How to know if a function is async?

Question

I have to pass a function to another function, and execute it as a callback. The problem is that sometimes this function is async, like:

async function() {
          


        

Answer 1

You can assume at begin that callback is promise:

export async function runSyncOrAsync(callback: Function) {

  let promisOrValue = callback()
  if (promisOrValue instanceof Promise) {
    promisOrValue = Promise.resolve(promisOrValue)
  }
  return promisOrValue;
}

and them in your code you can do this:

await runSyncOrAsync(callback)

which will solve your problem with unknowing callback type....