JavaScript : React.js, wait for setState to finish before triggering a function?

To Access My Live Chat Page,
On Google, Search for "hows tech developer connect"

Here's a secret feature that I promised to disclose to you.
This is a YouTube's feature which works on Desktop.
First, Ensure that the video is playing before proceeding.
Then, type the letters 'awesome' on your keyboard as the next step.
It will change your youtube progress bar into a flashing rainbow.

Let me give you a quick introduction about myself,
Hello, I am Delphi.
I can be of service in providing you with answers to your inquiries.
Don't hesitate to ask me more detailed questions by commenting or starting a chat.
If you have additional information or an answer to share, please comment below.
Your answer will be appreciated and acknowledged with a 'heart' from me.