📚 COMP1531 Week 2 Study NotesCOMP1531 第2周学习笔记

🎯 Week 2 Overview第2周概览

Week 2 builds upon the foundation laid in Week 1, diving deeper into advanced JavaScript concepts, professional development practices, and essential team collaboration skills for software engineering projects. 第2周在第1周基础上深入学习高级JavaScript概念、专业开发实践和软件工程项目必备的团队协作技能。

🔧 2.2 Multi-file & Importing2.2 多文件编程与导入

📚 Importing Libraries导入库

JavaScript has built-in libraries that come with Node.js, similar to how C has standard libraries. These don't need to be installed separately. JavaScript有内置库随Node.js一起提供，类似于C的标准库。这些库无需单独安装。

#include <stdio.h>

int main() {
  printf("Hello\n");
}

import path from 'path';
console.log(path.resolve('./'));

🦸‍♂️ Importing Our Own Files导入自定义文件

We can separate logic into multiple files and import them, enabling better code organization and reusability. 我们可以将逻辑分离到多个文件并导入它们，实现更好的代码组织和复用性。

📤 Export Methods导出方法

// lib.js
function manyString(repeat, str) {
  let result = '';
  for (let i = 0; i < repeat; i++) {
    result += str;
  }
  return result;
}

export default manyString;

// main.js
import manyString from './lib.js';

// lib.js
function manyString(repeat, str) { ... }
function addBrackets(string) {
  return `(${string})`;
}

export {
  manyString,
  addBrackets,
};

// main.js
import { manyString, addBrackets } from './lib.js';

📦 2.3 Package Management with NPM2.3 使用NPM进行包管理

🧩 What is NPM?什么是NPM?

NPM (Node Package Manager) is automatically installed with Node.js and manages dependencies/modules/libraries for JavaScript projects. It allows you to download and use external libraries from the npmjs website. NPM（Node包管理器）与Node.js一同自动安装，管理JavaScript项目的依赖/模块/库。它允许您从npmjs网站下载和使用外部库。

🚀 Getting Started开始使用

npm init

npm install [package-name]

# Example:
npm install date-fns

📁 NPM File StructureNPM文件结构

✅ 3.3 Dynamic Verification & Testing3.3 动态验证与测试

👩‍🔬 Why Software Testing Matters软件测试的重要性

Software failures can be catastrophic and expensive. In 2016, software failures in the US cost $1.1 trillion and affected 4.4 billion customers. Testing helps prevent bugs, reduce development costs, and improve performance. 软件故障可能是灾难性和昂贵的。2016年，美国软件故障损失1.1万亿美元，影响44亿客户。测试有助于预防bug、降低开发成本并提高性能。

🐧 Black-box Testing & Abstraction黑盒测试与抽象

Great testing treats functions as "black boxes" - focus on inputs and outputs without worrying about internal implementation. This abstraction allows you to write tests even before implementing the function. 优秀的测试将函数视为"黑盒"——专注于输入和输出，不关心内部实现。这种抽象允许您甚至在实现函数之前就编写测试。

🤡 Jest Testing FrameworkJest测试框架

Jest is a popular JavaScript testing framework that provides structured testing capabilities with powerful matchers and descriptive output. Jest是流行的JavaScript测试框架，提供结构化测试能力，具有强大的匹配器和描述性输出。

📦 Installation & Setup安装与设置

# Install Jest as development dependency
npm install --save-dev jest

# Add test script to package.json
{
  "scripts": {
    "test": "jest"
  }
}

🏗️ Jest Test StructureJest测试结构

import { removeVowels } from './lib.js';

describe('removeVowels function', () => {
  test('handles strings with no vowels', () => {
    expect(removeVowels('bcd')).toEqual('bcd');
    expect(removeVowels('xyz')).toEqual('xyz');
  });

  test('removes all vowels correctly', () => {
    expect(removeVowels('hello')).toEqual('hll');
    expect(removeVowels('javascript')).toEqual('jvscrpt');
  });
});

🤝 2.1 How to Survive Group Projects2.1 团队项目生存指南

📋 Effective Meeting Management有效会议管理

⚡ Standups & Check-ins站会与签到

🎯 Ensuring Timely Delivery确保按时交付

🗺️ Week 2 Learning Path第2周学习路径

⚡ Quick Reference快速参考

npm init
npm install
npm install [package]
npm run [script]

export { func };
import { func } from './file.js';

export default func;
import func from './file.js';

describe('module', () => {
  test('behavior', () => {
    expect(result).toEqual(expected);
  });
});