File System

1import { readFile, writeFile, readdir, stat } from "fs/promises";
2import { join } from "path";
3 
4// Read a file with proper typing
5async function readTextFile(path: string): Promise<string> {
6  const content = await readFile(path, "utf-8");
7  return content;
8}
9 
10// Write a file
11async function writeTextFile(path: string, content: string): Promise<void> {
12  await writeFile(path, content, "utf-8");
13  console.log(`Written to ${path}`);
14}
15 
16// Read JSON file with type parameter
17async function readJsonFile<T>(path: string): Promise<T> {
18  const content = await readFile(path, "utf-8");
19  return JSON.parse(content) as T;
20}
21 
22// Write JSON file
23async function writeJsonFile<T>(path: string, data: T): Promise<void> {
24  const content = JSON.stringify(data, null, 2);
25  await writeFile(path, content, "utf-8");
26}
27 
28// List directory contents
29interface FileInfo {
30  name: string;
31  isDirectory: boolean;
32  size: number;
33}
34 
35async function listDirectory(dirPath: string): Promise<FileInfo[]> {
36  const entries = await readdir(dirPath);
37 
38  const fileInfos = await Promise.all(
39    entries.map(async (name) => {
40      const fullPath = join(dirPath, name);
41      const stats = await stat(fullPath);
42 
43      return {
44        name,
45        isDirectory: stats.isDirectory(),
46        size: stats.size,
47      };
48    })
49  );
50 
51  return fileInfos;
52}
53 
54// Example usage
55async function main(): Promise<void> {
56  // Read package.json
57  interface PackageJson {
58    name: string;
59    version: string;
60    dependencies?: Record<string, string>;
61  }
62 
63  const pkg = await readJsonFile<PackageJson>("./package.json");
64  console.log(`Package: ${pkg.name} v${pkg.version}`);
65 
66  // List current directory
67  const files = await listDirectory(".");
68  files.forEach((f) => {
69    const type = f.isDirectory ? "[DIR]" : "[FILE]";
70    console.log(`${type} ${f.name} (${f.size} bytes)`);
71  });
72}
73 
74main().catch(console.error);