Review event function closures

[andyhasit]

Currently when we use :onXYZ:

<button :onClick=".btnClicked">

The babel plugin creates a closure around view.btnClicked(e, w):

p.__bv = function (view, prototype) {
  view.dom = {
    '_1_': view.__gw([0]).on('click', function (e, w) {
      view.btnClicked(e, w);
    })
  };
};

Whereas we could cut out the closure:

p.__bv = function (view, prototype) {
  view.dom = {
    '_1_': view.__gw([0]).on('click', view.btnClicked)
  };
};

But we need to make sure we can still cater for arguments like a basic onClick:

<button :onClick=".btnClicked('hello')">

Perhaps conditionally determine whether this is happening and cut out the closure if not needed?

See:

redrunner/packages/babel-plugin-redrunner/lib/redrunner/syntax.js

Line 70 in a819313

const buildEventCallback = (statement) => {