strangler-fig-demo/new/src/New.Infrastructure.Persistence/NewDbContextFactory.cs

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Design;

namespace New.Infrastructure.Persistence;

/// <summary>
/// Design-time-only factory so `dotnet ef migrations add/update` can
/// construct a NewDbContext without a running host (this project has no DI
/// container of its own - New.Api's ServiceCollectionExtensions.AddPersistenceInfrastructure
/// is what wires the real DbContextOptions at runtime, reading
/// ConnectionStrings__New from the environment). Never used outside `dotnet ef`.
/// </summary>
public sealed class NewDbContextFactory : IDesignTimeDbContextFactory<NewDbContext>
{
    public NewDbContext CreateDbContext(string[] args)
    {
        var optionsBuilder = new DbContextOptionsBuilder<NewDbContext>();
        optionsBuilder.UseNpgsql("Host=localhost;Port=5432;Database=newdb;Username=postgres;Password=postgres");
        return new NewDbContext(optionsBuilder.Options);
    }
}