Node.js Notes

  1. Requiring and Including Modules
  2. Node Package Manager (NPM)
    1. Adding dependencies
    2. Running Scripts
    3. npx
  3. webpack

Requiring and Including Modules

https://medium.freecodecamp.org/requiring-modules-in-node-js-everything-you-need-to-know-e7fbd119be8

Write some code like this and save it in a file called bar.js

module.exports = {
  foo: function() {}
};

Then, require it and use it like this:

const bar = require('./foo.js');
bar.foo();

Notice that we use the ./. If you don't specify the path to a file, then node will search directories listed inside the module.paths variable.

Node Package Manager (NPM)

Use npm init to create a new project

Adding dependencies

Use npm install <foo> to install a library in local directory as a production dependency

Use npm -D install <foo> or npm install --save-dev <foo> to save as a dev dependency

Running Scripts

You can run the special lifecycle scripts like test, start, restart, stop by simply typing npm start, for example.

The behavior of each of these script commands is defined in package.json under the scripts section.

You can also add custom scripts, like for example you could define a repl script. But in order to run, use npm run repl.

npx

npx is a command line tool that comes with node to run command line tools like webpack. For example, you could either run npx webpack, or set up scripts with a build key so that you can run `npm run build to run webpack`.

webpack

When writing javascript for the front end, you often end up with several js files along with images, and css that you want to present in an html page. It can get tedious and cumbersome to create html files that include all the css/js/img files. webpack is a tool that helps with this. You tell webpack where all your js/css/js/html files are, and it combines them all to produce a final version to use.