Reactive-Resume/gatsby-node.js

exports.onCreateWebpackConfig = ({ stage, actions, getConfig }) => {
  if (stage === 'build-javascript') {
    const config = getConfig();
    const miniCssExtractPlugin = config.plugins.find(
      (plugin) => plugin.constructor.name === 'MiniCssExtractPlugin',
    );
    if (miniCssExtractPlugin) {
      miniCssExtractPlugin.options.ignoreOrder = true;
    }
    actions.replaceWebpackConfig(config);
  }

  if (stage === 'build-html') {
    actions.setWebpackConfig({
      externals: [/^firebase/],
    });
  }
};

exports.onCreatePage = async ({ page, actions }) => {
  const { createPage } = actions;

  if (page.path.match(/^\/r/)) {
    page.matchPath = '/r/*';
    createPage(page);
  }
};