Dev Tools evolved a lot the last months.

Last version doesn't display well functions in props, it leaves an empty field so hard to see if the prop is really passed and if there's really and function passes in the props of the component.

For example  i dont' know if the prop `onChange` really exists as a prop of the component `TokenInput`.
Don't know also which props are undefined.

Could be also great to use the propTypes to show the types of the props.

![image](https://user-images.githubusercontent.com/25119847/71781247-b5e8fb00-2fcc-11ea-9a08-86f7b772a138.png)


![image](https://user-images.githubusercontent.com/25119847/71781235-8c2fd400-2fcc-11ea-8c3f-fb0afe3ab8fc.png)

if (typeof type === 'string') {
        return type;
      } else if (type != null) {
        return getDisplayName(type, 'Anonymous');
      } else {
        return 'Element';
      }
  }
}
const MAX_PREVIEW_STRING_LENGTH = 50;
function truncateForDisplay(
  string: string,
  length: number = MAX_PREVIEW_STRING_LENGTH,
) {
  if (string.length > length) {
    return string.substr(0, length) + '…';
  } else {
    return string;
  }
}
 Attempts to mimic Chrome's inline preview for values.
 For example, the following value...
   {
      foo: 123,
      bar: "abc",
      baz: [true, false],
      qux: { ab: 1, cd: 2 }
   };
 Would show a preview of...
   {foo: 123, bar: "abc", baz: Array(2), qux: {…}}