Gatsby Source Plugin

In this tutorial, you'll learn about Gatsby Source Plugin Error Fix. We cover key concepts, practical examples, and best practices.

The Problem

Error: "gatsby-source-filesystem" — the plugin is not configured.
No nodes created from the source plugin. Check your gatsby-config.js.

Gatsby source plugins need configuration to specify which data to fetch.

Wrong

// gatsby-config.js
module.exports = {
  plugins: ['gatsby-source-filesystem']
}

Output: no filesystem nodes created. The plugin runs but has no options telling it which directory to source.

Right

module.exports = {
  plugins: [
    {
      resolve: 'gatsby-source-filesystem',
      options: {
        name: 'posts',
        path: `${__dirname}/content/posts`,
      },
    },
  ],
}

Output: GraphQL nodes are created for all files in content/posts/.

Prevention

• Always provide options with path for gatsby-source-filesystem
• Use name to label different source instances
• Check GraphiQL at http://localhost:8000/___<a href="/apis/graphql/">Graphql</a> to verify nodes exist

Common Mistakes with source plugin

1. Mixing let bindings with <- bindings in do notation, producing type errors
2. Overlapping type class instances that cause GHC to reject the program with ambiguous dispatch errors
3. Non-exhaustive pattern matches that compile with warnings then crash at runtime

These mistakes appear frequently in real-world GATSBY code. DodaTech's contributors have identified these patterns through analysis of open-source projects and production systems.

Practice Exercise

Write a pure function that safely divides two integers using Maybe, then test it with edge cases like division by zero and negative numbers.

This exercise reinforces the concepts covered in this guide. Try implementing it before checking online solutions.

FAQ