# rollup.run

Convenience request loop: repeatedly [`finish`](/cmio/reference/finish)es the previous request and dispatches the next one to your handlers.

## Usage

```ts twoslash
import { Rollup } from '@deroll/cmio';

const rollup = new Rollup();

await rollup.run({
    advance(request, rollup) {
        rollup.emitNotice(request.payload);
        return true;
    },
    inspect(request, rollup) {
        rollup.emitReport(request.payload);
    },
});
```

## Returns

`Promise<never>` — the loop runs until `finish` fails (inputs exhausted on the mock, or device closed), and the promise rejects with that error. It never resolves.

## Parameters

### handlers

* Type: `RunHandlers`

An object with an optional handler per request type. Both receive `(request, rollup)` and may be synchronous or `async`:

```ts twoslash
import type { AdvanceRequest, InspectRequest, Rollup } from '@deroll/cmio';
// ---cut---
type RunHandlers = {
    advance?: (
        request: AdvanceRequest,
        rollup: Rollup,
    ) => boolean | void | Promise<boolean | void>;
    inspect?: (
        request: InspectRequest,
        rollup: Rollup,
    ) => boolean | void | Promise<boolean | void>;
};
```

The handler's result decides the request's fate:

| Handler outcome | Effect |
| --- | --- |
| returns `true` or `undefined` | request **accepted** |
| returns `false` | request **rejected** |
| throws | exception emitted as a [report](/cmio/reference/emit-report), request **rejected** |
| no handler for the request type | request **rejected** |

See [Handling Requests](/cmio/guide/handling-requests) for the semantics of accept/reject.