nodejs-basic

.gitignore

@@ -0,0 +1 @@
+.idea

Readme.md

@@ -1,3 +1,2 @@
 # Node.js basics
 
-## !!! Please don't submit Pull Requests to this repository !!!

package.json

@@ -4,7 +4,24 @@
   "description": "This repository is the part of nodejs-assignments https://github.com/AlreadyBored/nodejs-assignments",
   "type": "module",
   "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "echo \"Error: no test specified\" && exit 1",
+    "read": "node src/fs/read.js",
+    "copy": "node src/fs/copy.js",
+    "create": "node src/fs/create.js",
+    "list-files": "node src/fs/list.js",
+    "delete": "node src/fs/delete.js",
+    "rename": "node src/fs/rename.js",
+    "cp": "node src/cp/cp.js",
+    "args": "node src/cli/args.js --first-name Masha --last-name Marchenko",
+    "env": "npx cross-env RSS_first_name=Masha RSS_last_name=Marchenko birthyear=2001 node src/cli/env.js",
+    "calc-hash": "node src/hash/calcHash.js",
+    "modules": "node src/modules/cjsToEsm.mjs",
+    "read-stream": "node src/streams/read.js",
+    "transform-stream": "node src/streams/transform.js",
+    "write-stream": "node src/streams/write.js",
+    "wt": "node src/wt/main.js",
+    "compress": "node src/zip/compress.js",
+    "decompress": "node src/zip/decompress.js"
   },
   "repository": {
     "type": "git",

src/cli/args.js

@@ -1,3 +1,15 @@
 export const parseArgs = () => {
-    // Write your code here 
-};
+    const userInputArgs = process.argv.slice(2);
+    const cliArguments = userInputArgs.reduce((acc, arg, index, arr) => {
+        const value = arr[index + 1];
+        if (value && arg.startsWith('--')) {
+            const transformedArg = arg.slice(2);
+            const cliArgumentsTransformed = `${transformedArg} is ${value}`;
+            acc.push(cliArgumentsTransformed);
+        } return acc;
+    }, [])
+
+    console.log(cliArguments.join(', '));
+};
+
+parseArgs();

src/cli/env.js

@@ -1,3 +1,9 @@
 export const parseEnv = () => {
-    // Write your code here 
-};
+    const rssVariables = Object.entries(process.env)
+        .filter(([key, _]) => key.startsWith('RSS_'))
+        .map(([key, value]) => `${key}=${value}`)
+
+    console.log(rssVariables.join('; '))
+};
+
+parseEnv();

src/common.js

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+import { dirname } from "path";
+import { fileURLToPath } from "url";
+
+export function getDirname(url) {
+    const __filename = fileURLToPath(url);
+
+    return dirname(__filename);
+}

src/cp/cp.js

@@ -1,3 +1,15 @@
+import child_process from 'child_process';
+import path from "path";
+import {getDirname} from "../common.js";
+
 export const spawnChildProcess = async (args) => {
-    // Write your code here
-};
+    const __dirname = getDirname(import.meta.url);
+    const filePath = path.join(__dirname, 'files', 'script.js');
+
+    const child = child_process.fork(filePath, args)
+
+    process.stdin.pipe(child.stdin);
+    child.stdout.pipe(process.stdin);
+};
+
+spawnChildProcess('--silent --all')

src/fs/constants.js

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+export const DEFAULT_ERROR_MESSAGE = 'FS operation failed.';

src/fs/copy.js

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+import fs from 'fs/promises';
+import path from 'path';
+import {DEFAULT_ERROR_MESSAGE} from "./constants.js";
+import { getDirname } from '../common.js'
+
+
 export const copy = async () => {
-    // Write your code here 
-};
+    const __dirname = getDirname(import.meta.url);
+    const srcPath = path.join(__dirname, 'files');
+    const destPath = path.join(__dirname, 'files_copy');
+
+    try {
+        await fs.mkdir(destPath);
+        const srcFiles = await fs.readdir(srcPath);
+        await Promise.all(srcFiles.map(file => fs.copyFile(path.join(srcPath, file), path.join(destPath, file))))
+            .then(() => 'The files were copied to a new folder')
+    } catch {
+        throw new Error(DEFAULT_ERROR_MESSAGE);
+    }
+};
+
+copy();

src/fs/create.js

@@ -1,3 +1,17 @@
+import fs from 'fs/promises';
+import path from 'path';
+import { DEFAULT_ERROR_MESSAGE } from "./constants.js";
+import { getDirname } from "../common.js";
+
+
 export const create = async () => {
-    // Write your code here 
-};
+    const filePath = path.join(getDirname(import.meta.url), 'files', 'fresh.txt');
+    const content = 'I am fresh and young';
+    try {
+        await fs.writeFile(filePath, content, {flag: 'wx'}).then(() => console.log('"fresh.txt" was created'))
+    } catch {
+        throw new Error(DEFAULT_ERROR_MESSAGE)
+    }
+};
+
+create();

src/fs/delete.js

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+import path from "path";
+import fs from 'fs';
+import {DEFAULT_ERROR_MESSAGE} from "./constants.js";
+import {getDirname} from "../common.js";
+
 export const remove = async () => {
-    // Write your code here 
-};
+    const __dirname = getDirname(import.meta.url);
+    const filePath = path.join(__dirname, 'files', 'fileToRemove.txt');
+
+    fs.rm(filePath, (err) => {
+        if (err) {
+            throw new Error(DEFAULT_ERROR_MESSAGE);
+        } else {
+            console.log('The file was deleted');
+        }
+    })
+};
+
+remove();

src/fs/files/hello.txt

@@ -1 +1 @@
-Hello Node.js
+Hello node.js

src/fs/list.js

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+import path from "path";
+import fs from "fs";
+import {DEFAULT_ERROR_MESSAGE} from "./constants.js";
+import {getDirname} from "../common.js";
+
 export const list = async () => {
-    // Write your code here 
-};
+    const __dirname = getDirname(import.meta.url);
+    const filesPath = path.join(__dirname, 'files');
+
+    if (!fs.existsSync(filesPath)) {
+        throw new Error(DEFAULT_ERROR_MESSAGE);
+    }
+
+    fs.readdir(filesPath, (_, files) => {
+        console.log(files)
+    })
+}
+
+list();

src/fs/read.js

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+import path from "path";
+import fs from "fs";
+import {DEFAULT_ERROR_MESSAGE} from "./constants.js";
+import {getDirname} from "../common.js";
+
 export const read = async () => {
-    // Write your code here 
-};
+    const __dirname = getDirname(import.meta.url);
+    const filePath = path.join(__dirname, 'files', 'fileToRead.txt');
+
+    if (!fs.existsSync(filePath)) {
+        throw new Error(DEFAULT_ERROR_MESSAGE);
+    }
+
+    fs.readFile(filePath, 'utf8', (err, data) => console.log(data))
+};
+
+read();

src/fs/rename.js

@@ -1,3 +1,25 @@
+import path from "path";
+import fs from "fs";
+import {DEFAULT_ERROR_MESSAGE} from "./constants.js";
+import {getDirname} from "../common.js";
+
 export const rename = async () => {
-    // Write your code here 
-};
+    const __dirname = getDirname(import.meta.url);
+    const wrongNamedFilePath = path.join(__dirname, 'files', 'wrongFilename.txt');
+    const newFilePath = path.join(__dirname, 'files', 'properFilename.md')
+
+    if (!fs.existsSync(wrongNamedFilePath) || fs.existsSync(newFilePath)) {
+            throw new Error(DEFAULT_ERROR_MESSAGE);
+    }
+
+     fs.rename(wrongNamedFilePath, newFilePath, (err) => {
+        if (err) {
+            throw new Error(DEFAULT_ERROR_MESSAGE);
+        } else {
+            console.log('The file was renamed')
+        }
+    });
+};
+
+rename();
+

src/hash/calcHash.js

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+import crypto from 'crypto';
+import fs from 'fs';
+import path, {dirname} from "path";
+import {fileURLToPath} from "url";
+
 export const calculateHash = async () => {
-    // Write your code here 
-};
+    const __dirname = dirname(fileURLToPath(import.meta.url));
+    const filePath = path.join(__dirname, 'files', 'fileToCalculateHashFor.txt');
+    const readable = fs.createReadStream(filePath);
+    const hash = crypto.createHash('sha256');
+
+    return new Promise(resolve => {
+        readable.on('data', data => hash.update(data)).on('end', () => resolve(hash.digest('hex')))
+    })
+};
+
+console.log(await calculateHash());

src/modules/cjsToEsm.mjs

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+import { release, version } from 'os';
+import { createServer as createServerHttp } from 'http';
+import path from 'path';
+import { fileURLToPath } from 'url';
+import './files/c.js';
+import { getDirname } from "../common.js";
+
+const random = Math.random();
+const __dirname = getDirname(import.meta.url);
+const __filename = fileURLToPath(import.meta.url);
+
+const { default: unknownObject } = random > 0.5 ?
+    await import('./files/a.json', { assert: { type: "json" } }) :
+    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}`);
+
+const createMyServer = createServerHttp((_, res) => {
+    res.end('Request accepted');
+});
+
+export {
+    unknownObject,
+    createMyServer,
+};
+

src/streams/read.js

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+import path from "path";
+import fs from 'fs';
+import {getDirname} from "../common.js";
+
 export const read = async () => {
-    // Write your code here 
-};
+    const __dirname = getDirname(import.meta.url);
+    const filePath = path.join(__dirname, 'files', 'fileToRead.txt');
+    const readableStream = fs.createReadStream(filePath);
+    readableStream.pipe(process.stdout);
+};
+
+read();

src/streams/transform.js

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+import {pipeline, Transform} from 'stream'
+
 export const transform = async () => {
-    // Write your code here 
-};
+    const readableFromTerminal = process.stdin;
+    const writableToTerminal = process.stdout;
+    const transform = new Transform({
+        transform(chunk, _, callback) {
+            const chunkStringified = chunk.toString().trim();
+            const reversedChunk = chunkStringified.split('').reverse().join('');
+
+            callback(null, reversedChunk + '\n')
+        }
+    })
+
+    pipeline(
+        readableFromTerminal,
+        transform,
+        writableToTerminal,
+        err => {
+            if (err) console.log(err);
+        });
+};
+
+transform();