EZ4: Factory

The Factory contract defines composable service factories for your application. It uses EZ4's reflection system to analyze your factory handler, variables, and connected services, then generates runtime bindings required to construct and combine service instances.

Getting started

Install

npm install @ez4/factory -D

Create a factory service

Factories are not infrastructure resources. Instead, they provide an organizational layer that other contracts can inject to create reusable, structured service objects.

// file: factory.ts
import type { Environment, Service } from '@ez4/common';
import type { Factory } from '@ez4/factory';

class MyService {
  public helloWorld() {}
}

// MyFactory declaration
export declare class MyFactory extends Factory.Service<MyService> {
  handler: typeof createMyService;

  variables: {
    myVariable: Environment.Variable<'MY_VARIABLE'>;
  };

  services: {
    otherService: Environment.Service<OtherService>;
    variables: Environment.ServiceVariables;
  };
}

Handle service creation

EZ4 injects all variables and services, then invokes your factory handler to construct the service instance.

// MyFactory handler
export function createMyService(context: Service.Context<MyFactory>): MyService {
  const { otherService, variables } = context;

  // Access injected services
  otherService.call();

  // Access injected variables
  variables.myVariable;

  // Return service instance
  return new MyService();
}

Use a factory

Any handler with access to the factory service can call the constructed service instance.

import type { Service } from '@ez4/common';
import type { MyFactory } from './factory';

// Any other handler that has injected MyFactory service
export async function anyHandler(_request: any, context: Service.Context<DummyService>) {
  const { myFactory } = context;

  // Call my service
  myFactory.helloWorld();
}

This makes it easy to centralize service creation and reuse logic across your application.

With your factory defined, EZ4 handles injection, construction, and service wiring automatically according to your contract.

Examples

• Schedule manager

License

MIT License