[haukur]

It does, you can write this with a Babel preset supporting this feature:

    class Foo extends Component {
      state = {
        foo: '',
      };

      // The arrow function here is what you're looking for.
      onChange = ({ target }) => {
        this.setState({
          // You can of course use `foo` directly as the key if you just have the one input.
          [target.name]: target.value,
        });
      };
    
      render () {
        return <input type="text" name="foo" value={this.state.foo.value} onChange={this.onChange} />;
      }
    }

[dmitriid]

Then either the readme in the proposal is wrong or the unknown babel preset is wrong

Also, your example is not equivalent to either the complaint in the original comment or to the code snippet I quoted

Also: React has been binding event handlers to `this` since forever without presets (update: only in React.creatClass though)

[danabramov]

The proposal README is written for TC39 and not React users, so it doesn't address the problems React users face.

Yes, with public fields you can write

    handleClick = () => {
      // ...
    }

and it works like if you bound it in the constructor.

Hope this helps.

[dmitriid]

It’s not just React-specific. I was correct: the proposal does exactly nothing to make sure class methods are bound to class instances.

  handleClick = () => {...}

This is a shitty workaround that abuses class fields and arrow functions