Implement PrismJS in GatsbyJS.

I recently implemented PrismJS for code highlighting in GatsbyJS . Since there weren’t that many posts to do a quick installation here is how I did it.

Install PrismJS

First, install PrismJS and it’s Gatsby plugins:

npm install --save gatsby-transformer-remark gatsby-remark-prismjs prismjs

This will make sure that you have all the plugins needed. Next, go to your gatsby-config.js and put the following code after your declaration of gatsby-transformer-remark since this is a plugin it has to go in the plugins section like this:

// gatsby-config.js
resolve: `gatsby-transformer-remark`,
      options: {
        plugins: [
          {
            resolve: `gatsby-remark-prismjs`,
            options: {
              aliases:{sh: "bash", js:"javascript"},
              showLineNumbers: true,
            }
          }
        ],
      },

Choose a PrismJS Theme

After that you have to include the PrismJS theme you like in your Gatsby-browser.js file and also include the line numbers like that

// gatsby-browser.js
require("prismjs/themes/prism-tomorrow.css");
require("prismjs/plugins/line-numbers/prism-line-numbers.css");

Optional: Atom Editor Style

Since I didn’t really like the default themes that PrismJS comes with I looked for a one that I liked more. And I found my beloved Atom Editor Style in the additional themes that are available on GitHub. To include it install prism-themes with npm.

npm i prism-themes

And include change your gatsby-browser.js to this:

// gatsby-browser.js
require("prism-themes/themes/prism-atom-dark.css");
require("prismjs/plugins/line-numbers/prism-line-numbers.css");

Change your CSS

Because of the line numbers, there have to be changes in your CSS. Mine is in /components/layout.css. There you have to add the following lines to get everything in order:

.gatsby-highlight {
  background-color: #1d1f21;
  border-radius: 0.3em;
  margin: 0.5em 0;
  padding: 1em;
  overflow: auto;
}

.gatsby-highlight pre[class*="language-"].line-numbers {
  padding: 0;
  padding-left: 2.8em;
  overflow: initial;
}

That’s it. You just implemented PrismJS in GatsbyJS to highlight your code blocks with the Atom Editor Style.

PS: I also updated my GatsbyJS starter to use PrismJS.

Thank you for reading,
Niklas