Learning TypeScript

Installation

Install nvm

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.36.0/install.sh | bash

Install Node.js

nvm install v12.18.3

nvm alias default v10.15.3

Upgrade npm

nvm use v12.18.3 --silent && npm install --global npm@6.14.7

Install TypeScript

npm install --global typescript@3.9.7

tsc --version

The tsc command is a console interface for the TypeScript compiler. This command allows you to compile your TypeScript files into JavaScript files.

Introduction to tsconfig.json

A TypeScript project does not have to contain a tsconfig.json file. However, most editors rely on this file to recognize a TypeScript project with specified configurations and to provide related features.

A tsconfig.json file accepts three fields: compilerOptions, files, and exclude.

Adding source map support

Source maps can help a lot while debugging, no matter for a debugger or for error stack traces from a log.

To have source map support, we need to enable the sourceMap compiler option in tsconfig.json.

Downloading declarations using typings

JavaScript has a large and booming ecosystem. As the bridge connecting TypeScript and other JavaScript libraries and frameworks, declaration files are playing a very important role.

With the help of declaration files, TypeScript developers can use existing JavaScript libraries with nearly the same experience as libraries written in TypeScript.

Thanks to the efforts of the TypeScript community, almost every popular JavaScript library or framework got its declaration files on a project called DefinitelyTyped.

Installing typings

typings is just another Node.js package with a command-line interface like TypeScript compiler.

Downloading declaration files

Testing with Mocha and Istanbul

Mocha and Chai

Mocha has been one of the most popular test frameworks for JavaScript, while Chai.js is a good choice as an assertion library.

j3rrywan9 / typescript-study