Nabs.Launchpad.Core.SeedData 10.0.180

Nabs Launchpad Core Seed Data Library

A .NET 9 library providing interfaces and abstractions for database seeding and migration operations in the Nabs Launchpad framework.

Overview

The Nabs.Launchpad.Core.SeedData library defines core interfaces for managing database initialization tasks including:

• Database schema migrations
• Test data generation and seeding
• Development environment data setup

This library provides the contracts that implementations can use to handle database setup operations in a consistent manner across the Launchpad platform.

Features

• Migration Processing: Interface for handling database schema migrations
• Seed Data Processing: Interface for populating databases with initial or test data
• Async Support: All operations support cancellation tokens and async patterns
• Framework Integration: Designed to work seamlessly with dependency injection and hosted services

Core Interfaces

ISeedDataProcessor

Defines a contract for processing seed data operations:

public interface ISeedDataProcessor
{
    Task ProcessAsync(CancellationToken stoppingToken);
}

Use this interface to implement classes that populate your database with:

• Initial application data
• Test data for development environments
• Sample data for demonstrations

IMigrationProcessor

Defines a contract for handling database migrations:

public interface IMigrationProcessor
{
    Task MigrateAsync(CancellationToken stoppingToken);
}

Use this interface to implement classes that:

• Apply database schema changes
• Execute migration scripts
• Ensure database schema is up-to-date

Dependencies

• .NET 9: Target framework
• Bogus: Fake data generation library for creating realistic test data

Usage Examples

Implementing ISeedDataProcessor

public class UserSeedDataProcessor : ISeedDataProcessor
{
    private readonly IUserRepository _userRepository;
    private readonly Faker<User> _userFaker;

    public UserSeedDataProcessor(IUserRepository userRepository)
    {
        _userRepository = userRepository;
        _userFaker = new Faker<User>()
            .RuleFor(u => u.FirstName, f => f.Name.FirstName())
            .RuleFor(u => u.LastName, f => f.Name.LastName())
            .RuleFor(u => u.Email, f => f.Internet.Email());
    }

    public async Task ProcessAsync(CancellationToken stoppingToken)
    {
        if (await _userRepository.AnyAsync(stoppingToken))
            return; // Data already exists

        var users = _userFaker.Generate(100);
        await _userRepository.AddRangeAsync(users, stoppingToken);
    }
}

Implementing IMigrationProcessor

public class DatabaseMigrationProcessor : IMigrationProcessor
{
    private readonly ApplicationDbContext _context;

    public DatabaseMigrationProcessor(ApplicationDbContext context)
    {
        _context = context;
    }

    public async Task MigrateAsync(CancellationToken stoppingToken)
    {
        await _context.Database.MigrateAsync(stoppingToken);
    }
}

Dependency Injection Registration

services.AddScoped<ISeedDataProcessor, UserSeedDataProcessor>();
services.AddScoped<IMigrationProcessor, DatabaseMigrationProcessor>();

Using in Hosted Service

public class DatabaseInitializationService : IHostedService
{
    private readonly IMigrationProcessor _migrationProcessor;
    private readonly ISeedDataProcessor _seedDataProcessor;

    public DatabaseInitializationService(
        IMigrationProcessor migrationProcessor,
        ISeedDataProcessor seedDataProcessor)
    {
        _migrationProcessor = migrationProcessor;
        _seedDataProcessor = seedDataProcessor;
    }

    public async Task StartAsync(CancellationToken cancellationToken)
    {
        await _migrationProcessor.MigrateAsync(cancellationToken);
        await _seedDataProcessor.ProcessAsync(cancellationToken);
    }

    public Task StopAsync(CancellationToken cancellationToken) => Task.CompletedTask;
}

Integration with Launchpad

This library is part of the larger Nabs Launchpad framework and integrates with:

• Core.Testing.Silos: Provides test data for Orleans silo testing
• Core.Persistence: Works with Entity Framework contexts for data operations
• Core.Context: Integrates with application database contexts

Best Practices

1. Environment-Specific Data: Only seed data appropriate for the current environment
2. Idempotent Operations: Ensure seed operations can be run multiple times safely
3. Performance Considerations: Use bulk operations for large datasets
4. Error Handling: Implement proper error handling and logging
5. Cancellation Support: Always respect cancellation tokens for graceful shutdowns

Testing

The library includes comprehensive unit tests in the Launchpad.Core.SeedData.UnitTests project to ensure reliability and correctness of the interfaces and any shared implementations.

Contributing

This library follows the Nabs Launchpad coding standards:

• Use C# 13 features and latest language constructs
• Follow nullable reference types conventions
• Implement proper async/await patterns
• Include comprehensive unit tests

License

Copyright � Net Advantage Business Solutions