Feat node basics

src/cli/args.js

@@ -1,5 +1,16 @@
 const parseArgs = () => {
     // Write your code here 
+
+    const args = process.argv.slice(2);
+    const result = [];
+    args.forEach((arg, index) => {
+        if(arg.startsWith('--')) {
+            // console.log(`${arg.slice(2)}: ${args[index + 1]}`);
+            result.push(`${arg.slice(2)}: ${args[index + 1]}`);
+        }
+    });
+
+    console.log(result.join(', '));
 };
 
 parseArgs();

src/cli/env.js

@@ -1,5 +1,12 @@
 const parseEnv = () => {
     // Write your code here 
+    // console.log(process.env);
+
+    for(const key in process.env) {
+        if (key.startsWith('RSS_')) {
+            console.log(`${key}=${process.env[key]};`);
+        }
+    }
 };
 
 parseEnv();

src/fs/copy.js

@@ -1,5 +1,16 @@
+import fs from 'fs/promises';
+import path from 'path';
+import url from 'url';
+
+
+
 const copy = async () => {
     // Write your code here 
+    const __filename = url.fileURLToPath(import.meta.url);
+    const __dirname = path.dirname(__filename);
+    const srcPath = path.join(__dirname, 'files');
+    const destPath = path.join(__dirname, 'files_copy');
+
 };
 
 await copy();

src/fs/create.js

@@ -1,5 +1,27 @@
+import fs from 'fs/promises';
+import path from 'path';
+import url from 'url';
+
+
+
 const create = async () => {
-    // Write your code here 
+    // Write your code here
+    const __filename = url.fileURLToPath(import.meta.url);
+    const __dirname = path.dirname(__filename);
+    const file = path.join(__dirname, 'files', 'fresh.txt');;
+    const dataToWrite = 'I am fresh and young';
+
+    try {
+        await fs.access(file);
+
+        throw new Error('FS operation failed');
+    } catch (error) {
+        if (error.code === 'ENOENT') {
+            await fs.writeFile(file, dataToWrite);
+        } else {
+            throw error;
+        }
+    }
 };
 
 await create();

src/fs/files/fresh.txt

@@ -0,0 +1 @@
+I am fresh and young

src/hash/calcHash.js

@@ -1,5 +1,24 @@
+import { createHash } from 'crypto';
+import fs from 'fs';
+import path from 'path';
+import url from 'url';
+
 const calculateHash = async () => {
     // Write your code here 
+    const __filename = url.fileURLToPath(import.meta.url);
+    const file = path.join(path.dirname(__filename), 'files', 'fileToCalculateHashFor.txt');
+    const fileReadStream = fs.createReadStream(file);
+
+    const hash = createHash('sha256');
+
+    fileReadStream.on('data', (data) => {
+        hash.update(data);
+    });
+
+    fileReadStream.on('end', () => {
+        const fileHash = hash.digest('hex');
+        console.log(fileHash);
+    });
 };
 
 await calculateHash();

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

@@ -1,24 +1,24 @@
-const path = require('path');
-const { release, version } = require('os');
-const { createServer: createServerHttp } = require('http');
-require('./files/c');
+import path from 'path';
+import { release, version } from 'os';
+import { createServer as createServerHttp } from 'http';
+import './files/c.js';
 
 const random = Math.random();
 
 let unknownObject;
 
 if (random > 0.5) {
-    unknownObject = require('./files/a.json');
+    unknownObject = await import('./files/a.json', { assert: { type: 'json' } });
 } else {
-    unknownObject = require('./files/b.json');
+    unknownObject = await import('./files/b.json', { assert: { type: 'json' } });
 }
 
 console.log(`Release ${release()}`);
 console.log(`Version ${version()}`);
 console.log(`Path segment separator is "${path.sep}"`);
 
-console.log(`Path to current file is ${__filename}`);
-console.log(`Path to current directory is ${__dirname}`);
+console.log(`Path to current file is ${import.meta.url}`);
+console.log(`Path to current directory is ${import.meta.url}`);
 
 const myServer = createServerHttp((_, res) => {
     res.end('Request accepted');
@@ -33,7 +33,7 @@ myServer.listen(PORT, () => {
     console.log('To terminate it, use Ctrl+C combination');
 });
 
-module.exports = {
+export {
     unknownObject,
     myServer,
 };

src/streams/files/fileToWrite.txt

@@ -0,0 +1 @@
+Hello, STREAM!

src/streams/read.js

@@ -1,5 +1,19 @@
+import fs from 'fs';
+import path from 'path';
+import url from 'url';
+
 const read = async () => {
     // Write your code here 
+    // console.log(process.cwd());
+    const __filename = url.fileURLToPath(import.meta.url);
+    const file = path.join(path.dirname(__filename), 'files', 'fileToRead.txt');
+
+    const readStream = fs.createReadStream(file, 'utf-8');
+    readStream.pipe(process.stdout);
+
+    readStream.on('error', (error) => {
+        console.error('Error while reading file:', error);
+    });
 };
 
 await read();

src/streams/transform.js

@@ -1,5 +1,18 @@
+import fs from 'fs';
+import { Transform } from 'stream';
+
 const transform = async () => {
     // Write your code here 
+    const transformStream = new Transform({
+        transform(chunk, encoding, callback) {
+            const transformedChunk = chunk.toString().split('').reverse().join('');
+            callback(null, transformedChunk);
+        }
+    });
+
+    process.stdin
+        .pipe(transformStream)
+        .pipe(process.stdout);
 };
 
 await transform();

src/streams/write.js

@@ -1,5 +1,26 @@
+import fs from 'fs';
+import path from 'path';
+import url from 'url';
+
 const write = async () => {
     // Write your code here 
+    const __filename = url.fileURLToPath(import.meta.url);
+    const file = path.join(path.dirname(__filename), 'files', 'fileToWrite.txt');
+
+    const writeStream = fs.createWriteStream(file);
+
+    process.stdin.once('data', (userInput) => {
+        writeStream.write(userInput, () => {
+            console.log('Your input was succesfully written');
+
+            writeStream.end();
+            process.exit();
+        });
+    });
+
+    writeStream.on('error', (error) => {
+        console.error('Error while writing to file:', error);
+    });
 };
 
 await write();

src/zip/compress.js

@@ -1,5 +1,29 @@
+import fs from 'fs';
+import path from 'path';
+import url from 'url';
+import zlib from 'zlib';
+
 const compress = async () => {
     // Write your code here 
+    const __filename = url.fileURLToPath(import.meta.url);
+    const file = path.join(path.dirname(__filename), 'files', 'fileToCompress.txt');
+    const output = path.join(path.dirname(__filename), 'files', 'archive.gz');
+
+    const gzip = zlib.createGzip();
+    const readStream = fs.createReadStream(file);
+    const writeStream = fs.createWriteStream(output);
+
+    writeStream.on('finish', () => {
+        console.log('Compressed.');
+    });
+    readStream.on('error', (err) => {
+        console.error('Error while reading file:', err);
+    });
+    writeStream.on('error', (err) => {
+        console.error('Error while writing compressed file:', err);
+    });
+
+    readStream.pipe(gzip).pipe(writeStream);
 };
 
 await compress();

src/zip/decompress.js

@@ -1,5 +1,29 @@
+import fs from 'fs';
+import path from 'path';
+import url from 'url';
+import zlib from 'zlib';
+
 const decompress = async () => {
     // Write your code here 
+    const __filename = url.fileURLToPath(import.meta.url);
+    const file = path.join(path.dirname(__filename), 'files', 'archive.gz');
+    const output = path.join(path.dirname(__filename), 'files', 'fileToCompress.txt');
+
+    const gzip = zlib.createGunzip();
+    const readStream = fs.createReadStream(file);
+    const writeStream = fs.createWriteStream(output);
+
+    writeStream.on('finish', () => {
+        console.log('Decompressed.');
+    });
+    readStream.on('error', (err) => {
+        console.error('Error while reading file:', err);
+    });
+    writeStream.on('error', (err) => {
+        console.error('Error while writing decompressed file:', err);
+    });
+
+    readStream.pipe(gzip).pipe(writeStream);
 };
 
 await decompress();