Failed to add new elements when set initialState as an empty object - redux-toolkit

Question

I try to use redux toolkit and I have this as menu-slice.js
I try to use property accessors to add a new property to fileItems, its initial value is an empty object.
import { createSlice } from "#reduxjs/toolkit";
const menuSlice = createSlice({
name: "ui",
initialState: {
fileItems: {},
},
reducers: {
setFileDate: (state, action) => {
state.FileDate = action.payload;
},
replaceFileItems: (state, action) => {
const filesList = action.payload.map((fileName) =>
fileName.slice(fileName.indexOf("/") + 1)
);
state.fileItems[state.FileDate] = filesList;
console.log(`filesList: ${filesList}`);
console.log(`state.fileItems: ${JSON.stringify(state.fileItems)}`);
console.log(`state.FileDate: ${state.FileDate}`);
state.fileContents = null;
},
I call dispatch with the api return value ( dispatch(menuActions.replaceFileItems(fileResponse.data));)
in menu-action.js:
the return value is an array of strings.
export const fetchFiles = (fileDate) => {
return async (dispatch) => {
const fetchFilesList = async () => {
const response = await fetch(
"some url" +
new URLSearchParams({
env: "https://env.com",
date: fileDate,
})
);
if (!response.ok) {
throw new Error("Fail to fetch files list!");
}
const data = await response.json();
return data;
};
try {
const fileResponse = await fetchFilesList();
dispatch(menuActions.setFileDate(FileDate));
dispatch(menuActions.replaceFileItems(fileResponse.data));
} catch (error) {
dispatch(
menuActions.showNotification({....
})
);
}
};
};
But it never prints console logs and didn't display where went wrong in the console or in the chrome redux extension.
I want to add data into state.fileItems on each click that triggers fetchFiles() when it returns a new array:
from state.fileItems = {}
check if state.fileItems already has the date as key,
if not already has the date as key,
change to ex: state.fileItems = {"2022-01-01": Array(2)}
and so on..
ex: state.fileItems = { "2022-01-01": Array(2), "2022-01-02": Array(2) }
I also tried to set state.fileItems as an empty array, and use push, but it didn't work either, nothing printed out, state.fileItems value was always undefined.
Can anyone please tell me why this didn't work?
Thanks for your time to read my question.