Make defaultProps static

[selvagsz]

FEATURE REQUEST / CODE CHANGE

• I have deleted the BUG REPORT section

Summary

Migrate the instance.getDefaultProps() to static Klass.defaultProps

Motivation

1. Stays more in alignment with the inspired react apis
2. I don't think we should rely on instance for providing default values for a component
3. I'd personally prefer composition over inheritance.
4. The static syntax looks more obvious & cleaner than the getDefaultProps hook. Can be separated from the implementation if required which opens up more space for docs generation

Detailed design

import Component from '@ember/component';

const AlertBox = Component.extend({
  //
});

AlertBox.propTypes = {
  type: PropTypes.oneOf(['warning', 'info', 'error', 'success']),
  dismissible: PropTypes.bool,
};

AlertBox.defaultProps = {
  type: 'warning',
  dismissible: true,
};

export default AlertBox;

How we teach this

This change would be breaking in two aspects

1. removing the inheritance support (invoking _super via concatenated prop)
2. no this context while providing the defaultProps

So, a major version bump would be my call

Alternatives

• Leave as it is

[selvagsz]

I can help with a PR if accepted