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:

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