Task1

.prettierrc

@@ -0,0 +1,10 @@
+{
+  "singleQuote": true,
+  "trailingComma": "all",
+  "overrides": [
+    {
+      "files": ["**/.*rc", "**/*.json"],
+      "options": { "parser": "json" }
+    }
+  ]
+}

JavaScript/9-logger/config.js

@@ -0,0 +1,14 @@
+module.exports = {
+  transport: 'ws', // ws | http
+  apiPort: 8001,
+  staticPort: 8000,
+  staticPath: './static',
+  logPath: './log',
+  db: {
+    host: '127.0.0.1',
+    port: 5432,
+    database: 'example',
+    user: 'marcus',
+    password: 'marcus',
+  },
+};

JavaScript/9-logger/db.js

@@ -2,15 +2,7 @@
 
 const pg = require('pg');
 
-const pool = new pg.Pool({
-  host: '127.0.0.1',
-  port: 5432,
-  database: 'example',
-  user: 'marcus',
-  password: 'marcus',
-});
-
-module.exports = (table) => ({
+const createDBCrud = (pool) => (table) => ({
   async query(sql, args) {
     return await pool.query(sql, args);
   },
@@ -57,3 +49,5 @@ module.exports = (table) => ({
     return await pool.query(sql, [id]);
   },
 });
+
+module.exports = (poolOptions) => createDBCrud(new pg.Pool(poolOptions));

JavaScript/9-logger/http.js

@@ -2,30 +2,47 @@
 
 const http = require('node:http');
 
+const answerNotFound = (res, headers) => {
+  res.writeHead(404, headers);
+  res.end('Not found');
+};
+
 const receiveArgs = async (req) => {
   const buffers = [];
   for await (const chunk of req) buffers.push(chunk);
   const data = Buffer.concat(buffers).toString();
   return JSON.parse(data);
 };
 
-module.exports = (routing, port) => {
-  http.createServer(async (req, res) => {
-    const { url, socket } = req;
-    const [name, method, id] = url.substring(1).split('/');
-    const entity = routing[name];
-    if (!entity) return void res.end('Not found');
-    const handler = entity[method];
-    if (!handler) return void res.end('Not found');
-    const src = handler.toString();
-    const signature = src.substring(0, src.indexOf(')'));
-    const args = [];
-    if (signature.includes('(id')) args.push(id);
-    if (signature.includes('{')) args.push(await receiveArgs(req));
-    console.log(`${socket.remoteAddress} ${method} ${url}`);
-    const result = await handler(...args);
-    res.end(JSON.stringify(result.rows));
-  }).listen(port);
+module.exports = (routing, port, console) => {
+  http
+    .createServer(async (req, res) => {
+      const headers = {
+        'Access-Control-Allow-Origin':
+          '*' /* @dev First, read about security */,
+        'Access-Control-Allow-Methods': 'POST',
+        'Access-Control-Max-Age': 2592000, // 30 days
+        /** add other headers as per requirement */
+      };
+
+      const { url, socket } = req;
+      const [name, method, id] = url.substring(1).split('/');
+      const entity = routing[name];
+      if (!entity) return void answerNotFound(res, headers);
+      const handler = entity[method];
+      if (!handler) return void answerNotFound(res, headers);
+
+      res.writeHead(200, headers);
+      const src = handler.toString();
+      const signature = src.substring(0, src.indexOf(')'));
+      const args = [];
+      if (signature.includes('(id')) args.push(id);
+      args.push(...(await receiveArgs(req)));
+      console.log(`${socket.remoteAddress} ${req.method} ${url}`);
+      const result = await handler(...args);
+      res.end(JSON.stringify(result.rows));
+    })
+    .listen(port);
 
   console.log(`API on port ${port}`);
 };

JavaScript/9-logger/logger.js

@@ -68,4 +68,4 @@ class Logger {
   }
 }
 
-module.exports = new Logger('./log');
+module.exports = Logger;

JavaScript/9-logger/main.js

@@ -2,12 +2,16 @@
 
 const fsp = require('node:fs').promises;
 const path = require('node:path');
-const server = require('./ws.js');
 const staticServer = require('./static.js');
 const load = require('./load.js');
-const db = require('./db.js');
+const createDbQueryConstructor = require('./db.js');
 const hash = require('./hash.js');
-const logger = require('./logger.js');
+const Logger = require('./logger.js');
+const config = require('./config.js');
+const server = require(`./${config.transport}.js`);
+
+const logger = new Logger(config.logPath);
+const db = createDbQueryConstructor(config.db);
 
 const sandbox = {
   console: Object.freeze(logger),
@@ -26,6 +30,6 @@ const routing = {};
     routing[serviceName] = await load(filePath, sandbox);
   }
 
-  staticServer('./static', 8000);
-  server(routing, 8001);
+  staticServer(config.staticPath, config.staticPort, logger);
+  server(routing, config.apiPort, logger);
 })();

JavaScript/9-logger/package.json

@@ -6,7 +6,10 @@
   "private": true,
   "main": "main.js",
   "engines": {
-    "node": "14 || 16 || 18"
+    "node": "14 || 16 || 18 || 20"
+  },
+  "scripts": {
+    "start": "node --experimental-vm-modules main.js"
   },
   "dependencies": {
     "pg": "^8.8.0",

JavaScript/9-logger/static.js

@@ -4,18 +4,20 @@ const http = require('node:http');
 const path = require('node:path');
 const fs = require('node:fs');
 
-module.exports = (root, port) => {
-  http.createServer(async (req, res) => {
-    const url = req.url === '/' ? '/index.html' : req.url;
-    const filePath = path.join(root, url);
-    try {
-      const data = await fs.promises.readFile(filePath);
-      res.end(data);
-    } catch (err) {
-      res.statusCode = 404;
-      res.end('"File is not found"');
-    }
-  }).listen(port);
+module.exports = (root, port, console) => {
+  http
+    .createServer(async (req, res) => {
+      const url = req.url === '/' ? '/index.html' : req.url;
+      const filePath = path.join(root, url);
+      try {
+        const data = await fs.promises.readFile(filePath);
+        res.end(data);
+      } catch (err) {
+        res.statusCode = 404;
+        res.end('"File is not found"');
+      }
+    })
+    .listen(port);
 
   console.log(`Static on port ${port}`);
 };

JavaScript/9-logger/static/client.js

@@ -1,44 +1,86 @@
 'use strict';
 
-const socket = new WebSocket('ws://127.0.0.1:8001/');
+const API_URL = 'ws://localhost:8001';
 
-const scaffold = (structure) => {
+const getTransport = (url) => {
+  let socket;
+  const protocol = url.split(':')[0];
+
+  const transports = {
+    ws: (name, method) => {
+      if (!socket) socket = new WebSocket(url);
+      return (...args) => {
+        return new Promise((resolve) => {
+          const packet = { name, method, args };
+          socket.send(JSON.stringify(packet));
+          socket.onmessage = (event) => {
+            const data = JSON.parse(event.data);
+            resolve(data);
+          };
+        });
+      };
+    },
+
+    http:
+      (name, method, methodArgs) =>
+      (...args) => {
+        const urlParts = [url, name, method];
+        if (methodArgs[0] === 'id') urlParts.push(args.shift());
+
+        return fetch(urlParts.join('/'), {
+          method: 'POST',
+          body: JSON.stringify(args),
+        }).then((response) => response.json());
+      },
+  };
+
+  return transports[protocol];
+};
+
+const scaffold = (url, structure) => {
+  const transport = getTransport(url);
   const api = {};
   const services = Object.keys(structure);
   for (const serviceName of services) {
     api[serviceName] = {};
     const service = structure[serviceName];
     const methods = Object.keys(service);
     for (const methodName of methods) {
-      api[serviceName][methodName] = (...args) => new Promise((resolve) => {
-        const packet = { name: serviceName, method: methodName, args };
-        socket.send(JSON.stringify(packet));
-        socket.onmessage = (event) => {
-          const data = JSON.parse(event.data);
-          resolve(data);
-        };
-      });
+      api[serviceName][methodName] = transport(
+        serviceName,
+        methodName,
+        service[methodName],
+      );
     }
   }
   return api;
 };
 
-const api = scaffold({
+const api = scaffold(API_URL, {
   user: {
     create: ['record'],
     read: ['id'],
     update: ['id', 'record'],
     delete: ['id'],
     find: ['mask'],
   },
+  city: {
+    read: ['id'],
+    create: ['record'],
+    update: ['id', 'record'],
+    delete: ['id'],
+  },
   country: {
     read: ['id'],
+    create: ['record'],
+    update: ['id', 'record'],
     delete: ['id'],
-    find: ['mask'],
   },
 });
 
-socket.addEventListener('open', async () => {
-  const data = await api.user.read(3);
-  console.dir({ data });
-});
+// socket.addEventListener('open', async () => {
+//   const data = await api.user.read(3);
+//   console.dir({ data });
+// });
+
+(async () => console.log(await api.user.read(3)))();

JavaScript/9-logger/ws.js

@@ -1,9 +1,8 @@
 'use strict';
 
-const console = require('./logger.js');
 const { Server } = require('ws');
 
-module.exports = (routing, port) => {
+module.exports = (routing, port, console) => {
   const ws = new Server({ port });
 
   ws.on('connection', (connection, req) => {