maraphon-app/tests/Marathon.Infrastructure.Tests/Persistence/InMemoryDbFixture.cs

using Marathon.Infrastructure.Persistence;
using Microsoft.Data.Sqlite;
using Microsoft.EntityFrameworkCore;

namespace Marathon.Infrastructure.Tests.Persistence;

/// <summary>
/// Shared in-memory SQLite fixture for persistence tests.
/// Uses a named in-memory database with a shared cache connection so the schema
/// created in <c>EnsureCreated()</c> is visible across the lifetime of each test.
/// </summary>
public sealed class InMemoryDbFixture : IDisposable
{
    private readonly SqliteConnection _keepAliveConnection;

    public MarathonDbContext DbContext { get; }

    public InMemoryDbFixture()
    {
        // Each fixture instance gets its own in-memory database so xUnit's per-test
        // isolation isn't violated when tests run in parallel within a class
        // (the previous shared "marathon_tests" name caused state contamination).
        var dbName = $"marathon_tests_{Guid.NewGuid():N}";
        var connectionString = $"Data Source={dbName};Mode=Memory;Cache=Shared";

        // Keep a single connection open so the named in-memory DB lives until the
        // fixture is disposed.
        _keepAliveConnection = new SqliteConnection(connectionString);
        _keepAliveConnection.Open();

        var options = new DbContextOptionsBuilder<MarathonDbContext>()
            .UseSqlite(connectionString)
            .Options;

        DbContext = new MarathonDbContext(options);
        DbContext.Database.EnsureCreated();
    }

    public void Dispose()
    {
        DbContext.Dispose();
        _keepAliveConnection.Dispose();
    }
}