Gatsby.js blog is appending '/blog' twice to a post – SEO

I have an index route with a view posts link. On the posts page the posts are all showing the title links but using the netflify CMS today when I was writing another blog post I noticed now the posts page shows the individual post links to localhost:8000/blog/blog/{the-post-name}. If I remove one of the ‘blog’ parts from the url the associated post loads correctly. I just do not understand why this is occurring as the site was working fine earlier.

The issue seems to be related to {node.fields.slug} incorrectly linking

Any help is appreciated!

gatsby-config

module.exports = {
  siteMetadata: {
    // edit below
    title: `Front-end Developer`,
    author: `Alex Virdee`,
    description: `A starter personal blog with styled components, dark mode, and Netlify CMS.`,
    siteUrl: `https://hungry-bassi-27b875.netlify.app/`,
    social: {
      twitter: `alex_virdee`,
    },
  },
  plugins: [
    `gatsby-plugin-netlify-cms`,
    `gatsby-plugin-styled-components`,
    `gatsby-transformer-sharp`,
    `gatsby-plugin-sharp`,
    `gatsby-plugin-offline`,
    `gatsby-plugin-react-helmet`,
    `gatsby-plugin-feed-mdx`,
    {
      resolve: `gatsby-source-filesystem`,
      options: {
        path: `${__dirname}/content/blog`,
        name: `blog`,
      },
    },
    {
      resolve: `gatsby-source-filesystem`,
      options: {
        path: `${__dirname}/content/assets`,
        name: `assets`,
      },
    },
    {
      resolve: `gatsby-source-filesystem`,
      options: {
        name: `img`,
        path: `${__dirname}/static`
      }
    },
    {
      resolve: `gatsby-plugin-mdx`,
      options: {
        extensions: [".mdx", ".md"],
        gatsbyRemarkPlugins: [
          {
            resolve: `gatsby-remark-images`,
            options: {
              maxWidth: 590,
            },
          },
          {
            resolve: `gatsby-remark-responsive-iframe`,
            options: {
              wrapperStyle: `margin-bottom: 1.0725rem`,
            },
          },
          {
            resolve: `gatsby-remark-vscode`,
          },
          {
            resolve: `gatsby-remark-copy-linked-files`,
          },
          {
            resolve: `gatsby-remark-smartypants`,
          },
        ],
        plugins: [`gatsby-remark-images`],
      },
    },
    {
      resolve: `gatsby-plugin-google-analytics`,
      options: {
        // edit below
        // trackingId: `ADD YOUR TRACKING ID HERE`,
      },
    },
    {
      resolve: `gatsby-plugin-manifest`,
      options: {
        name: `Gatsby Starter Blog`,
        short_name: `GatsbyJS`,
        start_url: `/`,
        background_color: `#ffffff`,
        theme_color: `#663399`,
        display: `minimal-ui`,
        // edit below
        icon: `content/assets/gatsby-icon.png`,
      },
    },
    {
      resolve: `gatsby-plugin-typography`,
      options: {
        pathToConfigModule: `src/utils/typography`,
      },
    },
  ],
}

gatsby-node

const path = require(`path`)
const { createFilePath } = require(`gatsby-source-filesystem`)

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

  const blogPost = path.resolve(`./src/templates/blog-post.js`)
  return graphql(
    `
      {
        allMdx(
          sort: { fields: [frontmatter___date], order: DESC }
          limit: 1000
        ) {
          edges {
            node {
              fields {
                slug
              }
              frontmatter {
                title
              }
            }
          }
        }
      }
    `
  ).then(result => {
    if (result.errors) {
      throw result.errors
    }

    // Create blog posts pages.
    const posts = result.data.allMdx.edges

    posts.forEach((post, index) => {
      const previous = index === posts.length - 1 ? null : posts[index + 1].node
      const next = index === 0 ? null : posts[index - 1].node

      createPage({
        path: `blog${post.node.fields.slug}`,
        component: blogPost,
        context: {
          slug: post.node.fields.slug,
          previous,
          next,
        },
      })
    })

    return null
  })
}

exports.onCreateNode = ({ node, actions, getNode }) => {
  const { createNodeField } = actions

  if (node.internal.type === `Mdx`) {
    const value = createFilePath({ node, getNode })
    createNodeField({
      name: `slug`,
      node,
      value,
    })
  }
}

layout.js

import React from "react"
import { Link } from "gatsby"
import styled from "styled-components"

import { rhythm, scale } from "../utils/typography"

class Layout extends React.Component {
  render() {
    const { location, title, children } = this.props
    const rootPath = `${__PATH_PREFIX__}/`
    const blogPath = `${__PATH_PREFIX__}/blog/`
    let header

    if (location.pathname === rootPath || location.pathname === blogPath) {
      header = (
        <h1
          style={{
            ...scale(1.4),
            marginBottom: rhythm(1.2),
            marginTop: 0,
          }}
        >
          <Link
            style={{
              boxShadow: `none`,
              textDecoration: `none`,
              color: `inherit`,
            }}
            to={location.pathname === blogPath ? `/blog/` : `/`}
          >
            {title}
          </Link>
        </h1>
      )
    } else {
      header = (
        <h3
          style={{
            fontFamily: `Montserrat, sans-serif`,
            marginTop: 0,
          }}
        >
          <Link
            style={{
              boxShadow: `none`,
              textDecoration: `none`,
              color: `inherit`,
            }}
            to={`/blog/`}
          >
            {title}
          </Link>
        </h3>
      )
    }
    return (
      <Wrapper>
        <div
          style={{
            marginLeft: `auto`,
            marginRight: `auto`,
            maxWidth: rhythm(24),
            padding: `${rhythm(1.5)} ${rhythm(3 / 4)}`,
          }}
        >
          <header>{header}</header>
          <main>{children}</main>
        </div>
        <Footer>
          Built by
          {` `}
         Alex Virdee  © {new Date().getFullYear()}

        </Footer>
      </Wrapper>
    )
  }
}

const Wrapper = styled.div`
  min-height: 100vh;
`

const Footer = styled.footer`
  text-align: center;
  margin: 24px;
`

export default Layout

Blog page that shows the links to individual posts

import React from "react"
import { Link, graphql } from "gatsby"

import Bio from "../components/bio"
import Layout from "../components/layout"
import SEO from "../components/seo"
import { rhythm } from "../utils/typography"
import Button from "../components/button"

class Blog extends React.Component {
  render() {
    const { data } = this.props
    const siteTitle = data.site.siteMetadata.title
    const posts = data.allMdx.edges

    return (
      <Layout location={this.props.location} title={siteTitle}>
        <SEO title="All posts" />
        <Bio />
        <div style={{ margin: "20px 0 40px" }}>
          {posts.map(({ node }) => {
            const title = node.frontmatter.title || node.fields.slug
            return (
              <div key={node.fields.slug}>
                <h3
                  style={{
                    marginBottom: rhythm(1 / 4),
                  }}
                >
                  <Link
                    style={{ boxShadow: `none` }}
                    to={`blog${node.fields.slug}`}
                  >
                    {title}
                  </Link>
                </h3>
                <small>{node.frontmatter.date}</small>
                <p
                  dangerouslySetInnerHTML={{
                    __html: node.frontmatter.description || node.excerpt,
                  }}
                />
              </div>
            )
          })}
        </div>
        <Link to="/">
          <Button marginTop="15px">Go Home</Button>
        </Link>
      </Layout>
    )
  }
}

export default Blog

export const pageQuery = graphql`
  query {
    site {
      siteMetadata {
        title
      }
    }
    allMdx(sort: { fields: [frontmatter___date], order: DESC }) {
      edges {
        node {
          excerpt
          fields {
            slug
          }
          frontmatter {
            date(formatString: "MMMM DD, YYYY")
            title
            description
          }
        }
      }
    }
  }
`