text: 
  const path = require('path');
  const { createFilePath } = require('gatsby-source-filesystem')
  
  
  exports.onCreateNode = ({node, getNode, actions}) => {
      const { createNodeField } = actions;
  
      if(node.internal.type === 'MarkdownRemark') {
          const slug = createFilePath({node, getNode, basePath:'pages'})
  
          createNodeField({
              node,
              name: 'slug',
              value: slug
          })
      }
  }
  
  exports.createPages = async({graphql, actions}) => {
      const { createPage } = actions;
      const result = await graphql(`
          query {
              allMarkdownRemark {
                  edges {
                      node {
                      fields {
                          slug
                      }
                      }
                  }
              }
          }
      `)
      result.data.allMarkdownRemark.edges.forEach(({node}) => {
          createPage({
              path: node.fields.slug,
              component: path.resolve('./src/templates/blog-post.js'),
              context: {
                  slug: node.fields.slug
              }
          })
      })
  }