RegisteredDbContextFactoryTests.cs

using FluentAssertions;
using Microsoft.EntityFrameworkCore;
using Slant.Entity.Tests.Helpers;
using Slant.Entity.Tests.Models;
using System;
using Xunit;

namespace Slant.Entity.Tests
{
    public sealed class RegisteredDbContextFactoryTests : IDisposable
    {
        // Create a SQLite in-memory database which will last the duration of the test
        private readonly SqliteMemoryDatabaseLifetimeManager _databaseManager = new();
        private readonly RegisteredDbContextFactory _dbContextFactory = new();

        public void Dispose()
        {
            _databaseManager.Dispose();
        }

        [Fact]
        public void RegisteredDbContextFactory_should_call_registered_factory_function_for_type()
        {
            var connectionString = _databaseManager.ConnectionString;
            var testDbContextFactoryCallCount = 0;
            var emptyDbContextFactoryCallCount = 0;

            // Arrange - register factory functions for the TestDbContext and EmptyDbContext types
            _dbContextFactory.RegisterDbContextType<TestDbContext>(() =>
                { testDbContextFactoryCallCount += 1; return new TestDbContext(connectionString); });

            _dbContextFactory.RegisterDbContextType<EmptyDbContext>(() =>
                { emptyDbContextFactoryCallCount += 1; return new EmptyDbContext(); });

            // Act - ask the factory for some DbContexts
            var testDbContext1 = _dbContextFactory.CreateDbContext<TestDbContext>();
            var testDbContext2 = _dbContextFactory.CreateDbContext<TestDbContext>();
            var emptyDbContext = _dbContextFactory.CreateDbContext<EmptyDbContext>();

            // Assert
            testDbContextFactoryCallCount.Should().Be(2);
            emptyDbContextFactoryCallCount.Should().Be(1);

            testDbContext1.Should().NotBeNull();
            testDbContext2.Should().NotBeNull();
            emptyDbContext.Should().NotBeNull();

            testDbContext1.Should().NotBeSameAs(testDbContext2);

            var testDbContext1ConnectionString = testDbContext1.Database.GetDbConnection().ConnectionString;
            testDbContext1ConnectionString.Should().Be(connectionString);

            var testDbContext2ConnectionString = testDbContext2.Database.GetDbConnection().ConnectionString;
            testDbContext2ConnectionString.Should().Be(connectionString);
        }
    }
}