Is Using Async/Await in a Promise Constructor an Anti-Pattern?

Is It an Anti-Pattern to Use async/await in a Promise Constructor?

In asynchronous programming, the Promise constructor is used to create a new Promise object. A common debated practice is using async/await within the Promise constructor's executor function.

Understanding the Anti-Pattern

Using async/await inside a Promise constructor is considered an anti-pattern due to the following risks:

• Error Handling: Errors thrown within the async/await block may not be correctly propagated to the outer Promise. Thus, unhandled errors could occur.
• Performance: Asynchronous operations within a Promise constructor can delay the resolution of the Promise, which can negatively impact performance.

Example

Consider the following code:

function myFunction() {
  return new Promise(async (resolve, reject) => {
    // Using async/await within Promise constructor
  });
}

In this example, the use of async/await can lead to error handling issues. If an exception occurs within the async block, it may not be properly propagated to the outer Promise, resulting in potential unhandled errors.

Best Practices

To avoid the risks associated with this anti-pattern, it's recommended to refrain from using async/await within Promise constructors. Instead, consider using alternative approaches such as wrapping asynchronous operations in separate Promises and chaining them together. This ensures proper error handling and maintains performance.

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