gatsby-config.js

const urljoin = require("url-join")
const siteConfig = require("./siteConfig")

require("dotenv").config({
  path: `.env.${process.env.NODE_ENV}`,
})

const contentfulConfig = {
  spaceId: process.env.CONTENTFUL_SPACE_ID,
  accessToken: process.env.CONTENTFUL_ACCESS_TOKEN,
}

const { spaceId, accessToken } = contentfulConfig

if (!spaceId || !accessToken) {
  throw new Error(
    "Contentful spaceId and the access token need to be provided."
  )
}

const googleAnalyticsConfig = {
  trackingId: process.env.GOOGLE_ANALYTICS_TRACKING_ID,
}

const { trackingId } = googleAnalyticsConfig

if (!trackingId) {
  throw new Error("Google analytics tracking id need to be provided.")
}

module.exports = {
  siteMetadata: {
    title: siteConfig.name,
    author: siteConfig.author,
    description: siteConfig.description,
    siteUrl: urljoin(siteConfig.url, siteConfig.prefix),
    social: {
      instagram: siteConfig.instagram,
      linkedin: siteConfig.linkedin,
    },
  },
  plugins: [
    {
      resolve: `gatsby-transformer-remark`,
      options: {
        plugins: [
          {
            resolve: `gatsby-remark-images`,
            options: {
              maxWidth: 1360,
              withWebp: true,
              showCaptions: true,
              quality: 75,
              wrapperStyle: `margin: 7vw 0;`,
            },
          },
          {
            resolve: `gatsby-remark-responsive-iframe`,
            options: {
              wrapperStyle: `margin-bottom: 1.0725rem`,
            },
          },
          `gatsby-remark-prismjs`,
          `gatsby-remark-copy-linked-files`,
          `gatsby-remark-smartypants`,
        ],
      },
    },
    `gatsby-transformer-sharp`,
    `gatsby-plugin-sharp`,
    {
      resolve: `gatsby-plugin-postcss`,
      options: {
        postCssPlugins: [
          require("postcss-easy-import")(),
          require("postcss-custom-properties")({ preserve: false }),
          require("postcss-color-function")(),
          // require("autoprefixer")({ browsers: ["last 2 versions"] }),
        ],
      },
    },
    "gatsby-plugin-sharp",
    {
      resolve: "gatsby-source-contentful",
      options: contentfulConfig,
    },
    {
      resolve: `gatsby-plugin-purgecss`,
      options: {
        printRejected: true, // Print removed selectors and processed file names
        develop: true, // Enable while using `gatsby develop`
        // tailwind: true, // Enable tailwindcss support
        // whitelist: ['whitelist'], // Don't remove this selector
        ignore: ["/src/utils/"], // Ignore files/folders
        // purgeOnly : ['components/', '/main.css', 'bootstrap/'], // Purge only these files/folders
      },
    },
    {
      resolve: `gatsby-plugin-google-analytics`,
      options: {
        trackingId: trackingId,
      },
    },
    `gatsby-plugin-netlify`,
    `gatsby-plugin-offline`,
    `gatsby-plugin-react-helmet`,
  ],
}