Add exercise 3 for lesson 3

Author: visola

Lesson03/exercise_003/index.js

@@ -0,0 +1,51 @@
+const fs = require('fs');
+const http = require('http');
+const mime = require('mime');
+const path = require('path');
+const url = require('url');
+
+function walkDirectory(dirPath, callback) {
+  const dirents = fs.readdirSync(dirPath, { withFileTypes: true });
+
+  dirents.forEach(dirent => {
+    if (dirent.isDirectory()) {
+      walkDirectory(path.join(dirPath, dirent.name), callback);
+    } else {
+      callback(path.join(dirPath, dirent.name));
+    }
+  });
+}
+
+const rootDirectory = path.resolve(process.argv[2] || './');
+
+const files = new Set();
+walkDirectory(rootDirectory, (file) => {
+  file = file.substr(rootDirectory.length);
+  files.add(file);
+});
+console.log(`Found ${files.size} in '${rootDirectory}'...`);
+
+const server = http.createServer();
+server.on('request', (request, response) => {
+  const requestUrl = url.parse(request.url);
+  const requestedPath = requestUrl.pathname;
+  
+  if (!files.has(requestedPath)) {
+    console.log('404 %s', requestUrl.href);
+    response.writeHead(404);
+    response.end();
+    return;
+  }
+
+  const contentType = mime.getType(path.extname(requestedPath));
+
+  console.log('200 %s', requestUrl.href);
+  response.writeHead(200, { 'Content-type': contentType });
+  fs.createReadStream(path.join(rootDirectory, requestedPath))
+    .pipe(response);
+});
+
+const port = 3000;
+console.log('Starting server on port %d.', port);
+console.log('Go to: http://localhost:%d', port);
+server.listen(port);

Lesson03/exercise_003/package-lock.json

@@ -0,0 +1,19 @@
+{
+  "name": "exercise_003",
+  "version": "1.0.0",
+  "description": "Static HTTP server.",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/TrainingByPackt/Professional-JavaScript.git",
+    "directory": "Lesson03/exercise_003"
+  },
+  "author": "",
+  "license": "MIT",
+  "dependencies": {
+    "mime": "^2.4.4"
+  }
+}