init: start task-1-nodejs-basics

src/cli/args.js

@@ -1,5 +1,14 @@
 const parseArgs = () => {
-  // Write your code here
+  const args = process.argv.slice(2); 
+
+  const result = [];
+  for (let i = 0; i < args.length; i += 2) {
+    const key = args[i].replace(/^--/, ''); 
+    const value = args[i + 1];
+    parts.push(`${key} is ${value}`);
+  }
+
+  console.log(result.join(', '));
 };
 
 parseArgs();

src/cli/env.js

@@ -1,5 +1,11 @@
 const parseEnv = () => {
-  // Write your code here
+
+  const envVariables = Object.entries(process.env)
+    .filter(([key]) => key.startsWith('RSS_'))
+    .map(([key, value]) => `${key}=${value}`)
+    .join('; ');
+
+    console.log(envVariables);
 };
 
 parseEnv();

src/cp/cp.js

@@ -1,6 +1,26 @@
-const spawnChildProcess = async (args) => {
-  // Write your code here
+import { spawn } from 'node:child_process';
+import { fileURLToPath } from 'node:url';
+
+export const spawnChildProcess = async (args = []) => {
+  const scriptPath = fileURLToPath(new URL('./files/script.js', import.meta.url));
+
+  const child = spawn(process.execPath, [scriptPath, ...args], {
+    stdio: ['pipe', 'pipe', 'inherit'], 
+  });
+
+  process.stdin.pipe(child.stdin);
+  child.stdout.pipe(process.stdout);
+
+  return new Promise((resolve, reject) => {
+    child.once('error', reject);
+    child.once('exit', (code) => {
+      process.stdin.unpipe(child.stdin);
+      child.stdout.unpipe(process.stdout);
+      if (code === 0) resolve();
+      else reject(new Error(`Child exited with code ${code}`));
+    });
+  });
 };
 
 // Put your arguments in function call to test this functionality
-spawnChildProcess( /* [someArgument1, someArgument2, ...] */);
+spawnChildProcess(  ["rs", "2025", "node.js"] );

src/fs/copy.js

@@ -1,5 +1,14 @@
+import fs from 'fs/promises';
+
 const copy = async () => {
-  // Write your code here
+  const source = new URL('./files/', import.meta.url);
+  const destination = new URL('./files_copy/', import.meta.url);
+
+  try {
+    await fs.cp(source, destination, { recursive: true, force: false, errorOnExist: true });
+  } catch {
+    throw new Error('FS operation failed');
+  }
 };
 
 await copy();

src/fs/create.js

@@ -1,5 +1,13 @@
+import fs from 'fs/promises';
+
 const create = async () => {
-  // Write your code here
+  const filePath = new URL('./fresh.txt', import.meta.url)
+
+  try {
+    await fs.writeFile(filePath, 'I am fresh and young', { flag: 'wx'})
+  } catch {
+    throw new Error('FS operation failed');
+  }
 };
 
 await create();

src/fs/delete.js

@@ -1,5 +1,13 @@
+import fs from 'fs/promises';
+
 const remove = async () => {
-  // Write your code here
+  const fileToRemove = new URL('./files/fileToRemove.txt', import.meta.url);
+
+  try {
+    await fs.unlink(fileToRemove);
+  } catch {
+    throw new Error('FS operation failed'); 
+  }
 };
 
 await remove();

src/fs/list.js

@@ -1,5 +1,14 @@
+import fs from 'fs/promises';
+
 const list = async () => {
-  // Write your code here
+  const folderToList = new URL('./files/', import.meta.url);
+
+  try {
+    const files = await fs.readdir(folderToList); 
+    console.log(files);
+  } catch {
+    throw new Error('FS operation failed');
+  }
 };
 
 await list();

src/fs/read.js

@@ -1,5 +1,14 @@
+import fs from 'fs/promises';
+
 const read = async () => {
-  // Write your code here
+   const fileToRead = new URL('./files/fileToRead.txt', import.meta.url);
+
+  try {
+    const contentToRead = await fs.readFile(fileToRead, 'utf-8');
+    console.log(contentToRead);
+  } catch {
+    throw new Error('FS operation failed');
+  }
 };
 
 await read();

src/fs/rename.js

@@ -1,5 +1,21 @@
+import fs from 'fs/promises';
+
 const rename = async () => {
-  // Write your code here
+  const source = new URL('./files/wrongFilename.txt', import.meta.url);
+  const destination = new URL('./files/properFilename.md', import.meta.url);
+
+  try {
+    try {
+      await fs.stat(destination);
+      throw new Error('FS operation failled');
+    } catch (e){
+      if (!e || e.code !== 'ENOENT')
+      throw new Error('FS operation failled');
+    }
+    await fs.rename(source, destination);
+  } catch {
+    throw new Error('FS operation failed');
+  }
 };
 
 await rename();

src/hash/calcHash.js

@@ -1,5 +1,20 @@
-const calculateHash = async () => {
-  // Write your code here
+import { createReadStream } from 'node:fs';
+import { createHash } from 'node:crypto';
+import { pipeline } from 'node:stream/promises';
+
+const calcHash = async () => {
+  const filePath = new URL('./files/fileToCalculateHashFor.txt', import.meta.url);
+
+  const hash = createHash('sha256'); 
+
+  try {
+    await pipeline(createReadStream(filePath), hash);
+
+    console.log(hash.digest('hex'));
+  } catch {
+    throw new Error('FS operation failed');
+  }
 };
 
-await calculateHash();
+await calcHash();
+

src/modules/cjsToEsm.cjs → src/modules/esm.mjs

@@ -1,12 +1,17 @@
-const path = require('node:path');
-const { release, version } = require('node:os');
-const { createServer: createServerHttp } = require('node:http');
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { release, version } from 'node:os';
+import { createServer as createServerHttp } from 'node:http';
 
-require('./files/c.cjs');
+import './files/c.cjs';
 
-const random = Math.random();
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
 
-const unknownObject = random > 0.5 ? require('./files/a.json') : require('./files/b.json');
+const random = Math.random();
+const unknownObject = random > 0.5
+  ? (await import('./files/a.json', { with: { type: 'json' } })).default
+  : (await import('./files/b.json', { with: { type: 'json' } })).default;
 
 console.log(`Release ${release()}`);
 console.log(`Version ${version()}`);
@@ -28,7 +33,4 @@ myServer.listen(PORT, () => {
   console.log('To terminate it, use Ctrl+C combination');
 });
 
-module.exports = {
-  unknownObject,
-  myServer,
-};
+export { unknownObject, myServer };

src/streams/files/fileToWrite.txt

@@ -0,0 +1 @@
+

src/streams/read.js

@@ -1,5 +1,16 @@
+import fs from 'node:fs';
+
 const read = async () => {
-  // Write your code here
+  const filePath = new URL('./files/fileToRead.txt', import.meta.url);
+
+  const readStream = fs.createReadStream(filePath, { encoding: 'utf-8' });
+
+  readStream.pipe(process.stdout);
+
+  readStream.on('error', () => {
+    throw new Error('FS operation failed');
+  });
 };
 
 await read();
+

src/streams/transform.js

@@ -1,5 +1,22 @@
+import { Transform } from 'node:stream';
+import { pipeline } from 'node:stream/promises';
+import { Readable } from 'node:stream';
+
 const transform = async () => {
-  // Write your code here
+  const mockData = process.stdin ? Readable.from('Hello world\n') : process.stdin;
+
+  const reverseTransform = new Transform({
+  transform(chunk, _enc, cb) {
+    const reversed = chunk.toString('utf8').split('').reverse().join('');
+    cb(null, reversed);
+  }
+});
+
+try {
+    await pipeline(mockData, reverseTransform, process.stdout);
+  } catch {
+    console.error('Stream operation failed');
+  }
 };
 
 await transform();

src/streams/write.js

@@ -1,5 +1,18 @@
+import fs from 'node:fs';
+import { pipeline } from 'node:stream/promises';
+import { Readable } from 'node:stream';
+
 const write = async () => {
-  // Write your code here
+  const filePath = new URL('./files/fileToWrite.txt', import.meta.url);
+  const writeStream = fs.createWriteStream(filePath, { encoding: 'utf-8' });
+   const mockData = process.stdin ? Readable.from('Hello world\n') : process.stdin;
+
+
+  try {
+    await pipeline(mockData, writeStream);
+  } catch {
+    throw new Error('FS operation failed');
+  }
 };
 
 await write();

src/wt/main.js

@@ -1,5 +1,39 @@
+import { cpus } from 'node:os';
+import { Worker } from 'node:worker_threads';
+
 const performCalculations = async () => {
-  // Write your code here
+
+  const runWorker = (n) =>
+    new Promise((resolve) => {
+      const worker = new Worker(new URL('./worker.js', import.meta.url), {
+        workerData: n, type: 'module'
+      });
+
+      worker.once('message', (value) => {
+        resolve({ status: 'resolved', data: value });
+      });
+
+      worker.once('error', (err) => {
+        console.error('worker error:', err)
+        resolve({ status: 'error', data: null });
+      });
+
+      worker.once('exit', (code) => {
+        if (code !== 0) {
+          resolve({ status: 'error', data: null });
+        }
+      });
+  });
+
+  const coreCount = cpus().length;
+  const start = 10;
+
+  const workerPromises = Array.from({ length: coreCount }, (_, i) =>
+    runWorker(start + i)
+  );
+
+  const results = await Promise.all(workerPromises);
+  console.log(results);
 };
 
 await performCalculations();

src/wt/worker.js

@@ -1,8 +1,17 @@
+import { parentPort, workerData } from 'node:worker_threads';
+
 // n should be received from main thread
 const nthFibonacci = (n) => n < 2 ? n : nthFibonacci(n - 1) + nthFibonacci(n - 2);
 
-const sendResult = () => {
+const sendResult = (n) => {
   // This function sends result of nthFibonacci computations to main thread
+  const result = nthFibonacci(Number(n));
+  parentPort.postMessage(result);  
 };
 
-sendResult();
+if (workerData !== undefined) {
+  sendResult(workerData);
+} else {
+  parentPort.once('message', sendResult);
+}
+

src/zip/compress.js

@@ -1,5 +1,21 @@
+import fs from 'node:fs';
+import { pipeline } from 'node:stream/promises';
+import { createGzip } from 'node:zlib';
+
 const compress = async () => {
-  // Write your code here
+  const source = new URL('./files/fileToCompress.txt', import.meta.url);
+  const destination = new URL('./files/archive.gz', import.meta.url);
+
+  try {
+    await pipeline(
+      fs.createReadStream(source),
+      createGzip(),                  
+      fs.createWriteStream(destination)
+    );
+  } catch {
+
+    throw new Error('FS operation failed');
+  }
 };
 
 await compress();