Traverse directories and show lines of code

show-lines-of-code.js

const fs = require('fs');
const path = require('path');

function walkDir(dir, callback) {
  fs.readdirSync(dir).forEach(file => {
    const dirPath = path.join(dir, file);
    const isDirectory = fs.statSync(dirPath).isDirectory();
    isDirectory ?
      walkDir(dirPath, callback) : callback(path.join(dir, file));
  });
}

function countLines(filePath) {
  return new Promise((resolve, reject) => {
    let count = 0;
    fs.createReadStream(filePath)
      .on('error', reject)
      .on('data', chunk => {
        for (let i = 0; i < chunk.length; ++i) if (chunk[i] === 10) count++;
      })
      .on('end', () => resolve(count));
  });
}

const dir = process.cwd();
console.log(`Walking through directory "${dir}".`);

walkDir(dir, async (filePath) => {
  if (filePath.endsWith('.js')) {
    const loc = await countLines(filePath);
    console.log(`- [ ] ${filePath.substr(dir.length + 1)} (${loc} lines)`);
  }
});