Creating node.js plugins

Node.js plugins are installed as npm packages. To create a plugin, you need to create a new npm package. This can be done with the npm init command.

npm init

This will create a new npm package. You can then add the @datagen-rs/types package as a dependency, if desired, as this package provides typescript types for the plugin API.

npm install --save-dev @datagen-rs/types

You can then create a new file, for example index.ts, and start writing your plugin. A plugin must export a function with the following signature:

export type PluginInitFunction = (
  args: any
) => DatagenPlugin | Promise<DatagenPlugin>;

The args parameter is an object containing the arguments passed to the plugin in the configuration file. The DatagenPlugin type is defined in the @datagen-rs/types package and looks like this:

interface DatagenPlugin {
  generate?(schema: CurrentSchema, args: any): any | Promise<any>;
  transform?(schema: CurrentSchema, args: any, value: any): any | Promise<any>;
  serialize?(args: any, value: any): string | Promise<string>;
}

All methods are optional. The generate method is called when a new value is generated. The transform method is called when a value is transformed. The serialize method is called when a value is serialized to a string.

Example

You may want to implement your plugin as follows:

import { DatagenPlugin, CurrentSchema } from '@datagen-rs/types';
 
class MyPlugin implements DatagenPlugin {
  constructor(args: any) {
    // Initialize the plugin
  }
 
  generate(schema: CurrentSchema, args: any): any {
    // Generate a new value
  }
 
  transform(schema: CurrentSchema, args: any, value: any): any {
    // Transform a value
  }
 
  serialize(args: any, value: any): string {
    // Serialize a value
  }
}
 
export default function pluginConstructor(args: any): DatagenPlugin {
  return new MyPlugin(args);
}