[BUG] render returns undefined to undefined empty nodes are also rebuilt

⌨️

Rax Core

Minimal code and steps to reproduce the bug

import { Component } from 'rax';

class UndefinedDemo extends Component {
  constructor(props) {
    super(props);

    this.state = {
      alwaysUndefined: false,
    };
  }

  render() {
    return (
      <div>
        {this.state.alwaysUndefined ? undefined : undefined}

        <button
          onClick={() => {
            this.setState({
              alwaysUndefined: !this.state.alwaysUndefined
            });
          }}
        >
          Switch
        </button>
      </div>
    )
  }
}

reference: fix: render returns null to null empty nodes are also rebuilt(#1830) #1842

shouldUpdateComponent method should also checkundefined type.

Current and expected behavior

current:
undefined node is rebuilt

expected:
undefined node is updated

Environment

Rax Version: 1.2.2

build.json

No response

Possible solution

No response

Additional context

No response

Start in packages/rax/src/vdom/shouldUpdateComponent.js at the mentioned method and compare its handling of undefined with the linked null-node fix. Reproduce the UndefinedDemo example by toggling the button; done means an undefined child is updated rather than rebuilt.