memory-watch/examples/basic-usage.js

Advanced Node.js memory monitoring with stack trace analysis, user code detection, and memory leak identification

const { MemoryWatch } = require("../dist/index");

// Example usage of MemoryWatch
const watch = new MemoryWatch({
  threshold: 0.8, // 80% of max heap
  interval: 30000, // Check every 30 seconds
  continuous: true, // Continue monitoring after reaching threshold
  actions: [
    (data) => {
      // Example 1: Simple logging
      console.log("🚨 Memory threshold reached!");
      console.log(`Usage: ${(data.percentage * 100).toFixed(2)}%`);
      console.log(`Amount: ${data.usedBytes} / ${data.totalBytes} bytes`);
      console.log(`Time: ${data.timestamp}`);
      console.log(`Trigger source: ${data.context?.triggerSource}`);
      console.log("---");
    },

    async (data) => {
      // Example 2: Send Slack notification (you need to implement this)
      console.log("Sending Slack notification:", {
        message: `Memory usage reached ${(data.percentage * 100).toFixed(2)}%`,
        timestamp: data.timestamp,
        process: data.context?.pid,
        platform: data.context?.platform,
      });

      // Here you can write the actual Slack sending code
      // await sendSlackNotification(data);
    },

    (data) => {
      // Example 3: Save to log file
      const logMessage = `[${data.timestamp.toISOString()}] Memory Alert: ${(
        data.percentage * 100
      ).toFixed(2)}% used (${data.usedBytes}/${
        data.totalBytes
      } bytes) - Trigger: ${data.context?.triggerSource}\n`;

      // Here you can write the file writing code
      console.log("Log message to save:", logMessage);
      // require('fs').appendFileSync('./memory-alerts.log', logMessage);
    },
  ],
});

// Start monitoring
watch.start();

console.log("Memory monitoring started...");
console.log("Press Ctrl+C to stop");

// Example usage of static method for one-time check
MemoryWatch.checkOnce(0.5).then((result) => {
  if (result) {
    console.log("Memory usage is above 50%:", result);
  } else {
    console.log("Memory usage is below 50%");
  }
});

// Sample function to create memory pressure (for testing)
function createMemoryPressure() {
  const arrays = [];
  for (let i = 0; i < 1000; i++) {
    arrays.push(new Array(10000).fill(Math.random()));
  }
  return arrays;
}

// Test memory pressure after 5 seconds
setTimeout(() => {
  console.log("Creating memory pressure for testing...");
  createMemoryPressure();
}, 5000);

// Stop after 2 minutes
setTimeout(() => {
  watch.stop();
  console.log("Memory monitoring stopped");
  process.exit(0);
}, 120000);