How to Safely Execute Concurrent Promises in Node.js Without Blocking?

Executing Concurrent Promises in Node.js (ES7)

In asynchronous programming, it's often desirable to initiate tasks without waiting for their completion. However, concerns arise regarding error handling and the potential for unhandled rejections. Let's explore how to address these issues.

In your provided code snippet, the line redisClientAsync.delAsync('key'); returns a promise that is discarded without being awaited. This allows the function to continue executing without waiting for the asynchronous task to complete.

To handle such scenarios, consider the following options:

• Throwing Away the Promise:
  If you don't care about the result or exceptions thrown by the promise, simply discard it by not awaiting it. This method is quickest and appropriate if you want to run multiple asynchronous tasks concurrently without processing their outcomes. However, unhandled rejections can still crash your process.
• Ignoring Exceptions:
  If you don't care about exceptions but want to wait for the result, use .catch() to ignore the exception. This allows the function to continue without crashing.
• Chaining Promises:
  If you want to perform additional operations after the first asynchronous task completes, but don't need the result of the first task, use Promise.all() to chain the promises. This ensures both tasks execute concurrently, and the result of the second task is returned.
• Handling Exceptions Explicitly:
  If you care about exceptions and want to handle them manually, you can use Promise.all() and catch any exceptions within the .catch() block. This gives you control over exception handling and prevents unhandled rejections from crashing your process.

When executing asynchronous functions without awaiting them, it's essential to be aware of the potential for unhandled rejections and the implications for your application's stability. Carefully consider the options presented and choose the approach that best suits your specific requirements.

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