gatsby-node.js

const path = require('path');

// remove duplicate pages generated by Gatsby for keeping subfolder organization, but not affecting SEO
exports.onCreatePage = ({ page, actions }) => {
  const { deletePage } = actions;
  if (
    page.path.startsWith('/main/') ||
    page.path.startsWith('/posts/') ||
    page.path.startsWith('/extras/') ||
    page.path.startsWith('/freelance-subpages/')
  ) {
    deletePage(page);
  }
};

exports.createPages = async ({ actions, graphql }) => {
  const { createPage } = actions;

  const result = await graphql(`
    {
      allMdx {
        nodes {
          id
          frontmatter {
            slug
          }
          internal {
            contentFilePath
          }
        }
      }
    }
  `);

  if (result.errors) {
    throw new Error(result.errors);
  }

  const excludedFiles = [
    'adventures_template.mdx',
    'research_template.mdx',
    'thoughts_template.mdx'
  ]

  // process mdx files of posts by checking if the contentFilePath includes 'src/pages/posts', but not excludedFiles
  result.data.allMdx.nodes.forEach((node) => {
    if ( excludedFiles.some((templateName) => node.internal.contentFilePath.includes(templateName)) ) { return }

    if (node.internal.contentFilePath.includes('src/pages/posts')) {

      const PostTemplate = process.env.NODE_ENV === "development"
        ? path.resolve(`./src/templates/post_development.js`)
        : path.resolve(`./src/templates/post.js`);

      const slug = node.frontmatter.slug;
      const slugParts = slug.split('/').filter(part => part !== '');
      const section = slugParts[0];
      const postName = slugParts[1];
      const postsFilterRegex = `/${section}/`;
      
      createPage({
        path: node.frontmatter.slug, 
        component: `${PostTemplate}?__contentFilePath=${node.internal.contentFilePath}`,
        context: { 
          id: node.id,
          postsFilterRegex,
          imagePathRegex: `^posts/${section}/content/${postName}/`,
        },
      });
    }
  });

  createPage({path: "/frog", component: path.resolve(`src/components/NotFound/index.js`)});
  createPage({path: "/adventures", component: path.resolve(`src/pages/main/adventures.js`)});
  createPage({path: "/research", component: path.resolve(`src/pages/main/research.js`)});
  createPage({path: "/thoughts", component: path.resolve(`src/pages/main/thoughts.js`)});
  createPage({path: "/tags", component: path.resolve(`src/pages/main/tags.js`)});
  createPage({path: "/handbook", component: path.resolve(`src/pages/main/travel_handbook.js`)});
  createPage({path: "/publications", component: path.resolve(`src/pages/main/publications.js`)});
  createPage({path: "/software", component: path.resolve(`src/pages/main/software.js`)});
  createPage({path: "/music", component: path.resolve(`src/pages/main/music.js`)});
  createPage({path: "/course", component: path.resolve(`src/pages/main/course.js`)});
  createPage({path: "/talks", component: path.resolve(`src/pages/main/talks.js`)});
  createPage({path: "/goals", component: path.resolve(`src/pages/main/goals.js`)});
  createPage({path: "/exploration", component: path.resolve(`src/pages/main/exploration.js`)});
  createPage({path: "/freelance", component: path.resolve(`src/pages/main/freelance.js`)});
  createPage({path: "/freelance/ru", component: path.resolve(`src/pages/main/freelance_ru.js`)});
  createPage({path: "/freelance/services", component: path.resolve(`src/pages/freelance-subpages/services.mdx`)});
  createPage({path: "/freelance/ru/services", component: path.resolve(`src/pages/freelance-subpages/services_ru.mdx`)});
  createPage({path: "/freelance/projects/machine_learning", component: path.resolve(`src/pages/freelance-subpages/machine_learning.js`)});
  createPage({path: "/freelance/ru/projects/machine_learning", component: path.resolve(`src/pages/freelance-subpages/machine_learning_ru.js`)});
  createPage({path: "/freelance/projects/data_analysis", component: path.resolve(`src/pages/freelance-subpages/data_analysis.js`)});
  createPage({path: "/freelance/ru/projects/data_analysis", component: path.resolve(`src/pages/freelance-subpages/data_analysis_ru.js`)});
  createPage({path: "/freelance/projects/data_visualization", component: path.resolve(`src/pages/freelance-subpages/data_visualization.js`)});
  createPage({path: "/freelance/ru/projects/data_visualization", component: path.resolve(`src/pages/freelance-subpages/data_visualization_ru.js`)});
  createPage({path: "/freelance/projects/data_collection", component: path.resolve(`src/pages/freelance-subpages/data_collection.js`)});
  createPage({path: "/freelance/ru/projects/data_collection", component: path.resolve(`src/pages/freelance-subpages/data_collection_ru.js`)});
  createPage({path: "/freelance/projects/python_apps", component: path.resolve(`src/pages/freelance-subpages/python_apps.js`)});
  createPage({path: "/freelance/ru/projects/python_apps", component: path.resolve(`src/pages/freelance-subpages/python_apps_ru.js`)});
  createPage({path: "/freelance/projects/web_development", component: path.resolve(`src/pages/freelance-subpages/web_development.js`)});
  createPage({path: "/freelance/ru/projects/web_development", component: path.resolve(`src/pages/freelance-subpages/web_development_ru.js`)});
  createPage({path: "/freelance/projects/research", component: path.resolve(`src/pages/freelance-subpages/research.js`)});
  createPage({path: "/freelance/ru/projects/research", component: path.resolve(`src/pages/freelance-subpages/research_ru.js`)});
  createPage({path: "/freelance/projects/technical_writing", component: path.resolve(`src/pages/freelance-subpages/technical_writing.js`)});
  createPage({path: "/freelance/ru/projects/technical_writing", component: path.resolve(`src/pages/freelance-subpages/technical_writing_ru.js`)});
  createPage({path: "/freelance/projects/post_production", component: path.resolve(`src/pages/freelance-subpages/post_production.js`)});
  createPage({path: "/freelance/ru/projects/post_production", component: path.resolve(`src/pages/freelance-subpages/post_production_ru.js`)});
  createPage({path: "/freelance/projects/misc", component: path.resolve(`src/pages/freelance-subpages/misc.js`)});
  createPage({path: "/freelance/ru/projects/misc", component: path.resolve(`src/pages/freelance-subpages/misc_ru.js`)});
  createPage({path: "/cv", component: path.resolve(`src/pages/main/cv.js`)});
  createPage({path: "/about", component: path.resolve(`src/pages/main/about.js`)});
  createPage({path: "/gallery", component: path.resolve(`src/pages/main/gallery.js`)});
  createPage({path: "/stories", component: path.resolve(`src/pages/main/stories.js`)});
  createPage({path: "/zettelkasten", component: path.resolve(`src/pages/main/zettelkasten.js`)});
  createPage({path: "/articles", component: path.resolve(`src/pages/main/articles.js`)});
  createPage({path: "/websites", component: path.resolve(`src/pages/main/websites.js`)});
  createPage({path: "/videos", component: path.resolve(`src/pages/main/videos.js`)});
  createPage({path: "/feed", component: path.resolve(`src/pages/main/feed.js`)});
  createPage({path: "/playlists", component: path.resolve(`src/pages/main/playlists.js`)});
  createPage({path: "/albums", component: path.resolve(`src/pages/main/albums.js`)});
  createPage({path: "/films", component: path.resolve(`src/pages/main/films.js`)});
  createPage({path: "/bookshelf", component: path.resolve(`src/pages/main/bookshelf.js`)});
  createPage({path: "/hall_of_fame", component: path.resolve(`src/pages/main/hall_of_fame.js`)});
  createPage({path: "/gear", component: path.resolve(`src/pages/main/gear.js`)});
  createPage({path: "/calisthenics", component: path.resolve(`src/pages/main/calisthenics.js`)});
  createPage({path: "/friends", component: path.resolve(`src/pages/main/friends.js`)});
  createPage({path: "/habits", component: path.resolve(`src/pages/main/habits.js`)});
  createPage({path: "/faq", component: path.resolve(`src/pages/main/faq.js`)});
  createPage({path: "/information_for_business_inquiries", component: path.resolve(`src/pages/extras/information_for_business_inquiries.js`)});
  createPage({path: "/donate", component: path.resolve(`src/pages/extras/donate.js`)});
  createPage({path: "/contact", component: path.resolve(`src/pages/extras/contact.js`)});
  createPage({path: "/all", component: path.resolve(`src/pages/extras/all_posts.js`)});
  createPage({path: "/dev", component: path.resolve(`src/pages/extras/dev.js`)});
  createPage({path: "/dev/null", component: path.resolve(`src/pages/extras/dev_null.js`)});
  createPage({path: "/dev/magnitoshakhtinsk", component: path.resolve(`src/pages/extras/dev_magnitoshakhtinsk.js`)});
  createPage({path: "/null", component: path.resolve(`src/pages/extras/dev_null.js`)});
  createPage({path: "/avrtt", component: path.resolve(`src/pages/extras/avrtt.js`)});

};