Complex bugs often hide in the interactions between different parts of your system, making them difficult to spot through traditional debugging methods. The Oracle excels at systematically analyzing code paths, identifying issues that may only surface under specific conditions or involve subtle logic errors.
This guide demonstrates how to use the Oracle to identify and resolve a complex bug that only appears under specific circumstances.
Our example: Task API with intermittent failures
Imagine that we have a task management API, and we've been getting reports of intermittent failures when users try to complete tasks. The bug occurs only occasionally and appears to be related to concurrent usage. Here's the task completion logic that's causing issues:
// server.js \- Task completion with a subtle bug
let tasks \= \[\];
let completedCount \= 0;
app.patch('/tasks/:id/complete', async (req, res) \=\> {
const taskId \= parseInt(req.params.id);
const task \= tasks.find(t \=\> t.id \=== taskId);
if (\!task) {
return res.status(404).json({ error: 'Task not found' });
}
if (task.completed) {
return res.status(409).json({ error: 'Task already completed' });
}
// Update task status
task.completed \= true;
task.completedAt \= new Date().toISOString();
// Send notification (async operation)
sendNotification(task.userId, \`Task "${task.title}" completed\`);
// Update global counter
completedCount++;
// Update user's completion streak
await updateUserStreak(task.userId);
res.json(task);
});
async function updateUserStreak(userId) {
const userTasks \= tasks.filter(t \=\> t.userId \=== userId && t.completed);
const user \= await getUserById(userId);
// Calculate streak: consecutive days with completed tasks
const today \= new Date().toDateString();
const yesterday \= new Date(Date.now() \- 86400000).toDateString();
const todayTasks \= userTasks.filter(t \=\>
new Date(t.completedAt).toDateString() \=== today
);
const yesterdayTasks \= userTasks.filter(t \=\>
new Date(t.completedAt).toDateString() \=== yesterday
);
if (todayTasks.length \> 0\) {
if (yesterdayTasks.length \> 0 || user.currentStreak \=== 0\) {
user.currentStreak \= (user.currentStreak || 0\) \+ 1;
}
}
await saveUser(user);
}
The problem: Inconsistent user streaks
Users are reporting that their task completion streaks are sometimes incorrect - they complete tasks every day, but their streak counter resets unexpectedly or displays incorrect numbers. The issue occurs more frequently when multiple users attempt to complete tasks simultaneously. Let's use the Oracle to analyze the task completion logic. Here's our prompt to Amp that will invoke the Oracle to check this out:
I have a bug where user completion streaks are getting calculated incorrectly when users complete tasks. The streak counter sometimes resets to the wrong values or doesn't increment properly. This seems to happen more during peak usage times when multiple users are completing tasks simultaneously. Use the oracle to analyze the task completion logic and identify potential race conditions or logic errors that could cause streak calculations to be wrong.
Once we send the prompt through, we can see that Amp shows it is consulting the Oracle:
Oracle analysis: Identifying the root cause
The Oracle then returns with its analysis and lets us know what the issues are:
With this feedback, it’s time for Amp to get to work on fixing the issue.
Using Amp to implement the fix
Now let's ask Amp to fix the identified issues:
The Oracle identified flawed logic in a few areas of the application. Use the feedback from the Oracle to fix and test the logic to make sure it works as intended and no longer has race conditions present.
Amp then goes to work, implementing fixes for the various issues that the Oracle identified. You can see the fixes being made by checking out the updated todos:
And we can see that Amp is changing the code accordingly based on the Oracle’s feedback:
Then, Amp creates a test script to verify that its changes handle concurrent updates without race conditions.
And lastly, it gives us a final confirmation message of the fixes, including a detailed breakdown of the key fixes applied and test results:
With just a few steps, we’ve had the Oracle debug and diagnose the race condition that we inadvertently introduced into our code. Then, we used this feedback to get Amp to fix the issue and confirm it through a series of generated tests.
Oracle analysis for different bug types
The Oracle's systematic analysis approach works well for various bug categories:
- Concurrency issues: Race conditions, deadlocks, shared state problems
- Logic errors: Edge cases, incorrect condition handling, state machine bugs
- Memory problems: Leaks, inefficient cleanup, unbounded growth
- Integration bugs: API contract mismatches, timing-dependent failures
- Performance issues: Inefficient algorithms, resource contention
Best practices for bug analysis with Oracle
When it comes to using the Oracle for bug analysis, there are some best practices that can help you get the most out of it. These tips include:
Be specific about symptoms: Include error messages, reproduction steps, and timing information
Provide relevant context: Share related code, configuration, and environment details where the bug occurs
Focus on complex interactions: Use Oracle for bugs involving multiple components or timing dependencies
Ask for a systematic analysis: Request a step-by-step breakdown of potential failure modes
Follow up with implementation: Use Amp to implement Oracle's recommended fixes immediately
When to use Oracle for debugging
Although you can use the Oracle whenever you want, certain scenarios make more sense than others. For example, ideal scenarios for invoking the Oracle include:
- Intermittent bugs that are hard to reproduce
- Issues that only appear under load or specific conditions
- Complex multi-component failures
- Race conditions and timing-related problems
On the other hand, bugs that include:
- Simple syntax errors or obvious logic mistakes
- Issues with clear stack traces pointing to specific lines
- Problems that are easily reproduced and debugged locally
These are less ideal for the Oracle and can likely be handled manually or through Amp’s main agent.
By using the Oracle in Amp, you can transform mysterious, intermittent bugs into well-understood problems with clear solutions. Using this tool for complex bugs can transform hours of trial-and-error debugging into an efficient process that requires only a few minutes.
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