metamask-extension/ui/ducks/history/history.js

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

import { ASSET_ROUTE, DEFAULT_ROUTE } from '../../helpers/constants/routes';

// Constants

const initialState = {
  mostRecentOverviewPage: DEFAULT_ROUTE,
};

const name = 'history';

// Slice (reducer plus auto-generated actions and action creators)

const slice = createSlice({
  name,
  initialState,
  reducers: {
    pageChanged: (state, action) => {
      const path = action.payload;
      if (path === DEFAULT_ROUTE || path.startsWith(ASSET_ROUTE)) {
        state.mostRecentOverviewPage = path;
      }
    },
  },
});

const { actions, reducer } = slice;

export default reducer;

// Selectors

export const getMostRecentOverviewPage = (state) =>
  state[name].mostRecentOverviewPage;

// Actions / action-creators

export const { pageChanged } = actions;