChunk);
 
       const appendArguments: MediaV2UploadAppendParams = {
-        segment_index: i + 1,
+        segment_index: i,
         media: chunkedBuffer,
       };