Debugging with AI Assistance

Every developer has stared at a bug for hours, only to find it was a missing semicolon. Claude can dramatically speed up your debugging process - if you give it the right information.

The Debugging Prompt Formula

Language/Framework: [e.g., React 18 with TypeScript]
Error Message: [exact error text]
Expected Behavior: [what should happen]
Actual Behavior: [what actually happens]
Relevant Code: [the specific code involved]
What I've Tried: [your debugging attempts so far]

Stack Trace Analysis

When you get a stack trace, paste the entire thing:

Here's a stack trace from my Node.js application:

TypeError: Cannot read properties of undefined (reading 'id')
    at getUserProfile (/app/src/services/user.ts:42:28)
    at async handler (/app/src/routes/api/users.ts:15:20)

Here's the getUserProfile function:
[paste function code]

The error happens intermittently - maybe 1 in 10 requests.

Claude will analyze the trace, identify the likely cause (probably a race condition or missing null check), and suggest a fix.

Common Bug Patterns Claude Catches

Off-by-One Errors

// Bug: skips last element
for (let i = 0; i < array.length - 1; i++) { ... }
// Fix: should be i < array.length

Race Conditions

// Bug: data might not be loaded yet
const data = fetchData(); // async!
processData(data); // undefined

Type Coercion

// Bug: "5" + 3 = "53", not 8
const total = userInput + basePrice;

Null Reference

// Bug: user might be null
const name = user.profile.name;
// Fix: user?.profile?.name ?? 'Unknown'

The Rubber Duck Method, Upgraded

Explaining your bug to Claude is like rubber duck debugging, but the duck talks back:

I'm going to explain my bug to you step by step. 
After I'm done, tell me where my logic might be wrong.

Here's what the code is supposed to do: [explain]
Here's what it actually does: [explain]
Here's where I think the bug might be: [your theory]

Performance Debugging

This function takes 3 seconds to run with 1000 items:
[paste code]

Identify performance bottlenecks and suggest optimizations.
Show me the optimized version with explanations for each change.

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The fastest way to fix a bug is to understand it. Claude helps you understand faster.