Function reducer

tests/select.test.ts:102–145

(state: State, event: Event)

    };

    const reducer = (state: State, event: Event): State =>
      match<[State, Event], State>([state, event])
        .with(
          [
            { status: 'loading' },
            {
              type: 'success',
              data: P.select('data'),
              requestTime: P.select('time'),
            },
          ],
          ({ data, time }) => {
            type t = Expect<Equal<typeof time, number | undefined>>;

            return {
              status: 'success',
              data,
            };
          }
        )
        .with(
          [{ status: 'loading' }, { type: 'success', data: P.select('data') }],
          ({ data }) => ({
            status: 'success',
            data,
          })
        )
        .with(
          [{ status: 'loading' }, { type: 'error', error: P.select('error') }],
          ({ error }) => ({
            status: 'error',
            error,
          })
        )
        .with([{ status: 'loading' }, { type: 'cancel' }], () => initState)
        .with([{ status: P.not('loading') }, { type: 'fetch' }], () => ({
          status: 'loading',
        }))
        .with([P.select('state'), P.select('event')], ({ state, event }) => {
          type t = Expect<Equal<typeof state, State>>;
          type t2 = Expect<Equal<typeof event, Event>>;
          return state;
        })
        .run();

    expect(reducer(initState, { type: 'cancel' })).toEqual(initState);