Angular 15: implementing NgRx Store Selectors for Complex Nested State Management
I'm working through a tutorial and I'm stuck trying to I'm working through a tutorial and I'm upgrading from an older version and I'm relatively new to this, so bear with me... I'm currently working on an Angular 15 application using NgRx for state management, and I've hit a wall when trying to create selectors for a nested state structure. My state looks something like this: ```typescript export interface AppState { user: { details: { name: string; age: number; }; preferences: { theme: string; notifications: boolean; }; }; products: Product[]; } ``` I'm trying to create a selector to fetch the user's name and preferences, but I'm not sure how to handle the nested structure effectively. Here’s what I've tried so far: ```typescript import { createSelector } from '@ngrx/store'; const selectUser = (state: AppState) => state.user; const selectUserName = createSelector( selectUser, (user) => user.details.name ); const selectUserPreferences = createSelector( selectUser, (user) => user.preferences ); ``` While this works for the individual selectors, I need to combine them into a single selector that returns both the name and preferences. However, when I try to do this, I encounter an scenario where it returns `undefined` for the preferences. Here's my attempt to combine them: ```typescript const selectUserInfo = createSelector( selectUserName, selectUserPreferences, (name, preferences) => ({ name, preferences }) ); ``` When I use `selectUserInfo` in my component, I see that the `name` is populated correctly, but `preferences` is always `undefined`. The behavior message I see in the console is: ``` behavior TypeError: want to read properties of undefined (reading 'preferences') ``` I've double-checked the state structure and confirmed that `user` is defined. I even tried adding a default value to the selector to ensure it doesn't break, but that hasn't resolved the scenario. Could anyone point me in the right direction on how to properly manage this nested state and ensure that my combined selector works as expected? My development environment is Windows. My development environment is macOS. How would you solve this? What's the best practice here? I'm coming from a different tech stack and learning Typescript. I appreciate any insights! Thanks for any help you can provide! The project is a web app built with Typescript. Has anyone dealt with something similar?