refactor: small simplification

[Keuklar]

Description
small refactoring

Purpose
code factorisation / simplification / concision

[alvestrand]

The purpose of samples is to have code that is easy to understand.
While the suggestion uses many more Javascript constructs, I have trouble seeing how it is easier to understand than the old code.

[Keuklar]

ok I see, sorry for that, the main goal was to factor this code :

if (readyState === 'open') {
    dataChannelSend.disabled = false;
    dataChannelSend.focus();
    sendButton.disabled = false;
    closeButton.disabled = false;
  } else {
    dataChannelSend.disabled = true;
    sendButton.disabled = true;
    closeButton.disabled = true;
  }

which is a bit verbose, repetitive.
But I got a little carried away, I could just focus on the 'if...else' if you wish.
Something like that:

  const closed = readyState !== 'open'
  dataChannelSend.disabled = closed;
  sendButton.disabled = closed;
  closeButton.disabled = closed;
  if (!closed) {
    dataChannelSend.focus();
  }

[alvestrand]

That seems more readable, yes. (I would call the variable "isOpen" just because that's what the ready state is named. But that's taste.

[Keuklar]

So, I've made a new proposal, I let closed const, as you said it's a matter of taste, since I find it more straightforward.