What methods can be used to detect and fix memory leaks in an application?

To identify and fix memory leaks in a Node.js application, the following methods can be used:

1. Memory profiling using the built-in V8 profiler or tools like Chrome DevTools (via node --inspect). This allows taking heap snapshots and comparing them to find objects that are not released.

2. Using the heapdump module, which enables creating memory dumps at specific moments for later analysis.

3. Monitoring memory usage with process.memoryUsage() and logging to detect abnormal growth.

4. Leak detection tools, such as memwatch-next or leakage, which help identify leaks at runtime.

5. Analyzing code for reference retention: cycles, global variables, closures, caching without cleanup.

Example of running Node.js with an inspector for profiling:

node --inspect app.js

Then connect via Chrome DevTools, take a heap snapshot, and analyze objects that are not released after operations.