addFiles event call sequence

[AndreyZSneg]

I'm submitting a: Bug report Current behavior: Currently our application on addFiles event triggers external api call and after call is executed we call resumable.upload. When file(s) is/are added, but not yet uploaded, and we add new file(s), resumable.upload is called before external api call is made.

Expected behavior addFiles event is triggered, at first external api call is executed and after that resumable.upload is called.

Minimal reproduction of the problem with instructions

• Launch application
• Add files to file upload component
• After addFiles event triggered and resumable.upload was initiated, add new files to upload component

Environment

• Package Version: 1.1.0
• OS: Windows 10
• Node version (node -v): 13.5.0
• Other: React 16.9.0

addFiles event code: resumable.on('filesAdded', (files: File[]) => { getAPICallWhichReternSomething(files).then(() => resumable.upload()); });