@favy/di

Why?

Imagine being able to substitute any function in an application? This will make it easy to test any part of the application. Low coupling will make it easy to change the structure of the application.

Problem

All existing di for typescript are too complicated and make you write a lot of code. Almost nobody uses them.

Features

• 🚀 Create modules as easily as functions
• 🔧 Easily replace any dependency at any level
• 🌟 Simple integration into any project
• 💪 Full TypeScript support with type inference
• 🧩 High extensibility and support for Higher Kinded Types
• 🎯 Caching and lazy initialization

Why @favy/di?

Unlike many other solutions, @favy/di offers:

• Minimal syntax: No need for decorators or complex configurations.
• Easy integration: A module is just a function, so it can be integrated anywhere.
• Performance: Minimal runtime overhead.
• Flexibility: Easily adapts to different programming styles and patterns.

Installation

npm install @favy/di

Quick Start

import { Module, type Live } from '@favy/di';

const SimpleModule = Module()('SimpleModule', () => 'Hello, DI!');
console.log(SimpleModule()); // Output: Hello, DI!

// Simple module combination
const ModuleA = Module()('ModuleA', () => 10);
type ALive = Live<typeof ModuleA>;

const ModuleB = Module()('ModuleB', () => 5);
type BLive = Live<typeof ModuleB>;

const CombinedModule = Module<ALive & BLive>()('CombinedModule', ($) => $.ModuleA + $.ModuleB);
console.log(CombinedModule({ ModuleA, ModuleB })); // Output: 15

Advanced Usage

Partial Application with .provide()

const CalculatorModule = Module<{ x: number, y: number }>()('Calculator', ({ x, y }) => x + y);
const PartialCalculator = CalculatorModule.provide({ x: 5 });
console.log(PartialCalculator({ y: 3 })); // Output: 8

Lazy Initialization

import { Module, type Live } from '@favy/di';

const LazyModule = Module()('LazyModule', () => {
  console.log('LazyModule initialized');
  return 42;
});
type LazyModuleLive = Live<typeof LazyModule>;

const Consumer = Module<LazyModuleLive>()('Consumer', ($) => {
  setTimeout(() => $.LazyModule, 1000);
});

Consumer({ LazyModule }); 
// Prints "LazyModule initialized" after 1 second

Cache Management

const Module = makeModule({
  cache: 'module' 
});

const CachedModule = Module()('CachedModule', () => Math.random());
console.log(CachedModule()); // Random number
console.log(CachedModule()); // Same number

Module.flushCache(); // Clear cache
console.log(CachedModule()); // New random number

Documentation

For more detailed information about the library's capabilities and usage examples, please refer to our full documentation.

Contributing

We welcome community contributions! If you have suggestions for improvements or have found a bug, please create an issue or submit a pull request.

License

@favy/di is distributed under the MIT license. See the LICENSE file for more information.