@syncafricabs/kernspark-elysiajs

ElysiaJS adapter for the SyncAfrica KernSpark ecosystem. This package provides production-ready ElysiaJS plugins, error handlers, and response utilities that integrate the framework-independent @syncafricabs/kernspark-core with ElysiaJS.

Table of Contents

• What is it?
• Why it exists
• Features
• Installation
• Quick Start
• Comprehensive Usage
  • Plugin Registration
  • Error Handling
  • Response Adapter
  • Route Handlers
• API Reference
• Error Handling Reference
• TypeScript Support
• Compatibility Matrix
• Contributing
• License
• Author

What is it?

@syncafricabs/kernspark-elysiajs is a framework adapter that bridges the SyncAfrica KernSpark Core with ElysiaJS. It provides:

• ElysiaJsIntegration - Maps ApplicationError instances to standardized JSON API responses
• ElysiaJsResponseAdapter - Helper methods for sending consistent success and error responses
• elysiaJsPlugin - Elysia plugin with correlation ID and error handling
• withElysiaErrorHandling - Higher-order function for wrapping route handlers with error handling

The adapter follows the adapter pattern: it depends on @syncafricabs/kernspark-core (the framework-independent layer) and ElysiaJS only in the adapter layer. The core has zero framework dependencies.

Why it exists

Modern web applications benefit from a KernSpark - a common set of contracts, types, and behaviors shared across bounded contexts. The SyncAfrica KernSpark provides:

1. Standardized API envelopes (ApiSuccess / ApiError)
2. Rich domain error hierarchy (ValidationError, BusinessError, AuthenticationError, etc.)
3. Result types (Result, Ok, Err)
4. Domain primitives (UUID, Money, Entity, ValueObject)

Without adapters, each team would reimplement framework-specific plumbing to use these core types. This adapter eliminates that duplication by providing ElysiaJS-specific bindings.

Features

• Plugin registration - Drop-in Elysia plugin with error handling
• Standardized JSON responses - All responses follow the ApiSuccess / ApiError envelope
• Zero-configuration error handling - Wraps route handlers automatically
• Full TypeScript support - Comprehensive type definitions included
• Production-ready - Proper error handling, stack traces, cause chains
• Framework isolation - Core has no ElysiaJS dependencies

Installation

npm install @syncafricabs/kernspark-elysiajs @syncafricabs/kernspark-core elysia

Or with your preferred package manager:

yarn add @syncafricabs/kernspark-elysiajs @syncafricabs/kernspark-core elysia

pnpm add @syncafricabs/kernspark-elysiajs @syncafricabs/kernspark-core elysia

Quick Start

import { Elysia } from 'elysia';
import { elysiaJsPlugin, withElysiaErrorHandling, ElysiaJsResponseAdapter } from '@syncafricabs/kernspark-elysiajs';
import { NotFoundError, ValidationError } from '@syncafricabs/kernspark-core';

const app = new Elysia()
  .use(elysiaJsPlugin({
    logErrors: true,
    includeCause: true,
  }))
  .get('/users/:id', withElysiaErrorHandling(async ({ params }) => {
    const user = findUser(params.id);

    if (!user) {
      throw new NotFoundError('User not found');
    }

    return ElysiaJsResponseAdapter.ok({ status: 200, success: true, data: user, message: 'OK' });
  }))
  .post('/users', withElysiaErrorHandling(async ({ body }) => {
    if (!body.name || !body.email) {
      throw new ValidationError('MISSING_FIELDS', 'Name and email are required');
    }

    const user = createUser(body);
    return ElysiaJsResponseAdapter.created({ status: 201, success: true, data: user, message: 'Created' });
  }))
  .listen(3000);

Comprehensive Usage

Plugin Registration

Basic Plugin

import { Elysia } from 'elysia';
import { elysiaJsPlugin } from '@syncafricabs/kernspark-elysiajs';

const app = new Elysia()
  .use(elysiaJsPlugin())
  .get('/', () => 'Hello World')
  .listen(3000);

Plugin with Options

import { Elysia } from 'elysia';
import { elysiaJsPlugin, ElysiaJsPluginOptions } from '@syncafricabs/kernspark-elysiajs';

const options: ElysiaJsPluginOptions = {
  logErrors: true,
  logStack: process.env.NODE_ENV === 'development',
  includeCause: true,
  includeStack: false,
  defaultStatusCode: 500,
  logger: (error, context) => {
    console.error({
      method: context.method,
      path: context.path,
      error: error.message,
      stack: error.stack,
    });
  },
};

const app = new Elysia()
  .use(elysiaJsPlugin(options))
  .get('/', () => 'Hello World')
  .listen(3000);

Error Handling

Throwing Errors from Route Handlers

import { withElysiaErrorHandling, ElysiaJsResponseAdapter } from '@syncafricabs/kernspark-elysiajs';
import {
  ValidationError,
  MissingFieldsError,
  BusinessError,
  ConflictError,
  NotFoundError,
  AuthenticationError,
  InvalidTokenError,
  AuthorizationError,
  PermissionDeniedError,
  InfrastructureError,
  ExternalServiceError,
} from '@syncafricabs/kernspark-core';

const app = new Elysia()
  .get('/users/:id', withElysiaErrorHandling(async ({ params }) => {
    const user = findUser(params.id);
    if (!user) {
      throw new NotFoundError('User not found');
    }
    return { user, message: 'User retrieved' };
  }))
  .post('/users', withElysiaErrorHandling(async ({ body }) => {
    if (!body.name || !body.email) {
      throw new MissingFieldsError('Name and email are required');
    }
    const user = createUser(body);
    return { user, message: 'User created' };
  }))
  .delete('/users/:id', withElysiaErrorHandling(async ({ params, headers }) => {
    const token = headers.authorization;
    if (!token || !isValidToken(token)) {
      throw new InvalidTokenError('Invalid or expired token');
    }
    deleteUser(params.id);
    return { message: 'User deleted' };
  }));

Response Adapter

Success Responses

import { ElysiaJsResponseAdapter } from '@syncafricabs/kernspark-elysiajs';

// 200 OK with data
return ElysiaJsResponseAdapter.ok(user, 'User retrieved');

// 201 Created with data
return ElysiaJsResponseAdapter.created(user, 'User created');

// 204 No Content
return ElysiaJsResponseAdapter.noContent();

Error Responses

import { ElysiaJsResponseAdapter } from '@syncafricabs/kernspark-elysiajs';

return ElysiaJsResponseAdapter.badRequest('MISSING_FIELDS', 'Email and password are required');
return ElysiaJsResponseAdapter.unauthorized('INVALID_CREDENTIALS', 'Invalid email or password');
return ElysiaJsResponseAdapter.forbidden('PERMISSION_DENIED', 'You do not have permission');
return ElysiaJsResponseAdapter.notFound('NOT_FOUND', 'User not found');
return ElysiaJsResponseAdapter.conflict('CONFLICT', 'Resource already exists');
return ElysiaJsResponseAdapter.unprocessableEntity('INVALID_DATA', 'Invalid request data');
return ElysiaJsResponseAdapter.tooManyRequests('RATE_LIMIT_EXCEEDED', 'Too many requests');
return ElysiaJsResponseAdapter.internalServerError('INTERNAL_ERROR', 'An unexpected error occurred');
return ElysiaJsResponseAdapter.badGateway('BAD_GATEWAY', 'Upstream service error');
return ElysiaJsResponseAdapter.serviceUnavailable('SERVICE_UNAVAILABLE', 'Service temporarily unavailable');
return ElysiaJsResponseAdapter.gatewayTimeout('GATEWAY_TIMEOUT', 'Upstream service timeout');

Route Handlers

GET with Validation

import { withElysiaErrorHandling, ElysiaJsResponseAdapter } from '@syncafricabs/kernspark-elysiajs';
import { NotFoundError, ValidationError } from '@syncafricabs/kernspark-core';

const app = new Elysia()
  .get('/users/:id', withElysiaErrorHandling(async ({ params }) => {
    const user = findUser(params.id);

    if (!user) {
      throw new NotFoundError('User not found');
    }

    return ElysiaJsResponseAdapter.ok({ status: 200, success: true, data: user, message: 'OK' });
  }));

POST with Business Rules

import { withElysiaErrorHandling, ElysiaJsResponseAdapter } from '@syncafricabs/kernspark-elysiajs';
import { ValidationError, ConflictError, BusinessError } from '@syncafricabs/kernspark-core';

const app = new Elysia()
  .post('/users', withElysiaErrorHandling(async ({ body }) => {
    if (!body.name || !body.email) {
      throw new ValidationError('MISSING_FIELDS', 'Name and email are required');
    }

    const existingUser = findUserByEmail(body.email);
    if (existingUser) {
      throw new ConflictError('User with this email already exists');
    }

    if (body.balance < 0) {
      throw new BusinessError('INVALID_BALANCE', 400, 'Balance cannot be negative');
    }

    const user = createUser(body);
    return ElysiaJsResponseAdapter.created({ status: 201, success: true, data: user, message: 'Created' });
  }));

API Reference

elysiaJsErrorHandler

ElysiaJS error handling handler. Catches all errors and maps them to standardized JSON responses.

function elysiaJsErrorHandler(error: Error, context: { method: string; path: string }): Response;

createElysiaJsErrorHandler(options?: ElysiaJsErrorHandlerOptions)

Creates a customized error handler.

| Option | Type | Default | Description | |--------|------|---------|-------------| | logErrors | boolean | true | Enable/disable error logging | | logStack | boolean | false | Include stack traces in logs | | includeCause | boolean | true | Include error cause in response | | includeStack | boolean | false | Include stack traces in response (dev only) | | defaultStatusCode | number | 500 | Default status for unknown errors | | logger | function | console.error | Custom logger function |

ElysiaJsResponseAdapter

Static utility class for sending responses.

| Method | HTTP Status | Description | |--------|-------------|-------------| | sendSuccess(response, apiSuccess) | varies | Send raw ApiSuccess | | sendError(response, apiError) | varies | Send raw ApiError | | ok(data?, message?) | 200 | Send success response with data | | created(data?, message?) | 201 | Send created response with data | | noContent(message?) | 204 | Send no content response | | badRequest(errorCode, message) | 400 | Send bad request error | | unauthorized(errorCode, message) | 401 | Send unauthorized error | | forbidden(errorCode, message) | 403 | Send forbidden error | | notFound(errorCode, message) | 404 | Send not found error | | conflict(errorCode, message) | 409 | Send conflict error | | unprocessableEntity(errorCode, message) | 422 | Send unprocessable entity error | | tooManyRequests(errorCode, message) | 429 | Send too many requests error | | internalServerError(errorCode, message) | 500 | Send internal server error | | badGateway(errorCode, message) | 502 | Send bad gateway error | | serviceUnavailable(errorCode, message) | 503 | Send service unavailable error | | gatewayTimeout(errorCode, message) | 504 | Send gateway timeout error |

elysiaJsPlugin(options?: ElysiaJsPluginOptions)

Creates an Elysia plugin with error handling and correlation ID support.

function elysiaJsPlugin(options?: ElysiaJsPluginOptions): Elysia;

withElysiaErrorHandling(handler, options?)

Wraps an Elysia route handler with error handling.

function withElysiaErrorHandling<T extends ElysiaJsRouteHandler>(
  handler: T,
  options?: ElysiaJsErrorHandlerOptions
): ElysiaJsRouteHandler;

Error Handling Reference

The error handler maps the following ApplicationError subclasses:

| Error Class | HTTP Status | Error Code | |-------------|-------------|------------| | ValidationError | 400 | Custom (e.g., INVALID, MISSING_FIELDS) | | MissingFieldsError | 400 | MISSING_FIELDS | | BusinessError | Varies | Custom | | ConflictError | 409 | CONFLICT | | InsufficientFundsError | 400 | INSUFFICIENT_FUNDS | | QuotaExceededError | 429 | QUOTA_EXCEEDED | | NotFoundError | 404 | NOT_FOUND | | ExpiredError | 410 | EXPIRED | | TooManyRequestsError | 429 | TOO_MANY_REQUESTS | | PaymentRequiredError | 402 | PAYMENT_REQUIRED | | LockedError | 423 | LOCKED | | AccountSuspendedError | 403 | ACCOUNT_SUSPENDED | | FeatureNotAvailableError | 501 | FEATURE_NOT_AVAILABLE | | DataIntegrityError | 422 | DATA_INTEGRITY_ERROR | | AuthenticationError | 401 | Custom (e.g., INVALID_TOKEN) | | InvalidTokenError | 401 | INVALID_TOKEN | | TokenExpiredError | 401 | TOKEN_EXPIRED | | SessionExpiredError | 401 | SESSION_EXPIRED | | AuthorizationError | Varies | Custom | | PermissionDeniedError | 403 | PERMISSION_DENIED | | NotAllowedError | 403 | NOT_ALLOWED | | InfrastructureError | Varies | Custom | | ExternalServiceError | 502 | EXTERNAL_SERVICE_ERROR | | BadGatewayError | 502 | BAD_GATEWAY | | GatewayTimeoutError | 504 | GATEWAY_TIMEOUT | | ServiceUnavailableError | 503 | SERVICE_UNAVAILABLE | | RequestFailedError | 500 | REQUEST_FAILED | | NotImplementedError | 501 | NOT_IMPLEMENTED | | MaintenanceModeError | 503 | MAINTENANCE_MODE |

Unknown ApplicationError instances use their embedded statusCode. Non-ApplicationError errors return HTTP 500 with INTERNAL_SERVER_ERROR code.

TypeScript Support

Full TypeScript support with strict mode enabled. The adapter extends ElysiaJS types:

import { Elysia } from 'elysia';

// Route handler type augmentation
interface RouteHandlerContext {
  body: any;
  params: Record<string, string>;
  headers: Headers;
  request: Request;
  set: {
    headers: Headers;
    status: number;
  };
}

Strict Mode

This package is compiled with strict: true. Enable strict mode in your project for full type safety:

{
  "compilerOptions": {
    "strict": true,
    "noImplicitAny": true,
    "strictNullChecks": true
  }
}

Compatibility Matrix

| Package Version | Node.js | ElysiaJS | @syncafricabs/kernspark-core | |----------------|---------|----------|----------------------------------| | 1.0.0 | >=18.0.0 | ^0.7.0 | ^1.0.0 |

| Feature | ElysiaJS 0.7+ | |---------|---------------| | Plugin system | Supported | | Error handling | Supported | | Route handlers | Supported | | TypeScript 5.0+ | Supported |

Contributing

1. Fork the repository
2. Create your feature branch: git checkout -b feature/my-feature
3. Commit your changes: git commit -am 'Add my feature'
4. Push to the branch: git push origin feature/my-feature
5. Submit a pull request

Development Setup

# Clone the repository
git clone https://github.com/iamprovy-dev/kernspark-js.git
cd kernspark/packages/kernspark-elysiajs

# Install dependencies
npm install

# Build
npm run build

# Run lint
npm run lint

# Run tests
npm test

Code Standards

• Use TypeScript with strict mode
• Follow the existing code style (2-space indentation, semicolons)
• Ensure all tests pass before submitting PR

License

Apache-2.0

Author

Providence Chikukwa

• Email: [email protected]
• GitHub: https://github.com/iamprovy-dev
• LinkedIn: https://www.linkedin.com/in/provychikukwa
• Organization: SyncAfrica Business Solutions