When setting boolean attributes on Web Components
`<x-search somebool name={this.props.name} />`
they get rendered as attribute/value pairs instead
`<x-search somebool="true" name={this.props.name}>`

This causes problems with some AMP components, for eg. `<amp-iframe />` which has a `resizable` attribute that gets rendered as `resizable="true"`. This results in non valid AMP content and developers crying with blood tears on their keyboards :)
> The attribute 'resizable' in tag 'amp-iframe' is set to the invalid value 'true'. (see https://www.ampproject.org/docs/reference/components/amp-iframe)

Is there any reason for the current behaviour? Will changing this break something else?
customelement.dispatchEvent(new Event('customevent'));
      expect(oncustomevent).toHaveBeenCalledTimes(2);
      expect(customelement.oncustomevent).toBe(undefined);
      expect(customelement.getAttribute('oncustomevent')).toBe(null);
    });
    
    it('custom element custom event handlers assign multiple types with setter', () => {
      const container = document.createElement('div');
      document.body.appendChild(container);
      const oncustomevent = jest.fn();
      
      ReactDOM.render(<my-custom-element />, container);
      const customelement = container.querySelector('my-custom-element');
      
      Object.defineProperty(customelement, 'oncustomevent', {
        set: function(x) {
          this._oncustomevent = x;
        },
        get: function() {
          return this._oncustomevent;
        },
      });
      expect(customelement.oncustomevent).toBe(undefined);
      
      ReactDOM.render(
        <my-custom-element oncustomevent={oncustomevent} />,
        container,
      );
      customelement.dispatchEvent(new Event('customevent'));
      expect(oncustomevent).toHaveBeenCalledTimes(1);