TypeScript Autogen

🚀 Lombok-style decorators for TypeScript — reduce boilerplate for getters, setters, builders, and related helpers. Works with both ESM and CommonJS modules.

✨ Features

• 🏗️ @Data – Generates getters, setters, toString, and equals
• 🔧 @Builder – Fluent builder pattern with type-safe method chaining
• 📝 @Getter / @Setter – Fine-grained property access control
• 🔍 @ToString / @Equals – Object string and equality helpers
• 🏭 @AllArgsConstructor / @NoArgsConstructor / @RequiredArgsConstructor – Flexible constructor generation
• 🔒 @Value – Immutable objects with readonly properties
• 🎯 TypeScript: opt-in typings for generated APIs via autogen / autogenDataBuilder (see below)
• 🔄 Automatic version checking to keep your decorators up-to-date

What was fixed

• autogen() typing – Previously autogen was typed to return any, so editors could not complete builder(), getters, setters, etc. You now pass a small feature map (with as const) that matches your decorators, or use autogenDataBuilder() for the common @Data() + @Builder() stack. Exported types include AutogenFeatures, AutogenClass, AugmentedInstance, and FluentBuilderFor.
• README accuracy – Decorators apply behavior at runtime (prototype / class wrapping), not via a separate compile-time code generator. Earlier wording implied zero runtime cost and compile-only transforms; that was incorrect.
• npm test on Windows – The test script no longer relies on Unix-style NODE_OPTIONS='...'; it uses node --import tsx so tests run on Windows and Unix.
• Stray markdown – Removed a duplicate closing fence in the Advanced Usage example.

1.1.0 ships the typed autogen / autogenDataBuilder APIs, README corrections, Windows-friendly npm test, and the related cleanup.

📦 Installation

npm install @bollo-aggrey/ts-autogen
yarn add @bollo-aggrey/ts-autogen
pnpm add @bollo-aggrey/ts-autogen

💡 The package includes automatic version checking to ensure you're always using the latest features and bug fixes. You'll be notified in your console if an update is available.

🚀 Quick Start

Basic Usage

import {
  Data,
  Builder,
  AllArgsConstructor,
  Getter,
  Setter,
  autogenDataBuilder
} from '@bollo-aggrey/ts-autogen';

@Data()
@Builder()
@AllArgsConstructor()
class ProductClass {
  @Getter() @Setter() name: string = '';
  @Getter() @Setter() price: number = 0;
  @Getter() @Setter() category: string = '';

  public save(): string {
    return `Saved product: ${this.name}`;
  }
}

export const Product = autogenDataBuilder(ProductClass);

const laptop = Product.builder()
  .name('MacBook Pro')
  .price(2499.99)
  .category('Electronics')
  .build();

console.log(laptop.getName());
console.log(laptop.toString());

Typing generated APIs (autogen)

TypeScript does not infer methods added by decorators. Use either:

• autogenDataBuilder(MyClass) when you use @Data() and @Builder() together (same typings as autogen(MyClass, { builder: true, data: true } as const)).
• autogen(MyClass, features as const) with flags that match your stack, for example { builder: true }, { data: true }, { instanceToString: true }, { instanceEquals: true } (the last two avoid clashing with Object.prototype.toString in the type map).

autogen(MyClass) with one argument still returns MyClass unchanged for typing: add the second argument when you want completions for generated members.

Advanced usage

import { Value, Builder, Getter, autogen } from '@bollo-aggrey/ts-autogen';

@Value()
@Builder()
class ImmutablePoint {
  @Getter() x: number = 0;
  @Getter() y: number = 0;

  distanceToOrigin(): number {
    return Math.sqrt(this.x * this.x + this.y * this.y);
  }
}

const Point = autogen(ImmutablePoint, {
  builder: true,
  instanceToString: true,
  instanceEquals: true
} as const);

const point = Point.builder().x(3).y(4).build();
console.log(point.distanceToOrigin());

📚 Complete Decorator Reference

@Getter and @Setter

Generate getter and setter methods for class properties.

class User {
  @Getter() private _name: string = '';
  @Setter() private _email: string = '';
}

const user = new User();
user.setEmail('[email protected]');
console.log(user.getEmail());

@ToString

Generates a toString() method.

@ToString()
class Point {
  x: number = 0;
  y: number = 0;
}

const point = new Point();
console.log(point.toString());

@Equals

Generates an equals() method (value objects often pair this with @ToString() or use @Value() which applies both).

@Equals()
class User {
  id: number = 0;
  name: string = '';
}

const user1 = new User();
user1.id = 1;
user1.name = 'Alice';

const user2 = new User();
user2.id = 1;
user2.name = 'Alice';

console.log(user1.equals(user2));

@RequiredArgsConstructor

Generates a constructor with required properties.

@RequiredArgsConstructor()
class User {
  @Getter() private readonly id: number;
  @Getter() private readonly name: string;
  private readonly optional?: string;
}

const user = new User(1, 'Alice');

@Data()

Combines @Getter, @Setter, @ToString, and @Equals.

import { Data, Getter, Setter, autogen } from '@bollo-aggrey/ts-autogen';

@Data()
class User {
  @Getter() @Setter() name: string = '';
  @Getter() @Setter() email: string = '';
}

const UserModel = autogen(User, { data: true } as const);

@Builder()

Generates a fluent builder.

import { Builder, Getter, autogen } from '@bollo-aggrey/ts-autogen';

@Builder()
class Config {
  @Getter() host: string = '';
  @Getter() port: number = 0;
}

const ConfigModel = autogen(Config, { builder: true } as const);
const config = ConfigModel.builder().host('localhost').port(3000).build();

@AllArgsConstructor() / @NoArgsConstructor()

import { AllArgsConstructor, NoArgsConstructor, Getter, Builder, autogen } from '@bollo-aggrey/ts-autogen';

@AllArgsConstructor()
@NoArgsConstructor()
class Point {
  @Getter() x: number = 0;
  @Getter() y: number = 0;
}

const PointModel = autogen(Point, { builder: true } as const);
const point1 = new PointModel(10, 20);
const point2 = new PointModel();

⚙️ Configuration

TypeScript Configuration

Add to your tsconfig.json:

{
  "compilerOptions": {
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true,
    "target": "ES2020",
    "module": "ESNext"
  }
}

Version Checking

The package includes an automatic version checker that runs on postinstall. To disable it, set the environment variable:

export TS_AUTOGEN_SKIP_VERSION_CHECK=true

Or check for updates manually:

npx ts-autogen-check --check-updates

🎯 Why Use TypeScript Autogen?

• ✅ Reduced Boilerplate - Generate common methods automatically
• ✅ Type safety - Strong typings when you use autogen / autogenDataBuilder with a matching feature map
• ✅ Familiar API - Similar to Java Lombok for easy adoption
• ✅ Runtime decorators - Generated members are attached when the class is defined (no separate build plugin required)
• ✅ Immutability Support - First-class support for immutable data structures
• ✅ Framework Agnostic - Works with any TypeScript project
• ✅ Automatic Updates - Built-in version checking to keep you up-to-date

📋 Requirements

• Node.js 20.0+
• TypeScript 4.5+
• "experimentalDecorators": true in tsconfig.json
• "emitDecoratorMetadata": true in tsconfig.json (required for some features)

🧪 Testing

npm test

🤝 Contributing

Contributions welcome! Open issues and PRs are appreciated.

📄 License

MIT License – see LICENSE

🙏 Acknowledgments

• Inspired by Project Lombok for Java
• Made with ❤️ for the TypeScript community