226 lines
5.7 KiB
Markdown
226 lines
5.7 KiB
Markdown
# netdi
|
|
|
|
[](https://github.com/StevanFreeborn/netdi/actions/workflows/pull_request.yml)
|
|
[](https://codecov.io/gh/StevanFreeborn/netdi)
|
|
[](https://github.com/StevanFreeborn/netdi/actions/workflows/publish.yml)
|
|
[](https://github.com/semantic-release/semantic-release)
|
|
|
|
|
|
|
|
|
|
A dependency injection container for [TypeScript](https://www.typescriptlang.org/) projects that is inspired by the [.NET](https://dotnet.microsoft.com/en-us/) DI container. It is designed to be simple, lightweight, and easy to use.
|
|
|
|
## Features
|
|
|
|
- ✅ .NET-style service registration with different lifetimes (singleton, scoped, transient)
|
|
- ✅ Constructor injection with decorators
|
|
- ✅ Type-safe dependency resolution
|
|
- ✅ Factory method support for complex instantiation scenarios
|
|
- ✅ Scoped service lifetimes for per-request contexts
|
|
|
|
## Installation
|
|
|
|
```bash
|
|
# npm
|
|
npm install @stevanfreeborn/netdi
|
|
|
|
# yarn
|
|
yarn add @stevanfreeborn/netdi
|
|
|
|
# pnpm
|
|
pnpm add @stevanfreeborn/netdi
|
|
```
|
|
|
|
## Requirements
|
|
|
|
- Node.js >= 18.0.0
|
|
- TypeScript with decorators and reflection metadata enabled
|
|
|
|
Add the following to your `tsconfig.json`:
|
|
|
|
```json
|
|
{
|
|
"compilerOptions": {
|
|
"experimentalDecorators": true,
|
|
"emitDecoratorMetadata": true
|
|
}
|
|
}
|
|
```
|
|
|
|
## Basic Usage
|
|
|
|
Here's a simple example of how to use netdi:
|
|
|
|
```typescript
|
|
import {
|
|
ServiceCollection,
|
|
createServiceIdentifier,
|
|
injectable,
|
|
inject,
|
|
} from '@stevanfreeborn/netdi';
|
|
|
|
// Define interfaces
|
|
interface IGreeter {
|
|
greet(name: string): string;
|
|
}
|
|
|
|
interface IGreetingService {
|
|
createGreeting(name: string): string;
|
|
}
|
|
|
|
// Create service identifiers
|
|
const greeterIdentifier = createServiceIdentifier<IGreeter>();
|
|
const greetingServiceIdentifier = createServiceIdentifier<IGreetingService>();
|
|
|
|
// Implement services
|
|
@injectable()
|
|
class GreetingService implements IGreetingService {
|
|
createGreeting(name: string): string {
|
|
return `Hello, ${name}!`;
|
|
}
|
|
}
|
|
|
|
@injectable()
|
|
class Greeter implements IGreeter {
|
|
constructor(@inject(greetingServiceIdentifier) private greetingService: IGreetingService) {}
|
|
|
|
greet(name: string): string {
|
|
return this.greetingService.createGreeting(name);
|
|
}
|
|
}
|
|
|
|
// Set up dependency injection
|
|
const services = new ServiceCollection();
|
|
|
|
// Register services
|
|
services.addSingleton(greetingServiceIdentifier, GreetingService);
|
|
services.addScoped(greeterIdentifier, Greeter);
|
|
|
|
// Build service provider
|
|
const serviceProvider = services.build();
|
|
|
|
// Resolve and use a service
|
|
const greeter = serviceProvider.getService(greeterIdentifier);
|
|
console.log(greeter.greet('World')); // Outputs: Hello, World!
|
|
```
|
|
|
|
## Service Lifetimes
|
|
|
|
netdi supports three service lifetimes:
|
|
|
|
### Singleton
|
|
|
|
Singleton services are created once and shared by all consumers.
|
|
|
|
```typescript
|
|
services.addSingleton(serviceIdentifier, Implementation);
|
|
```
|
|
|
|
### Scoped
|
|
|
|
Scoped services are created once per scope. This is useful for services that should be shared within a request but not across requests.
|
|
|
|
```typescript
|
|
services.addScoped(serviceIdentifier, Implementation);
|
|
|
|
// Create a scope
|
|
const scope = serviceProvider.createScope();
|
|
const scopedService = scope.serviceProvider.getService(serviceIdentifier);
|
|
|
|
// When done with the scope
|
|
scope.dispose();
|
|
```
|
|
|
|
### Transient
|
|
|
|
Transient services are created each time they are requested.
|
|
|
|
```typescript
|
|
services.addTransient(serviceIdentifier, Implementation);
|
|
```
|
|
|
|
## Factory Registration
|
|
|
|
For complex service instantiation, you can use factory methods:
|
|
|
|
```typescript
|
|
services.addSingleton(serviceIdentifier, provider => {
|
|
// Use the provider to get dependencies
|
|
const dependency = provider.getService(dependencyIdentifier);
|
|
|
|
// Create and configure your service instance
|
|
const instance = new MyService(dependency);
|
|
instance.configure();
|
|
|
|
return instance;
|
|
});
|
|
```
|
|
|
|
## Creating Service Identifiers
|
|
|
|
Service identifiers help maintain type safety and prevent service conflicts:
|
|
|
|
```typescript
|
|
// Create an identifier for a specific interface
|
|
const userServiceIdentifier = createServiceIdentifier<IUserService>();
|
|
|
|
// Then use it for registration and resolution
|
|
services.addSingleton(userServiceIdentifier, UserService);
|
|
const userService = serviceProvider.getService(userServiceIdentifier);
|
|
```
|
|
|
|
## Decorators
|
|
|
|
### @injectable()
|
|
|
|
Marks a class as injectable, allowing the container to create instances with dependencies:
|
|
|
|
```typescript
|
|
@injectable()
|
|
class MyService {
|
|
constructor() {}
|
|
}
|
|
```
|
|
|
|
### @inject()
|
|
|
|
Specifies a dependency for a parameter:
|
|
|
|
```typescript
|
|
class MyService {
|
|
constructor(
|
|
@inject(loggerIdentifier) private logger: ILogger,
|
|
@inject(configIdentifier) private config: IConfig,
|
|
) {}
|
|
}
|
|
```
|
|
|
|
## Advanced Topics
|
|
|
|
### Service Disposal
|
|
|
|
Both service providers and scopes implement a `dispose()` method:
|
|
|
|
```typescript
|
|
// Dispose the root provider
|
|
serviceProvider.dispose();
|
|
|
|
// Dispose a scope
|
|
const scope = serviceProvider.createScope();
|
|
// ... use scope
|
|
scope.dispose();
|
|
```
|
|
|
|
### Type Safety
|
|
|
|
netdi is designed to be fully type-safe. The `getService()` method returns the exact type associated with the service identifier:
|
|
|
|
```typescript
|
|
// TypeScript knows this is an IUserService
|
|
const userService = serviceProvider.getService(userServiceIdentifier);
|
|
```
|
|
|
|
## License
|
|
|
|
MIT © [Stevan Freeborn](https://github.com/StevanFreeborn)
|