gatsby-node.js

exports.createPages = async function ({ actions, graphql }) {
  const postTemplate = require.resolve("./src/templates/allPosts.js");
  const data = await graphql(`
    query {
      allMdx(sort: { fields: frontmatter___date, order: DESC }) {
        edges {
          node {
            frontmatter {
              slug
            }
            id
          }
        }
      }
    }
  `);

  //create paginated pages for posts

  const postPerPage = 3;
  const numPages = Math.ceil(data.data.allMdx.edges.length / postPerPage);

  Array.from({ length: numPages }).forEach((_, i) => {
    actions.createPage({
      path: i === 0 ? `/` : `/${i + 1}`,
      component: postTemplate,
      context: {
        limit: postPerPage,
        skip: i * postPerPage,
        numPages,
        currentPage: i + 1,
      },
    });
  });

  //create single blog post

  data.data.allMdx.edges.forEach((edge) => {
    const slug = edge.node.frontmatter.slug;
    const id = edge.node.id;

    actions.createPage({
      path: slug,
      component: require.resolve("./src/templates/singlePost.js"),
      context: { id },
    });
  });
};