HowProgrammingWorks · tshemsedinov · Jul 1, 2025 · Jul 1, 2025 · Jul 1, 2025 · Jul 1, 2025
diff --git a/Enterprise/package.json b/Enterprise/package.json
@@ -0,0 +1,3 @@
+{
+  "type": "module"
+}
diff --git a/Enterprise/static/404.html b/Enterprise/static/404.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset="utf-8">
+    <title>Error 404: File not found</title>
+    <link rel="stylesheet" href="styles/styles.css">
+  </head>
+  <body>
+    <h1>File not found</h1>
+  </body>
+</html>
diff --git a/Enterprise/static/application.js b/Enterprise/static/application.js
@@ -0,0 +1,68 @@
+import { Database } from './database.js';
+import { UserRepository, UserService } from './user.js';
+
+class Logger {
+  #output;
+
+  constructor(outputId) {
+    this.#output = document.getElementById(outputId);
+  }
+
+  log(...args) {
+    const lines = args.map(Logger.#serialize);
+    this.#output.textContent += lines.join(' ') + '\n';
+    this.#output.scrollTop = this.#output.scrollHeight;
+  }
+
+  static #serialize(x) {
+    return typeof x === 'object' ? JSON.stringify(x, null, 2) : x;
+  }
+}
+
+const logger = new Logger('output');
+
+const action = (id, handler) => {
+  const element = document.getElementById(id);
+  if (element) element.onclick = handler;
+};
+
+const db = new Database('EnterpriseApplication', 1, (db) => {
+  if (!db.objectStoreNames.contains('user')) {
+    db.createObjectStore('user', { keyPath: 'id', autoIncrement: true });
+  }
+});
+await db.connect();
+const userRepository = new UserRepository(db, 'user');
+const userService = new UserService(userRepository);
+
+action('add', async () => {
+  const name = prompt('Enter user name:');
+  const age = parseInt(prompt('Enter age:'), 10);
+  if (!name || !Number.isInteger(age)) return;
+  const user = await userService.createUser(name, age);
+  logger.log('Added:', user);
+});
+
+action('get', async () => {
+  const users = await userRepository.getAll();
+  logger.log('Users:', users);
+});
+
+action('update', async () => {
+  try {
+    const user = await userService.incrementAge(1);
+    logger.log('Updated:', user);
+  } catch (err) {
+    logger.log(err.message);
+  }
+});
+
+action('delete', async () => {
+  await userRepository.delete(2);
+  logger.log('Deleted user with id=2');
+});
+
+action('adults', async () => {
+  const adults = await userService.findAdults();
+  logger.log('Adults:', adults);
+});
diff --git a/Enterprise/static/core.js b/Enterprise/static/core.js
@@ -0,0 +1,50 @@
+export class Repository {
+  constructor(database, storeName) {
+    this.db = database;
+    this.storeName = storeName;
+  }
+
+  insert(record) {
+    return this.db.exec(this.storeName, 'readwrite', (store) =>
+      store.add(record),
+    );
+  }
+
+  getAll() {
+    return this.db.exec(this.storeName, 'readonly', (store) => {
+      const req = store.getAll();
+      return new Promise((resolve, reject) => {
+        req.onsuccess = () => resolve(req.result);
+        req.onerror = () => reject(req.error);
+      });
+    });
+  }
+
+  get(id) {
+    return this.db.exec(this.storeName, 'readonly', (store) => {
+      const req = store.get(id);
+      return new Promise((resolve, reject) => {
+        req.onsuccess = () => resolve(req.result);
+        req.onerror = () => reject(req.error);
+      });
+    });
+  }
+
+  update(record) {
+    return this.db.exec(this.storeName, 'readwrite', (store) =>
+      store.put(record),
+    );
+  }
+
+  delete(id) {
+    return this.db.exec(this.storeName, 'readwrite', (store) =>
+      store.delete(id),
+    );
+  }
+}
+
+export class Service {
+  constructor(repository) {
+    this.repository = repository;
+  }
+}
diff --git a/Enterprise/static/database.js b/Enterprise/static/database.js
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+export class Database {
+  #db;
+
+  constructor(name, version = 1, upgradeCallback) {
+    this.name = name;
+    this.version = version;
+    this.upgradeCallback = upgradeCallback;
+  }
+
+  async connect() {
+    return new Promise((resolve, reject) => {
+      const request = indexedDB.open(this.name, this.version);
+
+      request.onupgradeneeded = (event) => {
+        const db = event.target.result;
+        if (this.upgradeCallback) this.upgradeCallback(db);
+      };
+
+      request.onsuccess = () => {
+        this.#db = request.result;
+        resolve();
+      };
+
+      request.onerror = () => reject(request.error);
+    });
+  }
+
+  transaction(storeName, mode = 'readonly') {
+    const tx = this.#db.transaction(storeName, mode);
+    return tx.objectStore(storeName);
+  }
+
+  exec(storeName, mode, operation) {
+    return new Promise((resolve, reject) => {
+      try {
+        const tx = this.#db.transaction(storeName, mode);
+        const store = tx.objectStore(storeName);
+        const result = operation(store);
+        tx.oncomplete = () => resolve(result);
+        tx.onerror = () => reject(tx.error);
+      } catch (err) {
+        reject(err);
+      }
+    });
+  }
+}
diff --git a/Enterprise/static/favicon.ico b/Enterprise/static/favicon.ico
diff --git a/Enterprise/static/index.html b/Enterprise/static/index.html
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8" />
+  <title>IndexedDB Exampe</title>
+  <link rel="stylesheet" href="styles.css" />
+</head>
+<body>
+  <h1>IndexedDB Repository Example</h1>
+  <div class="controls">
+    <button id="add">Add User</button>
+    <button id="get">Get All Users</button>
+    <button id="update">Update User 1</button>
+    <button id="delete">Delete User 2</button>
+    <button id="adults">Find Adults</button>
+  </div>
+  <pre id="output"></pre>
+  <script type="module" src="./application.js"></script>
+</body>
+</html>
diff --git a/Enterprise/static/styles.css b/Enterprise/static/styles.css
@@ -0,0 +1,37 @@
+body {
+  font-family: system-ui, sans-serif;
+  padding: 1rem;
+  background: #f4f4f4;
+  color: #222;
+}
+
+h1 {
+  margin-bottom: 1rem;
+}
+
+.controls {
+  margin-bottom: 1rem;
+}
+
+button {
+  margin-right: 0.5rem;
+  padding: 0.5rem 1rem;
+  font-size: 1rem;
+  cursor: pointer;
+}
+
+pre#output {
+  position: fixed;
+  top: 10rem;
+  bottom: 0;
+  left: 0;
+  right: 0;
+  overflow: auto;
+  margin: 0;
+  padding: 1rem;
+  background: #111;
+  color: #0f0;
+  font-family: monospace;
+  font-size: 0.9rem;
+  white-space: pre-wrap;
+}
diff --git a/Enterprise/static/user.js b/Enterprise/static/user.js
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+import { Repository, Service } from './core.js';
+
+export class UserModel {
+  constructor(name, age) {
+    if (typeof name !== 'string' || name.trim().length === 0) {
+      throw new Error('Invalid name');
+    }
+    if (!Number.isInteger(age) || age < 0) {
+      throw new Error('Invalid age');
+    }
+    this.name = name.trim();
+    this.age = age;
+  }
+}
+
+export class UserRepository extends Repository {
+  constructor(database) {
+    super(database, 'user');
+  }
+}
+
+export class UserService extends Service {
+  async createUser(name, age) {
+    const user = new UserModel(name, age);
+    await this.repository.insert(user);
+    return user;
+  }
+
+  async incrementAge(id) {
+    const user = await this.repository.get(id);
+    if (!user) throw new Error('User with id=1 not found');
+    user.age += 1;
+    await this.repository.update(user);
+    return user;
+  }
+
+  async findAdults() {
+    const users = await this.repository.getAll();
+    return users.filter((user) => user.age >= 18);
+  }
+}
diff --git a/Enterprise/test/core.js b/Enterprise/test/core.js
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+import test from 'node:test';
+import assert from 'node:assert/strict';
+import 'fake-indexeddb/auto';
+import { Database } from '../static/database.js';
+import { Repository, Service } from '../static/core.js';
+
+test('Enterprise: Repository', async () => {
+  const db = new Database('RepoTestDB', 1, (db) => {
+    db.createObjectStore('items', { keyPath: 'id', autoIncrement: true });
+  });
+  await db.connect();
+
+  const repo = new Repository(db, 'items');
+
+  const item = { name: 'Item1' };
+  await repo.insert(item);
+
+  const items = await repo.getAll();
+  assert.equal(items.length, 1);
+  assert.equal(items[0].name, 'Item1');
+
+  const id = items[0].id;
+  const one = await repo.get(id);
+  assert.equal(one.name, 'Item1');
+
+  one.name = 'Item1Updated';
+  await repo.update(one);
+
+  const updated = await repo.get(id);
+  assert.equal(updated.name, 'Item1Updated');
+
+  await repo.delete(id);
+  const afterDelete = await repo.getAll();
+  assert.equal(afterDelete.length, 0);
+});
+
+test('Enterprise: Service', () => {
+  const fakeRepo = { insert: () => {}, get: () => {} };
+  const service = new Service(fakeRepo);
+  assert.equal(service.repository, fakeRepo);
+});
diff --git a/Enterprise/test/database.js b/Enterprise/test/database.js
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+import test from 'node:test';
+import assert from 'node:assert/strict';
+import 'fake-indexeddb/auto';
+import { Database } from '../static/database.js';
+import { Repository, Service } from '../static/core.js';
+import { UserModel, UserRepository, UserService } from '../static/user.js';
+
+test('Enterprise: Database CRUD + queries', async () => {
+  const db = new Database('TestDB', 1, (db) => {
+    if (!db.objectStoreNames.contains('user')) {
+      db.createObjectStore('user', { keyPath: 'id', autoIncrement: true });
+    }
+  });
+  await db.connect();
+
+  const repo = new Repository(db, 'user');
+  const marcus = new UserModel('Marcus', 28);
+
+  await repo.insert(marcus);
+  const allUsers = await repo.getAll();
+  assert.equal(allUsers.length, 1);
+  assert.equal(allUsers[0].name, 'Marcus');
+
+  const user = await repo.get(1);
+  user.age = 29;
+  await repo.update(user);
+
+  const updated = await repo.get(1);
+  assert.equal(updated.age, 29);
+
+  await repo.delete(1);
+  const empty = await repo.getAll();
+  assert.equal(empty.length, 0);
+});