Using Sass in Create React App v2

Introduction

With the upgraded Create React App released recently, we got a lot of new tools to play with. Sass is one that I’m excited to have built-in since we used to have .scss files compile and write to .css files right in our folder structure. Messy files when you have two of the same styles.scss and styles.css.

Create React App 2 makes it super easy to use Sass in 1 line.

You may be concerned about using Sass in React. Isn’t a smarter way to write styles with CSS-in-JS libraries like styled-components or aphrodite? I believe that adding Sass support to Create React App will be a big help to beginners of React. How do I use Sass in React is one of the questions I always hear from people getting into React. With the React 16.6 additions like React.memo() and the React 16.7 functional additions like hooks, starting with React will be easier than ever!

Quick Start

The steps to use Sass in Create React App are:

First, install node-sass

npm install node-sass -S

Then, change .css files to .scss

Finally, once we’ve changed the file name from .css to .scss, we can import the Sass:

// replace
import "./styles.css";

// with
import "./styles.scss";

Done! Create React App will know to parse your .scss files and add the styles to your project.

Using and Sharing Sass Variables

How do we share variables across files? We are able to import our Sass files from other Sass files. Let’s say you create a variables file:

variables.scss

$primaryColor: #BADA55;

We can import this inside of another file like we normally would in Sass:

styles.scss

// import starting from the src/ folder
@import "variables.scss";

// can also be relative import
// @import "./variables.scss";

// we can use the $primaryColor variable now
h1, h2 {
  color: $primaryColor;
}

Sass Files from 3rd Party Packages

If we want to use any 3rd party libraries like Bulma (currently my favorite) or Bootstrap, we don’t need to import the entire CSS library anymore.

With Sass in React, we can import just the files we need. First, we have to install Bulma.

npm install bulma -S

If we look at Bulma’s GitHub in the sass/ folder, we can see where they place their .sass files. Notice they are using .sass and we are using the .scss variant. No problems, node-sass can read and @import both!

Import files from node_modules using tilde (~).

The ~ let’s webpack and Create React App know to look in the node_modules/ folder for the files we need. Let’s add a few of the files we need to our app:

styles.scss

// import using ~
@import "~bulma/sass/utilities/_all.sass";
@import "~bulma/sass/base/_all.sass";
@import "~bulma/sass/elements/button.sass";
@import "~bulma/sass/layout/section.sass";

Now, we can use Bulma’s button and section.

App.js

function App() {
  return (
    <div className="App section">
      <h1>Hello CodeSandbox</h1>
      <h2>Start editing to see some magic happen!</h2>

      <button className="button is-danger is-outlined">
        Hello
      </button>
    </div>
  );
}

This approach lets us keep our CSS bundle sizes as small as possible as we only import what we need.

Conclusion

Using Sass in React is a quick way to get styling in your app. It is also recommended to look at CSS-in-JS solutions so that we can create even more modular CSS in our component-based React apps.

Here’s the CodeSandbox with the demo of Sass in Create React App 2:

https://codesandbox.io/s/j7y6wy9m09