Function lawsOf

lawsOf<
    M extends Functor<number, M> & Monad<number, M>,
    VERDICT extends void | Promise<void>,
>(
    unit: (value: number) => M,
    eq: (left: M, right: M) => VERDICT,
): {
    associativity: (m: M) => VERDICT;
    leftIdentity: () => VERDICT;
    mapComposition: (m: M) => VERDICT;
    mapIdentity: (m: M) => VERDICT;
    rightIdentity: (m: M) => VERDICT;
}
The law harness: hand it your type's unit and an equality, get back the functor and monad laws as runnable assertions. The constraint is the entry fee — your type must already be the capabilities it claims. The shipped containers prove themselves with it in their own suites; a type you mint yourself proves its laws the same way.
```
const laws = lawsOf<Mine, void>(mine, (left, right) => expect(left.value).toEqual(right.value));
laws.leftIdentity();
laws.rightIdentity(mine(3));
laws.associativity(mine(3));
laws.mapIdentity(mine(3));
laws.mapComposition(mine(3));
```
Type Parameters
- M extends Functor<number, M> & Monad<number, M>
- VERDICT extends void | Promise<void>
Parameters
- unit: (value: number) => M
- eq: (left: M, right: M) => VERDICT
Returns {
    associativity: (m: M) => VERDICT;
    leftIdentity: () => VERDICT;
    mapComposition: (m: M) => VERDICT;
    mapIdentity: (m: M) => VERDICT;
    rightIdentity: (m: M) => VERDICT;
}
- Defined in laws.ts:19