​
Overview

Amplication plugins are built using Webpack, which bundles all dependencies into the dist folder. This ensures that plugins can run independently without requiring external dependencies at runtime. However, when developing multiple plugins that share common utilities or logic, duplicating code is inefficient. Instead, you can create a shared library that can be locally imported into your plugins using the method described below. This guide explains how to create a shared library and integrate it into Amplication plugins using npm dependencies and Webpack configuration.

​
Creating the Shared Library

  1. Create a new folder for the shared library
    • Inside your plugin repository, create a new directory under root called lib.
  2. Initialize an npm package
    • Navigate to lib and create a new package: 
      cd lib
mkdir shared
cd shared
npm init -y
    • This creates a package.json file with the package name shared.
  3. Add utility functions
    • Inside the shared directory, create an index.ts file and add a utility function: 
      export const toCamelCase = (str: string): string => {
  return str.replace(/([-_][a-z])/g, (group) => group.toUpperCase().replace('-', '').replace('_', ''));
};

​
Using the Shared Library in a Plugin

  1. Add the shared library as a dependency
    • Inside the package.json of the target plugin, add a local dependency: 
      "dependencies": {
  "@my-org/shared": "file:../../lib/shared"
}
    • Replace @my-org with your package scope if needed.
  2. Update Webpack Configuration
    • Open webpack.config.js in your plugin directory and add an alias for the shared package: 
      const path = require('path');

module.exports = {
  resolve: {
    alias: {
      '@my-org/shared': path.resolve(__dirname, '../../lib/shared')
    }
  }
};
  3. Import and Use the Shared Library
    • Inside your plugin, import and use the shared utility function: 
      import { toCamelCase } from '@my-org/shared';

const testString = "my test string";
const result = toCamelCase(testString);
context.logger.info(`Shared utility function result: ${result}`);

​
Running and Testing

  1. Install dependencies and build the shared package: 
    cd lib/shared
npm install
npm run build
  2. Install dependencies in your plugin and run it: 
    cd ../plugins/my-plugin
npm install
npm run build
  3. Execute the plugin to verify that the shared function is correctly used.

​
Conclusion

Using a shared library in Amplication plugins allows you to centralize reusable utilities, improving maintainability and consistency across multiple plugins. By setting up local dependencies and Webpack aliases, you can seamlessly integrate shared functions into your development workflow.