AwaitAll will take a slice of inputs and will inject the input into the async func to run in parallel with the other inputs. Then function will wait until all of the responses are done and will return them in the same order of the inputs. The async function cannot throw an error and must return the error in the response.

awaitall.go

func AwaitAll[Input any, Response any](sliceOfInputs []Input, asyncFunc func(Input) Response) []Response {
	responses := make([]Response, len(sliceOfInputs))

	var waitGroup sync.WaitGroup

	for i, input := range sliceOfInputs {
		waitGroup.Add(1)
		go func(i int, input Input) {
			responses[i] = asyncFunc(input)
			waitGroup.Done()
		}(i, input)
	}

	waitGroup.Wait()

	return responses
}