@fioc/strict

@fioc/strict is an extension of FIoC (Fluid Inversion Of Control) providing stricter type checking and compile-time validation for dependency injection in TypeScript/JavaScript applications. It enhances @fioc/core by enforcing safety rules to prevent runtime errors and type mismatches.

🔑 Key Advantages

• 🔒 Compile-time validation: Detect unregistered dependencies or duplicate tokens at compile time.
• 🛡️ Safe resolution: Resolving unregistered dependencies returns type never.
• 🚀 Strict factory validation: Ensure factory parameters match registered dependencies.
• 🧩 Composable containers: Merge strict containers while preserving type safety.
• 🛠️ Controlled replacements: Safely replace existing registrations with replace or replaceFactory.

Unlike @fioc/core, @fioc/strict focuses solely on compile-time guarantees and validation.

Installation

npm install @fioc/core @fioc/strict
# or
yarn add @fioc/core @fioc/strict
# or
pnpm add @fioc/core @fioc/strict

Quick Example: Strict Registration & Resolving

import { buildStrictDIContainer } from "@fioc/strict";
import { createDIToken } from "@fioc/core";

interface ApiService {
  getData: () => string;
}

const ApiServiceToken = createDIToken<ApiService>().as("ApiService");

const HttpApiService: ApiService = { getData: () => "Hello, World!" };

const container = buildStrictDIContainer()
  .register(ApiServiceToken, HttpApiService)
  .getResult();

const apiService = container.resolve(ApiServiceToken); // Type `never` if not registered
apiService.getData(); // "Hello, World!"

Advanced Usage

Factories with Strict Validation

import { buildStrictDIContainer } from "@fioc/strict";
import { createDIToken } from "@fioc/core";

export const getDataUseCaseToken =
  createDIToken<() => string>().as("getDataUseCase");

const getDataUseCaseFactory = (apiService: ApiService) => () =>
  apiService.getData();

const container = buildStrictDIContainer()
  .register(ApiServiceToken, HttpApiService)
  .registerFactory(getDataUseCaseToken, {
    // Type error if the token is already registered
    dependencies: [ApiServiceToken], // Type error if not registered
    factory: getDataUseCaseFactory,
  })
  .getResult();

const useCase = container.resolve(getDataUseCaseToken); // Type `never` if not registered
useCase();

Replacing Registrations Safely

const newImplementation: ApiService = { getData: () => "New Data!" };

const container = buildStrictDIContainer()
  .register(ApiServiceToken, HttpApiService)
  .replace(ApiServiceToken, newImplementation) // Won't give type error
  .replaceFactory(getDataUseCaseToken, {
    dependencies: [ApiServiceToken],
    factory: getDataUseCaseFactory,
  })
  .getResult();

Contributing

Open issues or submit pull requests on GitHub. Include tests for behavioral changes.

License

MIT License. See LICENSE.