multitenantkit/adapter-system-system-clock

System adapter that implements clock functionality using real system time.

Overview

This package provides a concrete implementation of the ClockPort interface from multitenantkit/domain-contracts, using JavaScript's built-in Date object.

Installation

This package is part of the MultiTenantKit monorepo and is installed automatically via workspace dependencies.

Usage

import { SystemClock } from '@multitenantkit/adapter-system-system-clock';

const clock = new SystemClock();
const currentTime = clock.now(); // Returns current Date

Architecture

This adapter follows the Hexagonal Architecture (Ports & Adapters) pattern:

• Port: ClockPort interface defined in multitenantkit/domain-contracts
• Adapter: SystemClock class that implements the port using JavaScript Date

Features

• ✅ Real system time using new Date()
• ✅ Type-safe implementation of ClockPort
• ✅ Zero external dependencies (uses JavaScript built-in Date)
• ✅ Suitable for production use

Why Separate Package?

This adapter is extracted into its own package to:

1. Separation of Concerns: System utilities are independent from persistence logic
2. Reusability: Can be used by any adapter (JSON, Postgres, etc.) without coupling
3. Testability: Easy to mock with fixed time for deterministic tests
4. Clean Architecture: Respects dependency inversion principle

Testing

For testing purposes, you can easily create a mock clock:

class MockClock implements ClockPort {
    constructor(private fixedTime: Date) {}

    now(): Date {
        return this.fixedTime;
    }
}

// Use in tests
const fixedDate = new Date('2024-01-01T00:00:00Z');
const mockClock = new MockClock(fixedDate);

Related Packages

• multitenantkit/domain-contracts - Defines the ClockPort interface
• multitenantkit/adapter-system-crypto-uuid - UUID generation adapter