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?
}).toErrorDev(
        'Received `true` for a non-boolean attribute `whatever`.\n\n' +
          'If you want to write it to the DOM, pass a string instead: ' +
          'whatever="true" or whatever={value.toString()}.',
      );
      expect(el.hasAttribute('whatever')).toBe(false);
    });
    it('assigns a numeric custom attributes as a string', function() {
      const el = ReactTestUtils.renderIntoDocument(<div whatever={3} />);
      expect(el.getAttribute('whatever')).toBe('3');
    });
    it('will not assign a function custom attributes', function() {
      let el;
      expect(() => {
        el = ReactTestUtils.renderIntoDocument(<div whatever={() => {}} />);
      }).toErrorDev('Warning: Invalid value for prop `whatever` on <div> tag');
      expect(el.hasAttribute('whatever')).toBe(false);
    });
    it('will assign an object custom attributes', function() {
      const el = ReactTestUtils.renderIntoDocument(<div whatever={{}} />);
      expect(el.getAttribute('whatever')).toBe('[object Object]');
    });
    it('allows Temporal-like objects as HTML (they are not coerced to strings first)', function() {
      class TemporalLike {
        valueOf() {
          
          
          throw new TypeError('prod message');
        }
        toString() {