如何在 redux-toolkit 中正确使用 PayloadAction 和元类型？

Question

简化示例

import { createSlice, PayloadAction } from '@reduxjs/toolkit';

    type Cake = {
      flavor: string;
      size: 'S' | 'M' | 'L';
    };

const initialState: { all: Cake[]; meta: { currentPage: number } } = {
  all: [],
  meta: {
    currentPage: 0,
  },
};

const cakeSlice = createSlice({
  name: 'cake',
  initialState,
  reducers: {
    fetchAll(
      state,
      action: PayloadAction<Cake[], string, { currentPage: number }>,
    ) {
      state.all = action.payload;
      state.meta = action.meta;
    },
  },
});

export default cakeSlice;

我收到这些错误。

Type '
(state: {
    all: {
        flavor: string;size: "S" | "M" | "L";
    } [];meta: {
        currentPage: number;
    };
}, action: PayloadAction < Cake[], string, {
    currentPage: number;
}, never > ) => void ' is not assignable to type '
CaseReducer < {
    all: Cake[];meta: {
        currentPage: number;
    };
}, {
    payload: any;type: string;
} > | CaseReducerWithPrepare < {
    all: Cake[];meta: {
        currentPage: number;
    };
}, {
    payload: any;type: string;
} > '

Type '
(state: {
    all: {
        flavor: string;size: "S" | "M" | "L";
    } [];meta: {
        currentPage: number;
    };
}, action: PayloadAction < Cake[], string, {
    currentPage: number;
}, never > ) => void '
is not assignable to type 'CaseReducer<{ all: Cake[]; meta: { currentPage: number; }; }, { payload: any; type: string; }>'.
Types of parameters 'action'
and 'action'
are incompatible.
Type '{ payload: any; type: string; }'
is not assignable to type 'PayloadAction<Cake[], string, { currentPage: number; }, never>'.
Property 'meta'
is missing in type '{ payload: any; type: string; }'
but required in type '{ meta: { currentPage: number; }; }
'.

Answer 1

RTK 的默认行为是创建一个仅具有一个参数和一个有效负载属性的操作创建器。此行为无法通过 TS 注释进行修改，因为 TS 注释对运行时行为没有影响。

您可以使用该prepare符号来定义覆盖此默认行为的函数。prepare该函数与 createAction 的参数具有相同的签名和行为，因此您可以在那里找到大多数相关文档。

在您的具体情况下，您需要类似的东西

const cakeSlice = createSlice({
  name: 'cake',
  initialState,
  reducers: {
    fetchAll: {
      reducer(
        state,
        action: PayloadAction<Cake[], string, { currentPage: number }>
      ) {
        state.all = action.payload
        state.meta = action.meta
      },
      prepare(payload: Cake[], currentPage: number) {
        return { payload, meta: { currentPage } }
      }
    }
  }
})

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