Avionics

High-Assurance Airline Reservation System demonstrating "Robust TypeScript" with Effect.

Overview

Avionics simulates the critical lifecycle of a commercial airline reservation system, focusing on reliability and correctness in a high-concurrency environment.

Core Concepts

• Inventory Management: Real-time seat availability with strict consistency (Zero Overbooking).
• Complex Booking Lifecycle: PassengerNameRecord (PNR) orchestration (Hold → Payment → Ticketing).
• Resiliency: Recovery from distributed failures using Sagas.
• Zero-Throw Policy: All business and technical errors are typed values (Effect<A, E, R>).

Architecture

The project follows Hexagonal Architecture (Ports & Adapters) to decouple business logic from infrastructure.

Domain Entities Diagram

classDiagram
    namespace Supply {
        class Flight {
            +FlightNumber flightNumber
            +Schedule schedule
            +Route route
        }

        class FlightInventory {
            +Buckets availability
            +int version
        }
    }

    namespace Demand {
        class Booking {
            +PnrCode pnrCode
            +BookingStatus status
            +Date expiresAt
            +isPayable(): boolean
        }

        class BookingSegment {
            +Money price
            +CabinClass cabin
        }

        class Passenger {
            +String firstName
            +String lastName
            +Email email
            +Date dateOfBirth
            +Gender gender
            +PassengerType passengerType
        }
    }

    namespace Contract {
        class Ticket {
            +TicketNumber ticketNumber
            +TicketStatus status
            +PnrCode pnrCode
            +String passengerName
            +Coupon[] coupons
            +Date issuedAt
        }
    }

    %% Relationships
    FlightInventory --> Flight : Belongs To
    Booking ..> FlightInventory : Holds Seat
    Booking --> Ticket : Issues

    Booking *-- BookingSegment : Composition
    Booking *-- Passenger : Composition

    Ticket ..> Booking : References

    %% Styling
    style Flight fill:#4f4f4f,stroke:#fff
    style FlightInventory fill:#4f4f4f,stroke:#fff
    style Booking fill:#0ea5e9,stroke:#fff,color:#fff
    style BookingSegment fill:#0ea5e9,stroke:#fff,color:#fff
    style Passenger fill:#0ea5e9,stroke:#fff,color:#fff
    style Ticket fill:#10b981,stroke:#fff,color:#fff

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Workspace Structure

• packages/domain: The Core. Pure business logic, Entities, and Value Objects. Dependencies: effect and @faker-js/faker only.
• packages/application: The Orchestrator. Use Cases, Ports (Repository Interfaces), and Sagas.
• packages/infrastructure: The Adapters. Database implementation (Postgres), External APIs (Polar, Resend).
• apps/web: The Interface. Vite application consuming the core via adapters.

Tech Stack

• Runtime: Node.js >=24
• Monorepo: Turborepo + pnpm (Strict Mode)
• Framework: Effect 3.x (Schema, Concurrency, Error Handling)
• Testing: Vitest + Faker
• Linting: Biome.js

Quick Start

1. Install Dependencies

   pnpm install

2. Start Development

   pnpm dev

3. Run Tests

   pnpm test
   # or
   pnpm test -F <packageName or appName>

Development Commands

Command	Description
pnpm build	Build all apps and packages
pnpm test:coverage	Run tests with V8 coverage reports
pnpm check	Run Biome lint and format checks
pnpm clean	Clean generic node_modules and build artifacts
pnpm typecheck	Run TypeScript type checking

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Maintained by Bakate.