减少非空 switch case 的数量

Question

有没有办法像 SonarQube 所说的那样减少非空开关案例的数量？ 在 reducer 文件中，a 在 switch 中有 37 个案例，但 SonarQube 只允许 30 个。

也许可以用不同的方式编写我的代码，因为它工作得很好，问题只是 SonarQube 像 CodeSmell 一样返回它。 我在下面发布了我的减速器代码。

export function equipmentReducer(
  lastState: IEquipmentState = new EquipmentState(),
  action: GenericAction<EquipmentActionTypes, any>
): IEquipmentState {
    switch (action.type) {
        case EquipmentActionTypes.REQUEST_EQUIPMENT:
          return reducerUtils.requestListData<IEquipmentState, IEquipment[]>(lastState, ['equipmentList']);

    case EquipmentActionTypes.RECEIVE_EQUIPMENT:
      return reducerUtils.receiveListData<IEquipmentState, IEquipment[]>(lastState, ['equipmentList'], action.payload);

    case EquipmentActionTypes.ERROR_RECEIVE_EQUIPMENT:
      return reducerUtils.errorListData<IEquipmentState, IEquipment[]>(lastState, ['equipmentList'], action.payload);

    case EquipmentActionTypes.REQUEST_EQUIPMENT_BY_ID:
      return reducerUtils.requestItemData<IEquipmentState, IEquipment>(lastState, ['selectedEquipment']);

    case EquipmentActionTypes.RECEIVE_EQUIPMENT_BY_ID:
      return reducerUtils.receiveItemData<IEquipmentState, IEquipment>(
        lastState,
        ['selectedEquipment'],
        action.payload as IEquipment
      );

    case EquipmentActionTypes.ERROR_RECEIVE_EQUIPMENT_BY_ID:
      return reducerUtils.errorItemData<IEquipmentState, IEquipment>(lastState, ['selectedEquipment'], action.payload);

    case EquipmentActionTypes.REQUEST_ADD_EQUIPMENT:
    case EquipmentActionTypes.REQUEST_UPDATE_EQUIPMENT:
      return reducerUtils.requestPostPutItemData<IEquipmentState, IEquipment>(
        lastState,
        ['selectedEquipment'],
        action.payload
      );

    case EquipmentActionTypes.RECEIVE_ADD_EQUIPMENT:
    case EquipmentActionTypes.RECEIVE_UPDATE_EQUIPMENT:
      return reducerUtils.receivePostPutItemData<IEquipmentState, IEquipment>(
        lastState,
        ['selectedEquipment'],
        action.payload
      );

    case EquipmentActionTypes.ERROR_ADD_EQUIPMENT:
    case EquipmentActionTypes.ERROR_UPDATE_EQUIPMENT:
      return reducerUtils.errorPostPutItemData<IEquipmentState, IEquipment>(
        lastState,
        ['selectedEquipment'],
        action.payload
      );

    case EquipmentActionTypes.REQUEST_INITIAL_SPECIFICATION:
      return reducerUtils.requestListData<IEquipmentState, IEquipmentInitialSpecification[]>(lastState, [
        'equipmentInitialSpecification',
      ]);

    case EquipmentActionTypes.RECEIVE_INITIAL_SPECIFICATION:
      return reducerUtils.receiveListData<IEquipmentState, IEquipmentInitialSpecification[]>(
        lastState,
        ['equipmentInitialSpecification'],
        action.payload
      );

    case EquipmentActionTypes.ERROR_INITIAL_SPECIFICATION:
      return reducerUtils.errorListData<IEquipmentState, IEquipmentInitialSpecification[]>(
        lastState,
        ['equipmentInitialSpecification'],
        action.payload
      );

    case EquipmentActionTypes.REQUEST_MANUFACTURERS:
      return reducerUtils.requestListData<IEquipmentState, IManufacturersListItem[]>(lastState, [
        'manufacturers',
        'manufacturerList',
      ]);

    case EquipmentActionTypes.RECEIVE_MANUFACTURERS:
      return reducerUtils.receiveListData<IEquipmentState, IManufacturersListItem[]>(
        lastState,
        ['manufacturers', 'manufacturerList'],
        action.payload
      );

    case EquipmentActionTypes.ERROR_RECEIVE_MANUFACTURERS:
      return reducerUtils.errorListData<IEquipmentState, IManufacturersListItem[]>(
        lastState,
        ['manufacturers', 'manufacturerList'],
        action.payload
      );

    case EquipmentActionTypes.REQUEST_SUPPLIERS:
      return reducerUtils.requestListData<IEquipmentState, ISuppliersListItem[]>(lastState, [
        'suppliers',
        'supplierList',
      ]);

    case EquipmentActionTypes.RECEIVE_SUPPLIERS:
      return reducerUtils.receiveListData<IEquipmentState, ISuppliersListItem[]>(
        lastState,
        ['suppliers', 'supplierList'],
        action.payload
      );

    case EquipmentActionTypes.ERROR_RECEIVE_SUPPLIERS:
      return reducerUtils.errorListData<IEquipmentState, ISuppliersListItem[]>(
        lastState,
        ['suppliers', 'supplierList'],
        action.payload
      );

    case EquipmentActionTypes.REQUEST_ADD_MANUFACTURER:
      return reducerUtils.requestPostPutItemData<IEquipmentState, IManufacturer>(
        lastState,
        ['manufacturers', 'selectedManufacturer', 'manufacturerInfo'],
        action.payload
      );

    case EquipmentActionTypes.RECEIVE_ADD_MANUFACTURER:
      return reducerUtils.receivePostPutItemData<IEquipmentState, IManufacturer>(
        lastState,
        ['manufacturers', 'selectedManufacturer', 'manufacturerInfo'],
        action.payload
      );

    case EquipmentActionTypes.ERROR_ADD_MANUFACTURER:
      return reducerUtils.errorPostPutItemData<IEquipmentState, IManufacturer>(
        lastState,
        ['manufacturers', 'selectedManufacturer', 'manufacturerInfo'],
        action.payload
      );

    case EquipmentActionTypes.REQUEST_ADD_SUPPLIER:
      return reducerUtils.requestPostPutItemData<IEquipmentState, ISupplier>(
        lastState,
        ['suppliers', 'selectedSupplier', 'supplierInfo'],
        action.payload
      );

    case EquipmentActionTypes.RECEIVE_ADD_SUPPLIER:
      return reducerUtils.receivePostPutItemData<IEquipmentState, ISupplier>(
        lastState,
        ['suppliers', 'selectedSupplier', 'supplierInfo'],
        action.payload
      );

    case EquipmentActionTypes.ERROR_ADD_SUPPLIER:
      return reducerUtils.errorPostPutItemData<IEquipmentState, ISupplier>(
        lastState,
        ['suppliers', 'selectedSupplier', 'supplierInfo'],
        action.payload
      );

    case EquipmentActionTypes.REQUEST_ADD_MANUFACTURER_CONTACT:
      return reducerUtils.requestPostPutItemData<IEquipmentState, IContact>(
        lastState,
        ['manufacturers', 'selectedManufacturer', 'selectedContact'],
        action.payload
      );

    case EquipmentActionTypes.RECEIVE_ADD_MANUFACTURER_CONTACT:
      return reducerUtils.receivePostPutItemData<IEquipmentState, IContact>(
        lastState,
        ['manufacturers', 'selectedManufacturer', 'selectedContact'],
        action.payload
      );

    case EquipmentActionTypes.ERROR_ADD_MANUFACTURER_CONTACT:
      return reducerUtils.errorPostPutItemData<IEquipmentState, IContact>(
        lastState,
        ['manufacturers', 'selectedManufacturer', 'selectedContact'],
        action.payload
      );

    case EquipmentActionTypes.REQUEST_ADD_SUPPLIER_CONTACT:
      return reducerUtils.requestPostPutItemData<IEquipmentState, IContact>(
        lastState,
        ['suppliers', 'selectedSupplier', 'selectedContact'],
        action.payload
      );

    case EquipmentActionTypes.RECEIVE_ADD_SUPPLIER_CONTACT:
      return reducerUtils.receivePostPutItemData<IEquipmentState, IContact>(
        lastState,
        ['suppliers', 'selectedSupplier', 'selectedContact'],
        action.payload
      );

    case EquipmentActionTypes.ERROR_ADD_SUPPLIER_CONTACT:
      return reducerUtils.errorPostPutItemData<IEquipmentState, IContact>(
        lastState,
        ['suppliers', 'selectedSupplier', 'selectedContact'],
        action.payload
      );

    case EquipmentActionTypes.REQUEST_EQUIPMENT_DELETE:
      return reducerUtils.requestPostPutItemData<IEquipmentState, IEquipment>(lastState, ['deletedEquipment'], action.payload);

    case EquipmentActionTypes.RECEIVE_EQUIPMENT_DELETE:
      return reducerUtils.receivePostPutItemData<IEquipmentState, IEquipment>(lastState, ['deletedEquipment'], action.payload);

    case EquipmentActionTypes.ERROR_RECEIVE_EQUIPMENT_DELETE:
      return reducerUtils.errorPostPutItemData<IEquipmentState, IEquipment>(lastState, ['deletedEquipment'], action.payload);

    case EquipmentActionTypes.REQUEST_EQUIPMENT_IS_DELETED:
      return requestItemData<IEquipmentState, boolean>(lastState, ['equipmentIsDeleted']);

    case EquipmentActionTypes.RECEIVE_EQUIPMENT_IS_DELETED:
      return receiveItemData<IEquipmentState, boolean>(lastState, ['equipmentIsDeleted'], action.payload);

    case EquipmentActionTypes.ERROR_RECEIVE_EQUIPMENT_IS_DELETED:
      return errorItemData<IEquipmentState, boolean>(lastState, ['equipmentIsDeleted'], action.payload);

    case EquipmentActionTypes.RESET_STATE:
      return resetSelectedEquipmentState(lastState);

    default:
      return lastState;
  }
}

Answer 1

我相信您可以通过找到共同的回报并创建一个 map 来减少它。例如， reducerUtils.requestListData被调用了 5 次，通过为差异创建一个 map，您应该能够摆脱 4 个开关案例。

最初的想法是将共享返回函数的action.types转换为新的 map ( myMap ) 键并在此处列出具体的不同参数（我使用option1和option2因为我不知道您的代码的 rest ）。 使用option1的另一种方法是将其更改为unknown或使用|的可能性列表。 ( IEquipment[] | IEq.... ) 里面<>

const myMap = {
    [EquipmentActionTypes.REQUEST_EQUIPMENT]: {
      option1: IEquipment[],
      option2: ['equipmentList']
    },
    [EquipmentActionTypes.REQUEST_INITIAL_SPECIFICATION]: {
      option1: IEquipmentInitialSpecification[],
      option2: ['equipmentInitialSpecification']
    },
    [EquipmentActionTypes.REQUEST_INITIAL_SPECIFICATION]: {
      option1: IEquipmentInitialSpecification[],
      option2: [
        'equipmentInitialSpecification',
      ]
    },
    [EquipmentActionTypes.REQUEST_MANUFACTURERS]: {
      option1: IManufacturersListItem[],
      option2: [
        'manufacturers',
        'manufacturerList',
      ]
    },
    [EquipmentActionTypes.REQUEST_SUPPLIERS]: {
      option1: ISuppliersListItem[],
      option2: [
        'suppliers',
        'supplierList',
      ]
    }
  }
  switch (action.type) {

    case EquipmentActionTypes.REQUEST_INITIAL_SPECIFICATION:
    case EquipmentActionTypes.REQUEST_MANUFACTURERS:
    case EquipmentActionTypes.REQUEST_SUPPLIERS:
    case EquipmentActionTypes.REQUEST_INITIAL_SPECIFICATION:
    case EquipmentActionTypes.REQUEST_EQUIPMENT:
      // alternatively instead of option1            ..... , unknown >
      // alternatively instead of option1            ..... , IEquipment[] | IEq.... >
      return reducerUtils.requestListData < IEquipmentState, myMap[action.type].option1 > (lastState, myMap[action.type].option2);

---

继续上面的想法，应该可以将option1移到选项 1 中并完全移除开关盒。 相关文章或这篇文章

const myMap = {
    [EquipmentActionTypes.REQUEST_EQUIPMENT]:{
        option1: reducerUtils.requestListData<IEquipmentState, IEquipment[] >(),
        option2: ['equipmentList']
    },
    ...
}
myMap[action.type].option1(lastState, myMap[action.type].option2, actionPayload)