with callback...

//container
const mapDispatchToProps=(dispatch)=>{
  return {
    createComment: async (trackId, commentText, cb)=>{
      dispatch(createCommentAction(trackId, commentText)).then(cb);
    }
  }
}

//Component
this.props.createComment(this.props.trackId, this.state.newComment, this.clearFormState);

clearFormState(){
  this.setState({
    newComment: '',
    loading: false
  })
}