QWERTYkez.Mensura/QWERTYkez.Mensura.Tests/TestEntity.cs

using Microsoft.Data.Sqlite;
using Microsoft.EntityFrameworkCore;

namespace QWERTYkez.Mensura.Tests
{
    public class TestEntity1
    {
        public int Id { get; set; }
        public Length Length { get; set; }
    }

    public class TestEntity2
    {
        public int Id { get; set; }
        public double Length { get; set; }
    }

    public class SharedDbContext(DbContextOptions<SharedDbContext> options) : DbContext(options)
    {
        public DbSet<TestEntity1> Entities1 { get; set; }
        public DbSet<TestEntity2> Entities2 { get; set; }

        protected override void ConfigureConventions(ModelConfigurationBuilder configurationBuilder)
        {
            configurationBuilder.UseMensuraUnits();
        }
    }

    public class IdentityConversionTest : IDisposable
    {
        private readonly SqliteConnection _connection;

        public IdentityConversionTest()
        {
            _connection = new SqliteConnection("Filename=:memory:");
            _connection.Open();
        }

        public void Dispose()
        {
            _connection?.Dispose();
            GC.SuppressFinalize(this);
        }

        [Fact]
        public void Length_And_Double_Are_Stored_Identically()
        {
            // 1. Сохраняем Length → читаем как double
            double savedDoubleFromLength;
            using (var context = new SharedDbContext(new DbContextOptionsBuilder<SharedDbContext>().UseSqlite(_connection).Options))
            {
                context.Database.EnsureCreated();
                var expectedLength = Length.Meter; // 1000 мм
                context.Entities1.Add(new TestEntity1 { Length = expectedLength });
                context.SaveChanges();

                using var cmd = context.Database.GetDbConnection().CreateCommand();
                cmd.CommandText = "SELECT Length FROM Entities1";
                savedDoubleFromLength = (double)cmd.ExecuteScalar()!;
            }

            // 2. Сохраняем double → читаем как Length
            double savedDoubleFromDouble = 1234.5;
            using (var context = new SharedDbContext(new DbContextOptionsBuilder<SharedDbContext>().UseSqlite(_connection).Options))
            {
                context.Database.EnsureCreated();
                context.Entities2.Add(new TestEntity2 { Length = savedDoubleFromDouble });
                context.SaveChanges();

                using var cmd = context.Database.GetDbConnection().CreateCommand();
                cmd.CommandText = "SELECT Length FROM Entities2";
                savedDoubleFromDouble = (double)cmd.ExecuteScalar()!; // должно быть 1234.5
            }

            // 3. Проверяем, что сырые значения сохранены корректно
            Assert.Equal(1000.0, savedDoubleFromLength);
            Assert.Equal(1234.5, savedDoubleFromDouble);

            // 4. Проверяем обратимость: читаем из Entities1 как TestEntity2
            using (var context = new SharedDbContext(new DbContextOptionsBuilder<SharedDbContext>().UseSqlite(_connection).Options))
            {
                var fromLengthTable = context.Entities2
                    .FromSqlRaw("SELECT Id, Length FROM Entities1")
                    .First();
                Assert.Equal(1000.0, fromLengthTable.Length);
            }

            // 5. Проверяем обратимость: читаем из Entities2 как TestEntity1
            using (var context = new SharedDbContext(new DbContextOptionsBuilder<SharedDbContext>().UseSqlite(_connection).Options))
            {
                var fromDoubleTable = context.Entities1
                    .FromSqlRaw("SELECT Id, Length FROM Entities2")
                    .First();
                Assert.Equal(1234.5, (double)fromDoubleTable.Length);
            }
        }
    }
}