How do I prevent unhandled promise rejections in Vue.js?

To prevent unhandled promise rejections in Vue.js, use `.catch()` on all promises to handle potential rejections. Additionally, use `try...catch` blocks within `async/await` functions to catch errors. Vue also provides a global error handler that can catch unhandled promise rejections and display a generic error message to the user. This is configured using the `error.stack` option in `vue.config.js` or within the Vue instance configuration. Consider using a library like `express-promise-handler` for Express.js applications to handle promise rejections more effectively.