01_typescript_intro.md

TypeScript intro

How to setup TypeScript and use in a normal JavaScript project for learning purposes.

Preparations

• mkdir lab-ts
• cd lab-ts
• git init
• touch .gitignore. Add node_modules and dist to the file.
• npm init --yes

Install TypeScript

• npm install typescript

Setup TypeScript

• npx tsc --init

Configure TypeScript

Inside tsconfig.json, set the following:

• "rootDir": "./src"
• "outDir": "./dist"

Verify that it works

• Create a folder src.
• Create a file src/index.ts.
• Write a console.log('Hello!'); statement inside the file.
• npx tsc
• Check the build output in the build folder.
• node build/index.js

02_jest_intro.md

Jest intro

How to setup Jest in a TypeScript project.

Preparations

Please do the TypeScript intro first.

Install Jest

• npm install jest @types/jest ts-jest

Setup Jest

• npx ts-jest config:init

Verify that it works

• Create a file index.test.ts.
• Write a test('It works!', () => {expect(1).toEqual(0);}); statement inside the file.
• npx jest
• The test should fail.