`@typescript-eslint/no-misused-promises` with async listener

[UnsungHero97]

We've established that listeners can be async but I think the listener type might be wrong:

const interceptor = new XMLHttpRequestInterceptor();
interceptor.on('request', async ({ controller, request }) => {
  const response = await getResponse(handlers, request);
  controller.respondWith(response ?? Response.json({ error: 'msw interceptor error' }));
});

ESlint is not happy with the async listener:

/Users/hristo/dev/msw-interceptors-listener-type/src/main.tsx
  13:27  error  Promise returned in function argument where a void return was expected  @typescript-eslint/no-misused-promises

✖ 1 problem (1 error, 0 warnings)

Here's a repo to reproduce the issue:

https://github.com/UnsungHero97/msw-interceptors-listener-type

This might be a type issue in strict-event-emitter but I'm seeing it by using XMLHttpRequestInterceptor.

[kettanaito]

Hi, @UnsungHero97. Thanks for reporting this.

I think you're right, strict-event-emitter annotates the return type of listener as void, which might confuse the linter:

https://github.com/open-draft/strict-event-emitter/blob/c0c3d5a1f942da9e1fa16f0d36565a75839dae78/src/Emitter.ts#L13

Interestingly enough, the type inference works as expected in TypeScript itself. I'd fix this by migrating from strict-event-emitter to rettime, which is the recent iteration of strict events.