/memory-leak-detection

name: memory-leak-detection
description: >
  Detect and fix memory leaks using heap snapshots, memory profiling, and leak
  detection tools. Use when investigating memory growth, OOM errors, or
  optimizing memory usage.

Memory Leak Detection

Table of Contents

• [Overview](#overview)
• [When to Use](#when-to-use)
• [Quick Start](#quick-start)
• [Reference Guides](#reference-guides)
• [Best Practices](#best-practices)

Overview

Identify and fix memory leaks to prevent out-of-memory crashes and optimize application performance.

When to Use

• Memory usage growing over time
• Out of memory (OOM) errors
• Performance degradation
• Container restarts
• High memory consumption

Quick Start

Minimal working example:

import v8 from "v8";
import fs from "fs";

class MemoryProfiler {
  takeSnapshot(filename: string): void {
    const snapshot = v8.writeHeapSnapshot(filename);
    console.log(`Heap snapshot saved to ${snapshot}`);
  }

  getMemoryUsage(): NodeJS.MemoryUsage {
    return process.memoryUsage();
  }

  formatMemory(bytes: number): string {
    return `${(bytes / 1024 / 1024).toFixed(2)} MB`;
  }

  printMemoryUsage(): void {
    const usage = this.getMemoryUsage();

    console.log("Memory Usage:");
    console.log(`  RSS: ${this.formatMemory(usage.rss)}`);
    console.log(`  Heap Total: ${this.formatMemory(usage.heapTotal)}`);
    console.log(`  Heap Used: ${this.formatMemory(usage.heapUsed)}`);
    console.log(`  External: ${this.formatMemory(usage.external)}`);
// ... (see reference guides for full implementation)

Reference Guides

Detailed implementations in the `references/` directory:

| Guide | Contents | |---|---| | [Node.js Heap Snapshots](references/nodejs-heap-snapshots.md) | Node.js Heap Snapshots | | [Memory Leak Detection Middleware](references/memory-leak-detection-middleware.md) | Memory Leak Detection Middleware | | [Common Memory Leak Patterns](references/common-memory-leak-patterns.md) | Common Memory Leak Patterns | | [Python Memory Profiling](references/python-memory-profiling.md) | Python Memory Profiling | | [WeakMap/WeakRef for Cache](references/weakmapweakref-for-cache.md) | WeakMap/WeakRef for Cache | | [Memory Monitoring in Production](references/memory-monitoring-in-production.md) | Memory Monitoring in Production |

Best Practices

✅ DO

• Remove event listeners when done
• Clear timers and intervals
• Use WeakMap/WeakRef for caches
• Limit cache sizes
• Monitor memory in production
• Profile regularly
• Clean up after tests

❌ DON'T

• Create circular references
• Hold references to large objects unnecessarily
• Forget to clean up resources
• Ignore memory growth
• Skip WeakMap for object caches