How to use async reasonably in koa?

@dedrick 

In Koa, using async/await is a common practice to handle asynchronous operations. Here are some tips on how to use async/await reasonably in Koa:

1. Use async functions for route handlers: Instead of using callback functions, it's recommended to use async functions for route handlers. This makes the code more readable and manageable.
2. Handle errors properly: When using async functions, make sure to wrap the code in try/catch blocks to handle any errors that may occur during the asynchronous operation. You can also use Koa's built-in error handling middleware to centrally handle errors in your application.
3. Avoid nesting async functions: Try to avoid nesting multiple async functions within each other, as this can lead to callback hell and make the code harder to read and maintain. Instead, try to use async/await in a sequential manner.
4. Use Promise.all for concurrent async operations: If you need to perform multiple asynchronous operations concurrently, you can use Promise.all to wait for all promises to resolve before continuing with the rest of the code.
5. Consider using middleware for common tasks: If you find yourself repeating the same async operation in multiple route handlers, consider creating a custom middleware function to handle it, so you don't have to duplicate the code in every route.

Overall, using async/await in Koa can help you write cleaner and more maintainable code, but it's important to use it wisely and follow best practices to avoid common pitfalls.