TypeScript Version:

• 2.2.0-dev.20161113 (Not version specific)
• target = esnext, jsx = preserve

Description
I expect Typescript to more or less only strip types but preserve the rest - based on the target compilerOption. Especially when using a target like es2017 or even esnext.

Class-properties are always moved into the constructor. This prevents hot-reloading of class-property functions when using react-hot-loader 3.

Using them is a common pattern for binding event-handler functions to this without having to do this for every method in the constructor.

Code

class MyClass {
  prop1: number = 123;
  handleClick = () => {
    console.log('Click handled');
  }
  render() {
    return <button onClick={this.handleClick}>Click me</button>;
  }
}

Expected emit:

class MyClass {
  prop1 = 123;
  handleClick = () => {
    console.log('Click handled');
  }
  render() {
    return <button onClick={this.handleClick}>Click me</button>;
  }
}

Actual emit:

class MyClass {
  constructor() {
    super(...arguments);
    this.prop1 = 123;
    this.handleClick = () => {
      console.log('Click handled');
    };
  }
  render() {
    return <button onClick={this.handleClick}>Click me</button>;
  }
}