node.md

Node Ecosystem

Objectives

• Create an npm project
• Install npm packages
• Require npm packages
• Export and your own functions
• Add scripts to package.json

Create an npm project

• In an empty folder, initialize a new NPM project

Install npm packages

• Install lodash as a dependency
• Install live-server as a development dependency
• What is the difference between a depedency and a development dependency?
• What happens in the package.json file when a dependency is installed
• How do you install all current dependencies that are not installed?
• What is stored in node_modules?
• Why should you add node_modules to `.gitignore?

Require npm packages

• In the NPM project, create a file named app.js
• In app.js copy the following code

const array = [1,2,3,4,5,6,7,8,9]

• Require lodash, the console.log a shuffled array. https://lodash.com/docs/4.17.10#shuffle

Export and your own functions

• In the NPM project, create a file named shuffle.js, and add the following code

function shuffle(array){
  const arrayToShuffle = [...array]
  const result = []
  
  while(0 < arrayToShuffle.length){
    const randomIndex = Math.floor(Math.random() * arrayToShuffle.length)
    result.push(arrayToShuffle[randomIndex])

    arrayToShuffle.splice(randomIndex, 1)
  }

  return result
}

• Export the function shuffle
• Require your version of shuffle in app.js, and replace your usage of lodash shuffle

Add scripts to package.json

• In package.json, add a script that will run app.js using node

Exercise

• https://github.com/gSchool/colors-with-node