Initial commit 🚀

2-how-node-works/final/event-loop.js

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+const fs = require("fs");
+const crypto = require("crypto");
+
+const start = Date.now();
+process.env.UV_THREADPOOL_SIZE = 4;
+
+setTimeout(() => console.log("Timer 1 finished"), 0);
+setImmediate(() => console.log("Immediate 1 finished"));
+
+fs.readFile("test-file.txt", () => {
+  console.log("I/O finished");
+  console.log("----------------");
+
+  setTimeout(() => console.log("Timer 2 finished"), 0);
+  setTimeout(() => console.log("Timer 3 finished"), 3000);
+  setImmediate(() => console.log("Immediate 2 finished"));
+
+  process.nextTick(() => console.log("Process.nextTick"));
+
+  crypto.pbkdf2Sync("password", "salt", 100000, 1024, "sha512");
+  console.log(Date.now() - start, "Password encrypted");
+
+  crypto.pbkdf2Sync("password", "salt", 100000, 1024, "sha512");
+  console.log(Date.now() - start, "Password encrypted");
+
+  crypto.pbkdf2Sync("password", "salt", 100000, 1024, "sha512");
+  console.log(Date.now() - start, "Password encrypted");
+
+  crypto.pbkdf2Sync("password", "salt", 100000, 1024, "sha512");
+  console.log(Date.now() - start, "Password encrypted");
+});
+
+console.log("Hello from the top-level code");

2-how-node-works/final/events.js

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+const EventEmitter = require("events");
+const http = require("http");
+
+class Sales extends EventEmitter {
+  constructor() {
+    super();
+  }
+}
+
+const myEmitter = new Sales();
+
+myEmitter.on("newSale", () => {
+  console.log("There was a new sale!");
+});
+
+myEmitter.on("newSale", () => {
+  console.log("Costumer name: Jonas");
+});
+
+myEmitter.on("newSale", stock => {
+  console.log(`There are now ${stock} items left in stock.`);
+});
+
+myEmitter.emit("newSale", 9);
+
+//////////////////
+
+const server = http.createServer();
+
+server.on("request", (req, res) => {
+  console.log("Request received!");
+  console.log(req.url);
+  res.end("Request received");
+});
+
+server.on("request", (req, res) => {
+  console.log("Another request 😀");
+});
+
+server.on("close", () => {
+  console.log("Server closed");
+});
+
+server.listen(8000, "127.0.0.1", () => {
+  console.log("Waiting for requests...");
+});

2-how-node-works/final/modules.js

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+// console.log(arguments);
+// console.log(require("module").wrapper);
+
+// module.exports
+const C = require("./test-module-1");
+const calc1 = new C();
+console.log(calc1.add(2, 5));
+
+// exports
+// const calc2 = require("./test-module-2");
+const { add, multiply } = require("./test-module-2");
+console.log(multiply(2, 5));
+
+// caching
+require("./test-module-3")();
+require("./test-module-3")();
+require("./test-module-3")();

2-how-node-works/final/streams.js

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+const fs = require("fs");
+const server = require("http").createServer();
+
+server.on("request", (req, res) => {
+  // Solution 1
+  // fs.readFile("test-file.txt", (err, data) => {
+  //   if (err) console.log(err);
+  //   res.end(data);
+  // });
+
+  // Solution 2: Streams
+  // const readable = fs.createReadStream("test-file.txt");
+  // readable.on("data", chunk => {
+  //   res.write(chunk);
+  // });
+  // readable.on("end", () => {
+  //   res.end();
+  // });
+  // readable.on("error", err => {
+  //   console.log(err);
+  //   res.statusCode = 500;
+  //   res.end("File not found!");
+  // });
+
+  // Solution 3
+  const readable = fs.createReadStream("test-file.txt");
+  readable.pipe(res);
+  // readableSource.pipe(writeableDest)
+});
+
+server.listen(8000, "127.0.0.1", () => {
+  console.log("Listening...");
+});

2-how-node-works/final/test-module-1.js

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+// class Calculator {
+//   add(a, b) {
+//     return a + b;
+//   }
+
+//   multiply(a, b) {
+//     return a * b;
+//   }
+
+//   divide(a, b) {
+//     return a / b;
+//   }
+// }
+
+module.exports = class {
+  add(a, b) {
+    return a + b;
+  }
+
+  multiply(a, b) {
+    return a * b;
+  }
+
+  divide(a, b) {
+    return a / b;
+  }
+};

2-how-node-works/final/test-module-2.js

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+exports.add = (a, b) => a + b;
+exports.multiply = (a, b) => a * b;
+exports.divide = (a, b) => a / b;

2-how-node-works/final/test-module-3.js

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+console.log("Hello from the module");
+
+module.exports = () => console.log("Log this beautiful text 😍");