Function reducer

test/index.spec.js:238–249

(state = initialState, action)

        fourthRun: false,
      };
      const reducer = (state = initialState, action) => {
        switch (action.type) {
          case 'FIRST_ACTION':
            return loop(state, Cmd.run(thunk, { args: [Cmd.dispatch] }));

          case 'DOWNSTREAM_ACTION':
            return { ...state, secondRun: true };

          default:
            return state;
        }
      };
      const store = createStore(reducer, initialState, install());

      store.dispatch(firstAction).then((result) => {