# caseOnly

`import { caseOnly } from "destack:fuzz";`

Register one focused fuzz case.

```ds title="caseOnly"
export function caseOnly<T>(name: string, generator: Generator<T>, body?: Body<T> | undefined): void
```

[language/library/src/fuzz/case.ds:55:57](https://github.com/destack-sh/destack/blob/main/language/library/src/fuzz/case.ds#L55-L57)