Mycena Backend Kit

A collection of utility functions, guards, and decorators for NestJS backend applications.

Installation

npm install mycena-backend-kit

Features

Permission System

Permission Guard

A NestJS guard that handles permission-based access control for both HTTP and WebSocket routes.

• Validates x-user and x-permission headers
• Supports special internal-system user ID for unrestricted access
• Works with both HTTP and WebSocket contexts

Usage:

import { PermissionGuard } from 'mycena-backend-kit';

@UseGuards(PermissionGuard)
@Controller('example')
export class ExampleController {
  // Your controller methods
}

Decorators

1. Permission Decorator

import { Permission } from 'mycena-backend-kit';

@Permission('read:users', 'write:users')
@Get('users')
async getUsers() {
  // Your method implementation
}

2. Public Decorator (Skip permission check)

import { Public } from 'mycena-backend-kit';

@Public()
@Get('public-endpoint')
async publicMethod() {
  // Your method implementation
}

Utility Functions

mapById

Converts an array of objects with ID properties into an object map.

import { mapById } from 'mycena-backend-kit';

const users = [
  { id: 1, name: 'John' },
  { id: 2, name: 'Jane' },
];

const userMap = mapById(users);
// Result: { '1': { id: 1, name: 'John' }, '2': { id: 2, name: 'Jane' } }

mapToArray

Converts an object map back to an array.

import { mapToArray } from 'mycena-backend-kit';

const userMap = {
  '1': { id: 1, name: 'John' },
  '2': { id: 2, name: 'Jane' },
};

const users = mapToArray(userMap);
// Result: [{ id: 1, name: 'John' }, { id: 2, name: 'Jane' }]

Interfaces

GetPage

Interface for pagination parameters.

interface GetPage<T> {
  skip: number;
  size: number;
}

Requirements

• Node.js
• NestJS ^11.1.0

License

ISC