testable-koa-next
A function that returns another function intended to be passed as next to Koa middleware functions under test conditions. Assertions can then be made about whether the middleware function waited for next to complete before returning.
Usage
const koaNext = createKoaNext();
await koaNext();
console.log(koaNext.didComplete)
const longerKoaNext = createKoaNext(100); 100ms
await longerKoaNext();
console.log(koaNext.didComplete)