Resolving State Problems for an Instagram Clone in React with Zustand

Managing Post Counts in Your Zustand-Powered Instagram Clone

Imagine you’ve just finished building a feature for your Instagram clone where users can create posts, and the number of posts displays prominently on their profile. 🎉 You’re feeling proud as everything seems to be working—until it doesn’t. After deleting some posts, the post count on the user’s profile still doesn’t update correctly. This can be a frustrating issue for any developer.

In the scenario described, you’ve built a state management solution using Zustand. While it handles adding and deleting posts efficiently, the persistent memory of previously created posts introduces a bug. Specifically, the global state retains old values, leading to an inflated post count even when fewer posts exist. A misstep like this can break the user experience.

This challenge of resetting a global state is not uncommon in React apps. Zustand’s simplicity and minimal boilerplate make it a great choice for state management. However, when resetting state isn’t optimized, performance hiccups, like slow loading times on the profile page, can arise. 🚀 Tackling this issue requires understanding state updates and efficient retrieval methods.

In this article, we’ll walk you through the root cause of this issue and propose an effective way to reset your global state without sacrificing performance. Along the way, we’ll explore how to maintain a seamless user experience, even in complex state-driven applications. Let’s dive in! 🛠️

Optimizing State Management in a React Instagram Clone

The scripts above address the issue of managing and resetting a global state in a React application using Zustand. Zustand is a minimalist state management library that provides a simple API for handling application states without unnecessary complexity. In this context, the primary problem lies in the persistent memory of old posts in the state, causing inaccuracies in the post count displayed on the user's profile. To tackle this, we created a resetPosts function within the Zustand store to clear the state and ensure an accurate post count. This method effectively eliminates outdated data while maintaining the user interface's responsiveness. 🎯

One of the key features of the script is the addPost function, which dynamically updates the state by appending new posts to the current list. This functionality ensures that every new post a user creates is reflected immediately on their profile. Similarly, the deletePost function enables the removal of a post by filtering the state array based on the post ID. Together, these functions ensure seamless interaction for users as they create and delete posts, maintaining an up-to-date state representation.

The second script, useGetUserPosts, is a custom hook that fetches user-specific posts from Firestore. This hook is triggered whenever the user profile changes, ensuring that the state is always in sync with the backend. The script leverages Firestore commands like query, where, and getDocs to fetch relevant posts. Sorting the posts by creation date ensures that the most recent entries appear first, which enhances the user experience by showing the latest content on top.

Lastly, the inclusion of unit tests using Jest highlights the importance of validating the solution across different environments. By testing functions like resetPosts, we ensure that the implementation works as expected and handles edge cases effectively. For instance, a test simulates adding posts, resetting the state, and verifying that the posts array is empty. These tests serve as a safety net, preventing regressions as the application evolves. With optimized methods and robust testing, this solution provides a scalable way to manage global state in a React application. 🚀

// Zustand store with a resetPosts function for resetting state
import { create } from "zustand";
const useUserProfileStore = create((set) => ({
  userProfile: null,
  setUserProfile: (userProfile) => set({ userProfile }),
  addPost: (post) =>
    set((state) => ({
      userProfile: {
        ...state.userProfile,
        posts: [post.id, ...(state.userProfile?.posts || [])],
      },
    })),
  deletePost: (id) =>
    set((state) => ({
      userProfile: {
        ...state.userProfile,
        posts: state.userProfile.posts.filter((postId) => postId !== id),
      },
    })),
  resetPosts: () =>
    set((state) => ({
      userProfile: {
        ...state.userProfile,
        posts: [],
      },
    })),
}));
export default useUserProfileStore;

import { useEffect, useState } from "react";
import useUserProfileStore from "../store/userProfileStore";
import { collection, getDocs, query, where } from "firebase/firestore";
import { firestore } from "../Firebase/firebase";
const useGetUserPosts = () => {
  const { userProfile, resetPosts } = useUserProfileStore();
  const [posts, setPosts] = useState([]);
  const [isLoading, setIsLoading] = useState(true);
  useEffect(() => {
    const fetchPosts = async () => {
      if (!userProfile) return;
      try {
        const q = query(
          collection(firestore, "posts"),
          where("createdBy", "==", userProfile.uid)
        );
        const snapshot = await getDocs(q);
        const fetchedPosts = snapshot.docs.map((doc) => ({ id: doc.id, ...doc.data() }));
        fetchedPosts.sort((a, b) => b.createdAt - a.createdAt);
        setPosts(fetchedPosts);
      } catch (error) {
        console.error("Error fetching posts:", error);
        resetPosts();
      } finally {
        setIsLoading(false);
      }
    };
    fetchPosts();
  }, [userProfile, resetPosts]);
  return { posts, isLoading };
};
export default useGetUserPosts;

import useUserProfileStore from "../store/userProfileStore";
describe("UserProfileStore", () => {
  it("should reset posts correctly", () => {
    const { resetPosts, addPost, userProfile } = useUserProfileStore.getState();
    addPost({ id: "1" });
    addPost({ id: "2" });
    resetPosts();
    expect(userProfile.posts).toEqual([]);
  });
});

Effective State Management with Zustand for React Applications

One critical aspect of managing global state in applications like an Instagram clone is ensuring the state is accurate and up to date. Zustand’s simple and efficient approach to state management allows developers to define custom actions, such as resetting or updating state variables, while keeping the code clean and readable. For instance, the resetPosts function we created clears outdated post data from the state, ensuring users see the correct post count on their profiles. This function exemplifies Zustand’s flexibility in addressing issues tied to dynamic data updates. 🚀

Another often overlooked aspect is how the interaction between frontend and backend impacts performance. While resetting state locally can address some issues, ensuring the synchronization of the frontend state with backend data (like from Firestore) is crucial. Using Firestore commands like getDocs and query allows fetching user-specific posts efficiently. Additionally, features like sorting posts by createdAt help deliver a user-friendly interface by presenting the most recent data first. For instance, if a user publishes a new post, it will appear at the top of their feed, offering instant feedback. 😊

Lastly, modularity is an essential design principle. By separating state logic into a Zustand store and fetching logic into a custom React hook, you create reusable components that are easy to maintain and test. This approach not only simplifies debugging but also enhances scalability as new features are added. Combining these best practices with robust testing ensures the app delivers a seamless and reliable experience, even under complex scenarios. Such considerations are vital for modern web applications.