StepFunctions: Promise.all(array.map) should be parallel

[sam-goodwin]

The following common pattern os using Promise.all and array.map(Promise) does not use a Parallel state. It should.

Doing this generally would be difficult (maybe impossible) without type information. Perhaps we can implement a heuristic to detect this pattern.

new StepFunction(
  stack,
  "SendMessageBatch",
  async (input: { messages: OrderPlacedEvent[] }) => {
    await Promise.all(
      input.messages.map(async (message) => {
        await orderQueue.sendMessage({
          MessageBody: message,
        });
      })
    );
  }
);

[thantos]

The pattern with Promise.All to represent map which contains async statements was a mistake, the same goes for AppSync, however, we do need a way to represent a [].map which contains integrations, unless we want to say that is only possible with $SFN.map with concurrency 1.

[sam-goodwin]

I don't understand, what was a mistake?