Resolving Endless Loops in a Cryptocurrency Token Application

Introduction

Hello wonderful readers! 👋 Today, I wanted to share a recent debugging adventure I embarked on while working on a crypto token app. Debugging challenges often lead to some of the most valuable learning experiences, so let's dive right in!

The Challenge: Infinite Looping

The issue I encountered was an unexpected infinite loop during the fetching and updating of token data. Every time I tried to fetch or update the data, it seemed to trigger another fetch or update, creating an endless loop.

The Solution: Optimizing with mutate and State Management

Optimizing mutate Usage

One of the main issues was the excessive use of mutate from the SWR library. I noticed that I was causing unnecessary re-renders by using mutate too often.

To improve this, I adjusted the configurations of the useSWR hook and managed when mutate was invoked to make sure it only revalidated when necessary.

// Previous useSWR configuration
useSWR("getUserTokens", fetchUserTokens);

// Optimized useSWR configuration
useSWR("getUserTokens", fetchUserTokens, { revalidateIfStale: true });

Improving State Updates Post-Async Operations

Another issue I faced was handling the state after asynchronous operations. I made sure to update the state correctly after fetching and updating token data.

Here's a snippet showing how I updated the state after fetching user tokens:

const fetchUserTokens = async () => {
  try {
    const tokens = await getTokens(userId);
    setUserTokensLoading(false);
    return tokens;
  } catch (error) {
    console.error("Error fetching user tokens:", error);
    throw error;
  }
};

Key Takeaways

• Use mutate judiciously: Avoid unnecessary re-renders by controlling when mutate is called.

• State management post-async: Ensure correct state management after asynchronous operations to prevent unexpected behavior.

Conclusion

Debugging can be challenging but also incredibly rewarding. This experience taught me the importance of careful optimization and state management in React apps, especially when working with libraries like SWR.

Approach debugging challenges with curiosity and patience, and remember, every issue is an opportunity to learn and grow! 🌱