npm-install-size/lib/analyze.js

Check the install size of any NPM package before installing it.

import fs from 'fs/promises';
import path from 'path';

export async function getDirStats(dir) {
  let total = 0;
  let count = 0;
  let largest = { name: null, size: 0 };
  async function walk(current) {
    const entries = await fs.readdir(current, { withFileTypes: true });
    for (const entry of entries) {
      const fullPath = path.join(current, entry.name);
      if (entry.isDirectory()) {
        await walk(fullPath);
      } else if (entry.isFile()) {
        const stat = await fs.stat(fullPath);
        total += stat.size;
        count++;
        if (stat.size > largest.size) {
          largest = { name: path.relative(dir, fullPath), size: stat.size };
        }
      }
    }
  }
  await walk(dir);
  return { total, count, largest };
}

export async function getAllFilesWithSizes(dir) {
  const files = [];
  async function walk(current) {
    const entries = await fs.readdir(current, { withFileTypes: true });
    for (const entry of entries) {
      const fullPath = path.join(current, entry.name);
      if (entry.isDirectory()) {
        await walk(fullPath);
      } else if (entry.isFile()) {
        const stat = await fs.stat(fullPath);
        files.push({ path: path.relative(dir, fullPath), size: stat.size });
      }
    }
  }
  await walk(dir);
  return files;
}

export function getFileTypeBreakdown(files) {
  const breakdown = {};
  for (const f of files) {
    const ext = path.extname(f.path) || 'NOEXT';
    breakdown[ext] = (breakdown[ext] || 0) + f.size;
  }
  return breakdown;
}

export function estimateDownloadTime(bytes, mbps = 10) {
  // mbps: megabits per second
  const bits = bytes * 8;
  const seconds = bits / (mbps * 1_000_000);
  if (seconds < 1) return '<1s';
  if (seconds < 60) return `${Math.round(seconds)}s`;
  return `${Math.floor(seconds / 60)}m ${Math.round(seconds % 60)}s`;
}

export async function cleanup(dir) {
  try {
    await fs.rm(dir, { recursive: true, force: true });
  } catch {}
}

export async function findMainJsFile(dir) {
  // Try to find main entry from package.json, fallback to index.js
  try {
    const pkgJsonPath = path.join(dir, 'package.json');
    const pkgJson = JSON.parse(await fs.readFile(pkgJsonPath, 'utf8'));
    let main = pkgJson.module || pkgJson.main;
    if (main) {
      const mainPath = path.join(dir, main);
      try {
        await fs.access(mainPath);
        return mainPath;
      } catch {}
    }
  } catch {}
  // Fallback to index.js
  const fallback = path.join(dir, 'index.js');
  try {
    await fs.access(fallback);
    return fallback;
  } catch {}
  // Otherwise, try to find any .js file
  const files = await fs.readdir(dir);
  for (const file of files) {
    if (file.endsWith('.js')) return path.join(dir, file);
  }
  return null;
}