Debugging Node.js

Debugging starts with reproducing the problem and reading the complete error message and stack trace.

• Use logs for important application state.
• Use the Node inspector with a supported IDE.
• Reduce complex failures to smaller test cases.
• Never log passwords or tokens.

Deep dive

Read stack traces from the bottom up carefully

A stack trace shows where an error occurred and how execution reached that point. Focus on the first application-level location you control, then inspect the values and assumptions around it.