javascript - 在 React Redux 中将之前的状态与新的状态进行比较

Question

如果声明与前一个相同，我想尝试不要传播"dispatch"。 我的“状态”始终包含默认值的问题。

const initialState = {
  pending: false,
  fetched: false,
  data: {
    playAndPayAllowed: false,
    sections: {},
    allowedSectionsCount: 0
  }
}

function isPreviousStateEqualToNew(oldState, newState) {
   return JSON.stringify(oldState) === JSON.stringify(newState);
}

export default function shopConfig(state = initialState, action) {
   switch (action.type) {
      case SHOP_CONFIG_PENDING:
        return {
            ...state,
            pending: true,
            data: {
                playAndPayAllowed: false,
                sections: {},
                allowedSectionsCount: 0
            },
            error: false
        }
     case SHOP_CONFIG_SUCCESS:
        if (isPreviousStateEqualToNew(state.data, action.payload)) {
            return;
        }

        const playAndPayAllowed = action.payload.playAndPayAllowed;
        const sections = action.payload.sections || [];
        const allowedSectionsCount = Object.values(sections).filter(item => item);

        return {
            ...state,
            pending: false,
            data: {
                playAndPayAllowed,
                sections: sections,
                allowedSectionsCount: allowedSectionsCount.length
            },
            error: false
        }
    default:
        return state;
}

}

期望在“state”变量中看到旧状态，但“state”始终等于“initialState”。

Answer 1

我不明白问题出在哪里，或者我弄错了，只需返回未更改的状态:

if (isPreviousStateEqualToNew(state.data, action.payload)) {
            return state;
        }