Is it a good pattern to use !! notation to listen for ReactJS changes?

I've been adopting ReactJS + Redux in my projects for a couple of years. I often end up in asynchronous situations where I need my component to wait for the state to be updated to render. Normally the simple logic !this.props.isFetching ? <Component /> : "Loading..." is enough.

However there are cases where I need to check for the state of an array that is embedded in the state object. In these cases, most of my components end up looking like this:

  renderPostAuthor = () => {
    if (!!this.props.postDetails.author) {
      return this.props.postDetails.author[0].name;
    } else {
      return (
        <div>
          <StyledTitle variant="subheading" gutterBottom color="primary">
            Loading...
          </StyledTitle>
        </div>
      );
    }
  };

Is this use of the !! notation a good pattern / practice in ReactJS?