Nodejs basics assignment

Readme.md

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

src/cli/args.js

@@ -1,5 +1,8 @@
 const parseArgs = () => {
-    // Write your code here 
+  const variables = Object.keys(process.env);
+  variables.forEach((v) => {
+    console.log(`${v} is ${process.env[v]},`);
+  });
 };
 
-parseArgs();
+parseArgs();

src/cli/env.js

@@ -1,5 +1,11 @@
 const parseEnv = () => {
-    // Write your code here 
+  const variables = Object.keys(process.env);
+  const prefix = "NVM";
+  variables.forEach((v) => {
+    if (v.startsWith(prefix)) {
+      console.log(`${v}=${process.env[v]};`);
+    }
+  });
 };
 
-parseEnv();
+parseEnv();

src/cp/cp.js

@@ -1,6 +1,13 @@
+import { fork, spawn } from "child_process";
+
 const spawnChildProcess = async (args) => {
-    // Write your code here
+  const child = fork("./files/script.js", args, {
+    stdio: ["pipe", "pipe", "pipe", "ipc"],
+  });
+
+  process.stdin.pipe(child.stdin);
+  child.stdout.pipe(process.stdout);
 };
 
 // Put your arguments in function call to test this functionality
-spawnChildProcess( /* [someArgument1, someArgument2, ...] */);
+spawnChildProcess(["someArgument1", "someArgument2"]);

src/fs/copy.js

@@ -1,5 +1,26 @@
+import fs from "fs";
+
 const copy = async () => {
-    // Write your code here 
+  fs.access("./files", function (error) {
+    if (error) {
+      // files does not exist.
+      throw new Error("FS operation failed");
+    }
+  });
+
+  fs.access("./files_copy", function (error) {
+    if (error) {
+      fs.cp("./files", "./files_copy", { recursive: true }, (err) => {
+        if (err) {
+          console.error(err);
+        }
+        console.log("Copied");
+      });
+      return;
+    }
+    // files_copy exists
+    throw new Error("FS operation failed");
+  });
 };
 
 await copy();

src/fs/create.js

@@ -1,5 +1,21 @@
+import fs from "fs";
+
 const create = async () => {
-    // Write your code here 
+  fs.access("./files/fresh.txt", fs.constants.F_OK, (error) => {
+    if (error) {
+      fs.appendFile(
+        "./files/fresh.txt",
+        "I am fresh and young",
+        function (err) {
+          if (err) throw err;
+          console.log("Saved!");
+        }
+      );
+      return;
+    }
+
+    throw new Error("FS operation failed");
+  });
 };
 
-await create();
+await create();

src/fs/delete.js

@@ -1,5 +1,19 @@
+import fs from "fs";
 const remove = async () => {
-    // Write your code here 
+  fs.access("./files/fileToRemove.txt", (error) => {
+    if (error) {
+      // fileToRemove does not exist.
+      throw new Error("FS operation failed");
+    }
+    fs.unlink("./files/fileToRemove.txt", (err) => {
+      if (err) {
+        console.error(`Error removing file: ${err}`);
+        return;
+      }
+
+      console.log(`successfully removed.`);
+    });
+  });
 };
 
-await remove();
+await remove();

src/fs/list.js

@@ -1,5 +1,18 @@
+import fs from "fs";
 const list = async () => {
-    // Write your code here 
+  fs.access("./files", (error) => {
+    if (error) {
+      // files does not exist.
+      throw new Error("FS operation failed");
+    }
+    fs.readdir("./files", (err, files) => {
+      let fileNames = [];
+      files.forEach((file) => {
+        fileNames.push(file);
+      });
+      console.log(fileNames);
+    });
+  });
 };
 
-await list();
+await list();

src/fs/read.js

@@ -1,5 +1,18 @@
+import fs from "fs";
 const read = async () => {
-    // Write your code here 
+  fs.access("./files/fileToRead.txt", (error) => {
+    if (error) {
+      // fileToRead does not exist.
+      throw new Error("FS operation failed");
+    }
+    fs.readFile("./files/fileToRead.txt", "utf8", (err, data) => {
+      if (err) {
+        console.error(err);
+        return;
+      }
+      console.log(data);
+    });
+  });
 };
 
-await read();
+await read();

src/fs/rename.js

@@ -1,5 +1,27 @@
+import fs from "fs";
+
 const rename = async () => {
-    // Write your code here 
+  fs.access("./files/wrongFilename.txt", function (error) {
+    if (error) {
+      // wrongFilename does not exist.
+      throw new Error("FS operation failed");
+    }
+  });
+
+  fs.access("./files/properFilename.md", function (error) {
+    if (error) {
+      fs.rename(
+        "./files/wrongFilename.txt",
+        "./files/properFilename.md",
+        () => {
+          console.log("File Renamed!");
+        }
+      );
+      return;
+    }
+    // properFilename exists
+    throw new Error("FS operation failed");
+  });
 };
 
-await rename();
+await rename();

src/hash/calcHash.js

@@ -1,5 +1,28 @@
+import { Writable } from "stream";
+import { createHash } from "crypto";
+import fs from "fs";
+
 const calculateHash = async () => {
-    // Write your code here 
+  fs.readFile("./files/fileToCalculateHashFor.txt", "utf8", (err, data) => {
+    if (err) {
+      console.error(err);
+      return;
+    }
+
+    let hashed = createHash("sha256").update("diyora").digest();
+    // one way
+    let toLog = Buffer.from(hashed).toString("hex");
+    console.log(toLog);
+
+    // second way
+    const hexStream = new Writable({
+      write(chunk, encoding, callback) {
+        console.log(chunk.toString("hex"));
+        callback();
+      },
+    });
+    hexStream.write(hashed);
+  });
 };
 
-await calculateHash();
+await calculateHash();

src/modules/cjsToEsm.mjs

@@ -0,0 +1,39 @@
+import "./files/c.js";
+
+import { release, version } from "os";
+
+import { createServer as createServerHttp } from "http";
+import path from "path";
+
+const random = Math.random();
+let unknownObject;
+
+(async () => {
+  if (random > 0.5) {
+    unknownObject = await import("./files/a.json", { with: { type: "json" } });
+    console.log("unknownObject", unknownObject);
+  } else {
+    unknownObject = await import("./files/b.json", { with: { type: "json" } });
+    console.log("unknownObject", unknownObject);
+  }
+})();
+
+console.log(`Release ${release()}`);
+console.log(`Version ${version()}`);
+console.log(`Path segment separator is "${path.sep}"`);
+
+console.log(`Path to current file is ${import.meta.filename}`);
+console.log(`Path to current directory is ${import.meta.dirname}`);
+
+const myServer = createServerHttp((_, res) => {
+  res.end("Request accepted");
+});
+
+const PORT = 3000;
+
+myServer.listen(PORT, () => {
+  console.log(`Server is listening on port ${PORT}`);
+  console.log("To terminate it, use Ctrl+C combination");
+});
+
+export { unknownObject, myServer };

src/streams/read.js

@@ -1,5 +1,13 @@
+import fs from "fs";
+
 const read = async () => {
-    // Write your code here 
+  const readableStream = fs.createReadStream("./files/fileToRead.txt", "utf8");
+
+  readableStream.on("error", function (error) {
+    console.log(`error: ${error.message}`);
+  });
+
+  readableStream.pipe(process.stdout);
 };
 
-await read();
+await read();

src/streams/transform.js

@@ -1,5 +1,18 @@
+import Transform from "stream";
+
 const transform = async () => {
-    // Write your code here 
+  function reverseInputText() {
+    const reverseStream = new Transform({
+      transform(chunk, encoding, callback) {
+        const reversedChunk = chunk.toString().split("").reverse().join("");
+        this.push(reversedChunk);
+        callback();
+      },
+    });
+  }
+  process.stdin.pipe(reverseInputText).pipe(process.stdout);
 };
 
-await transform();
+await transform();
+
+// I couldn't do it((

src/streams/write.js

@@ -1,5 +1,12 @@
+import fs from "fs";
+
 const write = async () => {
-    // Write your code here 
+  const writeStream = fs.createWriteStream("./files/fileToWrite.txt", "utf8");
+
+  process.stdin.on("data", (data) => {
+    writeStream.write(data);
+    process.exit();
+  });
 };
 
-await write();
+await write();