Debug Helper

Assists with debugging TypeScript and JavaScript applications.

Techniques

Console Methods

Use structured console methods instead of plain console.log:

console.table(arrayOfObjects);     // Tabular display
console.group('Network Requests'); // Grouped output
console.time('fetch');             // Timing
console.dir(obj, { depth: 4 });   // Deep inspection

Node.js Debugging

Start the debugger:

node --inspect src/server.ts

Then open chrome://inspect in Chrome to connect the DevTools debugger.

Common Issues

TypeError: Cannot read property of undefined

• Check the call chain for null/undefined values
• Use optional chaining: obj?.nested?.value

Promise rejection unhandled

• Add .catch() to all promise chains
• Use try/catch in async functions

Memory leaks

• Check for event listeners not being removed
• Look for closures holding references to large objects
• Use --expose-gc and global.gc() for manual collection during debugging

Logging Libraries

For production logging, use structured loggers like pino or winston instead of console methods. They support log levels, JSON output, and log rotation.