Elixir Document Nodes Plugin

A GraphQL Code Generator plugin that generates Elixir modules with embedded GraphQL document nodes. This plugin helps you integrate GraphQL operations seamlessly into your Elixir codebase.

This plugin is a fork of GraphQL Code Generator with added support for Elixir document nodes generation. The original project is maintained by The Guild and has support for multiple languages and frameworks.

Installation

You can install the plugin using npm, yarn, or pnpm:

# npm
npm install --save-dev elixir-document-nodes

# yarn
yarn add -D elixir-document-nodes

# pnpm
pnpm add -D elixir-document-nodes

Requirements

• Node.js >= 16
• GraphQL >= 14.0.0
• A running GraphQL server (for schema introspection)
• Elixir/Mix (for formatting generated files)

Usage

Basic Setup

Create a codegen.ts configuration file in your project root:

import type { CodegenConfig } from "@graphql-codegen/cli";

const config: CodegenConfig = {
  schema: "schema.graphql",
  documents: "graphql/**/*.graphql",
  generates: {
    "./lib/generated/graphql.ex": {
      plugins: ["elixir-document-nodes"],
    },
  },
};

export default config;

Advanced Configuration

Here's a more comprehensive example with all available options:

import type { CodegenConfig } from "@graphql-codegen/cli";
import { execSync } from "child_process";

const config: CodegenConfig = {
  overwrite: true,
  schema: "http://localhost:4000/graphql", // Your GraphQL schema endpoint
  documents: "graphql/**/*.graphql", // Path to your GraphQL operations
  generates: {
    // Generate schema for reference
    "./schema.graphql": {
      plugins: ["schema-ast"],
    },
    // Generate Elixir modules
    "./lib/generated/graphql.ex": {
      plugins: ["elixir-document-nodes"],
      config: {
        // Convert GraphQL names to snake_case (Elixir convention)
        namingConvention: "change-case-all#snakeCase",
        // Your target Elixir module name
        moduleName: "MyApp.GraphQL.Documents",
        // Add more configuration options here
      },
      // Format the generated Elixir code using mix format
      hooks: {
        afterOneFileWrite: (filePath) => {
          try {
            execSync(`mix format ${filePath}`);
            console.log(`✨ Formatted ${filePath}`);
          } catch (error) {
            console.error(`Error formatting file: ${error}`);
          }
        },
      },
    },
  },
};

export default config;

Configuration Options

| Option | Type | Default | Description | | ------------------ | ----------- | ----------------------------- | ----------------------------------------------- | | moduleName | string | "GraphQL.Documents" | The name of the generated Elixir module | | namingConvention | string | "change-case-all#snakeCase" | The naming convention for generated identifiers | | scalars | ScalarMap | {} | Custom scalar type mappings |

Example Output

For a GraphQL query like:

query GetUser($id: ID!) {
  user(id: $id) {
    id
    name
    email
  }
}

The plugin generates an Elixir module like:

defmodule MyApp.GraphQL.Documents do
  @moduledoc """
  Generated GraphQL document nodes.
  """

  def get_user do
    """
    query GetUser($id: ID!) {
      user(id: $id) {
        id
        name
        email
      }
    }
    """
  end
end

Running Code Generation

# Using npx
npx graphql-codegen

# Or if you have it in your package.json scripts
npm run codegen

License

MIT License - see LICENSE file for details.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Issues

If you find a bug or have a feature request, please create an issue in the GitHub repository.