// Example TypeScript file: example2.ts
// This file demonstrates more advanced TypeScript features and patterns.
// Update marker 1
(() => {
// --- Types and Interfaces ---
type UUID = string;
interface Task {
id: UUID;
title: string;
completed: boolean;
dueDate?: Date;
}
interface Project {
id: UUID;
name: string;
tasks: Task[];
}
// --- Enums ---
enum TaskStatus {
TODO = 'todo',
IN_PROGRESS = 'in_progress',
DONE = 'done',
}
// --- Classes ---
class TaskManager {
private tasks: Map<UUID, Task> = new Map();
private listeners: { [event: string]: Function[] } = {};
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addTask(task: Task) {
this.tasks.set(task.id, task);
this.emit('taskAdded', task);
}
completeTask(id: UUID) {
const task = this.tasks.get(id);
if (task) {
task.completed = true;
this.emit('taskCompleted', task);
}
}
getTasks(): Task[] {
return Array.from(this.tasks.values());
}
getPendingTasks(): Task[] {
return this.getTasks().filter(t => !t.completed);
}
removeTask(id: UUID) {
this.tasks.delete(id);
this.emit('taskRemoved', id);
}
on(event: string, listener: Function) {
if (!this.listeners[event]) {
this.listeners[event] = [];
}
this.listeners[event].push(listener);
}
emit(event: string, ...args: any[]) {
if (this.listeners[event]) {
for (const listener of this.listeners[event]) {
listener(...args);
}
}
}
}
// --- Utility Functions ---
function generateUUID(): UUID {
return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, c => {
const r = Math.random() * 16 | 0, v = c === 'x' ? r : (r & 0x3 | 0x8);
return v.toString(16);
});
}
function createTask(title: string, dueDate?: Date): Task {
return {
id: generateUUID(),
title,
completed: false,
dueDate,
};
}
function createProject(name: string): Project {
return {
id: generateUUID(),
name,
tasks: [],
};
}
// --- Example Data ---
const project = createProject('AI Project');
const task1 = createTask('Design API', new Date('2024-07-01'));
const task2 = createTask('Implement backend');
const task3 = createTask('Write tests', new Date('2024-07-10'));
project.tasks.push(task1, task2, task3);
// --- Task Manager Usage ---
const manager = new TaskManager();
manager.on('taskAdded', (task: Task) => {
console.log(`Task added: ${task.title}`);
});
manager.on('taskCompleted', (task: Task) => {
console.log(`Task completed: ${task.title}`);
});
manager.on('taskRemoved', (id: UUID) => {
console.log(`Task removed: ${id}`);
});
for (const t of project.tasks) {
manager.addTask(t);
}
manager.completeTask(task1.id);
manager.removeTask(task2.id);
console.log('Pending tasks:', manager.getPendingTasks().map(t => t.title));
// --- Advanced Types ---
type TaskMap = Record<UUID, Task>;
type ProjectWithStatus = Project & { status: TaskStatus };
// --- Example of Type Guards ---
function isProject(obj: any): obj is Project {
return obj && typeof obj.id === 'string' && Array.isArray(obj.tasks);
}
// --- Example of Promises and Async/Await ---
async function fetchProject(id: UUID): Promise<Project> {
// Simulate async fetch
// Update marker 3
return new Promise(resolve => {
setTimeout(() => {
resolve(createProject('Fetched Project'));
}, 100);
});
}
// --- Example of Generics ---
function wrapInArray<T>(item: T): T[] {
return [item];
}
// --- Example of Decorators ---
function logClass(target: Function) {
console.log(`Class created: ${target.name}`);
}
@logClass
class Service {
name: string;
constructor(name: string) {
this.name = name;
}
start() {
console.log(`${this.name} started`);
}
}
const service = new Service('NotificationService');
service.start();
// --- Example of Static Methods ---
class MathUtils {
static add(a: number, b: number): number {
return a + b;
}
static multiply(a: number, b: number): number {
return a * b;
}
}
console.log('Math add:', MathUtils.add(2, 3));
console.log('Math multiply:', MathUtils.multiply(4, 5));
// --- End of File ---
// Update marker 4
})();
