MockDb Helper

MockDb.cs

namespace MockDbHelper
{
    using Microsoft.Data.Sqlite;
    using Microsoft.EntityFrameworkCore;
    using System;

    public class MockDb<TContext> : IDisposable
        where TContext : DbContext
    {
        private readonly SqliteConnection _connection = new SqliteConnection("DataSource=:memory:");

        public TContext GetContext => (TContext)Activator.CreateInstance(typeof(TContext), GetOptions);

        public MockDb()
        {
            _connection.Open();

            // Create the schema in the database
            using var context = (TContext)Activator.CreateInstance(typeof(TContext), GetOptions);
            context.Database.EnsureCreated();
        }

        public void Dispose()
        {
            _connection.Close();
        }

        private DbContextOptions<TContext> GetOptions =>
            new DbContextOptionsBuilder<TContext>()
                .UseSqlite(_connection)
                .Options;
    }
}

namespace MockDbHelper.Example
{
    using Moq;
    using System;
    using System.Threading.Tasks;
    using Xunit;

    public class Tests
    {
        [Fact]
        public async Task DbTest()
        {
            // Act
            using var mockDb = new MockDb<DbContext>();
            using (var context = mockDb.GetContext)
            {
                // Perform seed actions
                setupContext.SaveChanges();
            }
        }
    }
}