a0.dev

Bug Fix & Debugging

4 snippets

Fix “undefined is not a function” Error

A typical JS bug when a method or callback isn’t properly defined.

I’m getting “undefined is not a function” when calling this method: [Paste code and error] Why is this happening, and how can I fix it?

Identify Root Cause from Error Trace

Use this prompt when you encounter an unfamiliar error message or crash in your app.

Here’s the error trace from my console: [Paste error trace or stack trace] Based on this output, what is the most likely root cause and which file or function should I inspect first?

Fix a Non-Working Button

A button appears in the UI but doesn’t trigger any action.

This button renders but doesn’t respond to clicks. Here’s the component code: [Paste button component] Can you help debug why the `onClick` isn't firing or working properly?

Resolve State Not Updating Issue

State seems to update but UI does not reflect the change.

The UI doesn’t update when I change the state. Here’s my component: [Paste relevant code] Can you find out why the state change isn’t reflected in the rendered output?