This chapter presents you with a challenge: creating an advanced console app named DirInspect Pro. This app will empower you to thoroughly analyze any directory and gain insightful statistics about its files and subdirectories.

🏆 Challenge Awaits

Picture a scenario where you must navigate a labyrinth of folders containing crucial files and data. DirInspect Pro is your ally in this journey, providing comprehensive insights into the directory's structure and contents.

🚀 The Resulting App

Get ready to wield DirInspect Pro's capabilities. The app will furnish you with critical information, such as

• The total number of items;
• The aggregate size of all items;
• The largest file's name and size;
• The detailed list of individual file names and sizes.

Two Paths to Choose

You have two paths ahead.

• The first is to tackle this challenge head-on, honing your skills without guidance;
• The second is to follow a helpful guide that guarantees your success.

Whichever path you choose, you're in for a rewarding journey culminating in creating a captivating and functional console app.

Masterplan

• 👉 Step 1: Import Required Modules;
• 👉 Step 2: Define getStats Function;
• 👉 Step 3: Define analyzeFile Function;
• 👉 Step 4: Define analyzeDirectory Function;
• 👉 Step 5: Define main Function and Invoke;
• 🎉 Conclusion;
• 🏁 Full App Code.

Step 1: Import Required Modules

To embark on this adventure, you'll need the right tools. Begin by importing two key modules: fs.promises to manage the file system asynchronously and path to handle file paths effectively.

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const fs = require("fs").promises;
const path = require("path");

Step 2: Define getStats Function

The asynchronous function, getStats, takes a file or directory path as an argument and attempts to retrieve its statistics using fs.stat.

• If successful, it returns the statistics;
• If an error occurs, it logs an error message and returns null.

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async function getStats(filePath) {
  try {
    const stats = await fs.stat(filePath);
    return stats;
  } catch (err) {
    console.error("Error getting stats:", err.message);
    return null;
  }
}

Step 3: Define analyzeFile Function

The analyzeFile function uses the getStats function to obtain statistics for a file. If statistics are available (not null), it returns an object containing the file's name (extracted using path.basename) and its size.

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async function analyzeFile(filePath) {
  const stats = await getStats(filePath);
  if (!stats) return null;

  return {
    name: path.basename(filePath),
    size: stats.size,
  };
}

Step 4: Define analyzeDirectory Function

The analyzeDirectory function takes a directory path as an argument and comprehensively analyzes its contents.

• It begins by reading the items within the directory using fs.readdir and then iterates through each item;
• For each item, it constructs the full path using path.join and retrieves its statistics using the getStats function;
• If the stats indicate that the item is a file, it updates file-related statistics;
• If the item is a subdirectory, it recursively calls the analyzeDirectory function to analyze its contents and then aggregates the statistics.

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async function analyzeDirectory(directoryPath) {
  try {
    const items = await fs.readdir(directoryPath);
    let totalItems = 0;
    let totalFiles = 0;
    let totalSize = 0;
    let largestFile = { name: "", size: 0 };
    let fileList = [];

    for (const item of items) {
      const itemPath = path.join(directoryPath, item);
      const stats = await getStats(itemPath);
      if (!stats) continue;

      totalItems++;

      if (stats.isFile()) {
        totalFiles++;
        totalSize += stats.size;

        if (stats.size > largestFile.size) {
          largestFile = { name: item, size: stats.size };
        }

        fileList.push({ name: item, size: stats.size });
      } else if (stats.isDirectory()) {
        const subDirectoryStats = await analyzeDirectory(itemPath);
        totalItems += subDirectoryStats.totalItems;
        totalFiles += subDirectoryStats.totalFiles;
        totalSize += subDirectoryStats.totalSize;

        if (subDirectoryStats.largestFile.size > largestFile.size) {
          largestFile = subDirectoryStats.largestFile;
        }

        fileList = fileList.concat(subDirectoryStats.fileList);

Step 5: Define main Function and Invoke

The main function is the entry point of the script. It specifies the directory path to analyze (in this case, ./docs), calls the analyzeDirectory function to obtain the statistics of the directory and its contents, and then outputs the collected information. The function prints out

• The total number of items;
• The total number of files;
• The total size;
• The details about the largest file;
• The list of files in the directory.

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async function main() {
  const directoryPath = "./docs";
  const directoryStats = await analyzeDirectory(directoryPath);

  console.log("Directory Analysis:");
  console.log("Total items:", directoryStats.totalItems);
  console.log("Total files:", directoryStats.totalFiles);
  console.log("Total size (bytes):", directoryStats.totalSize);
  console.log(
    "Largest file:",
    directoryStats.largestFile.name,
    "Size:",
    directoryStats.largestFile.size,
    "bytes"
  );

  console.log("\nFile List:");
  for (const file of directoryStats.fileList) {
    console.log(file.name, "Size:", file.size, "bytes");
  }
}

main();

🎉 Conclusion: Mastered Skills

With DirInspect Pro, you've mastered the art of analyzing directories like a pro. This console app showcases your ability to extract file statistics, handle errors seamlessly, and unveil meaningful insights about files and subdirectories within a specified directory.

👨‍💻 Full App Code

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const fs = require("fs").promises;
const path = require("path");

async function getStats(filePath) {
  try {
    const stats = await fs.stat(filePath);
    return stats;
  } catch (err) {
    console.error("Error getting stats:", err.message);
    return null;
  }
}

async function analyzeFile(filePath) {
  const stats = await getStats(filePath);
  if (!stats) return null;

  return {
    name: path.basename(filePath),
    size: stats.size,
  };
}

async function analyzeDirectory(directoryPath) {
  try {
    const items = await fs.readdir(directoryPath);

    let totalItems = 0;
    let totalFiles = 0;
    let totalSize = 0;
    let largestFile = { name: "", size: 0 };
    let fileList = [];

    for (const item of items) {
      const itemPath = path.join(directoryPath, item);
      const stats = await getStats(itemPath);