Week 1: JavaScript and TypeScript for Backend Development

This repository records the Week 1 learning work for JavaScript and TypeScript backend development. It progresses from language revision, through TypeScript features and project configuration, to a small Express API and an asynchronous API client utility.

Week 1 outcomes

Learning outcome	Evidence in this repository
Modern JavaScript and ES6+	Destructuring, spread syntax, template literals, optional chaining, and nullish coalescing in revision/js.
Promises, async/await, and errors	Promise examples and try/catch exercises in revision; asynchronous user services and route error handling in the backend.
TypeScript fundamentals	Interfaces, typed values, enums, a class, and a generic fetch utility.
TypeScript backend setup	A strict TypeScript/NodeNext Express project with a separated route, service, data, interface, and utility structure.
Practical task	A generic fetch-and-transform program that calls the local /users API exposed by the backend.

Project structure

week1/
├── practical/       # Generic asynchronous API utility
├── revision/        # JavaScript and TypeScript language exercises
│   ├── js/          # Plain JavaScript ES6+ revision
│   └── ts/          # Configured TypeScript revision project
└── tsbackend/       # Express API used by the practical exercise

The folders reflect the learning flow: revise JavaScript, apply the same concepts with TypeScript, build a small backend, and then consume that backend asynchronously.

Getting started

1. Run the backend first, following tsbackend/README.md.
2. Build and inspect the TypeScript revision exercises with revision/ts/README.md.
3. Review the API utility in practical/README.md.

Documentation map

• revision/README.md — language-revision exercises.
• revision/ts/README.md — the TypeScript revision project.
• tsbackend/README.md — setup, API routes, and backend design.
• practical/README.md — generic API utility and its current limitations.

Current practical-task note

The practical utility demonstrates API consumption by calling this repository's local Express API. A public third-party API has not yet been added. The practical also currently imports an interface with a .ts extension, which standard NodeNext TypeScript compilation rejects; see its README for the exact limitation and resolution.