docker-docs/content/guides/testcontainers-dotnet-aspnet-core/create-project.md

title, linkTitle, description, weight

title	linkTitle	description	weight
Set up the project	Create the project	Set up an ASP.NET Core Razor Pages project with integration test dependencies.	10

Background

This guide builds on top of Microsoft's Integration tests in ASP.NET Core documentation. The original sample uses an in-memory SQLite database as the backing store for integration tests. You'll replace SQLite with a real Microsoft SQL Server instance running in a Docker container using Testcontainers.

You can find the original code sample in the dotnet/AspNetCore.Docs.Samples repository.

Clone the repository

Clone the Testcontainers guide repository and change into the project directory:

$ git clone https://github.com/testcontainers/tc-guide-testing-aspnet-core.git
$ cd tc-guide-testing-aspnet-core

Project structure

The solution contains two projects:

RazorPagesProject.sln
├── src/RazorPagesProject/              # ASP.NET Core Razor Pages app
└── tests/RazorPagesProject.Tests/      # xUnit integration tests

Application project

The application project (src/RazorPagesProject/RazorPagesProject.csproj) is a Razor Pages web app that uses Entity Framework Core with SQLite as its default database provider:

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>net9.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="7.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore" Version="7.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="7.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Identity.UI" Version="7.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="7.0.0">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
  </ItemGroup>

</Project>

The ApplicationDbContext stores Message entities and provides methods to query and manage them:

public class ApplicationDbContext : IdentityDbContext
{
    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
        : base(options)
    {
    }

    public virtual DbSet<Message> Messages { get; set; }

    public async virtual Task<List<Message>> GetMessagesAsync()
    {
        return await Messages
            .OrderBy(message => message.Text)
            .AsNoTracking()
            .ToListAsync();
    }

    public async virtual Task AddMessageAsync(Message message)
    {
        await Messages.AddAsync(message);
        await SaveChangesAsync();
    }

    public async virtual Task DeleteAllMessagesAsync()
    {
        foreach (Message message in Messages)
        {
            Messages.Remove(message);
        }

        await SaveChangesAsync();
    }

    public async virtual Task DeleteMessageAsync(int id)
    {
        var message = await Messages.FindAsync(id);

        if (message != null)
        {
            Messages.Remove(message);
            await SaveChangesAsync();
        }
    }

    public void Initialize()
    {
        Messages.AddRange(GetSeedingMessages());
        SaveChanges();
    }

    public static List<Message> GetSeedingMessages()
    {
        return new List<Message>()
        {
            new Message(){ Text = "You're standing on my scarf." },
            new Message(){ Text = "Would you like a jelly baby?" },
            new Message(){ Text = "To the rational mind, nothing is inexplicable; only unexplained." }
        };
    }
}

Test project

The test project (tests/RazorPagesProject.Tests/RazorPagesProject.Tests.csproj) includes xUnit, the ASP.NET Core testing infrastructure, and the Testcontainers MSSQL module:

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>net9.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="AngleSharp" Version="0.17.1" />
    <PackageReference Include="Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore" Version="7.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="7.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Identity.UI" Version="7.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="7.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="7.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="7.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="7.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="7.0.0">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>

    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.4.0" />

    <PackageReference Include="Testcontainers.MsSql" Version="3.0.0" />
    <PackageReference Include="xunit" Version="2.4.2" />
    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
  </ItemGroup>

  <ItemGroup>
    <ProjectReference Include="..\..\src\RazorPagesProject\RazorPagesProject.csproj" />
  </ItemGroup>

  <ItemGroup>
    <Content Update="xunit.runner.json">
      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
    </Content>
  </ItemGroup>

</Project>

The key dependencies are:

• Microsoft.AspNetCore.Mvc.Testing - provides WebApplicationFactory for bootstrapping the app in tests
• Microsoft.EntityFrameworkCore.SqlServer - the SQL Server database provider for Entity Framework Core
• Testcontainers.MsSql - the Testcontainers module for Microsoft SQL Server

Existing SQLite-based test factory

The original project includes a CustomWebApplicationFactory that replaces the application's database with an in-memory SQLite instance:

public class CustomWebApplicationFactory<TProgram>
    : WebApplicationFactory<TProgram> where TProgram : class
{
    protected override void ConfigureWebHost(IWebHostBuilder builder)
    {
        builder.ConfigureServices(services =>
        {
            var dbContextDescriptor = services.SingleOrDefault(
                d => d.ServiceType ==
                    typeof(DbContextOptions<ApplicationDbContext>));

            services.Remove(dbContextDescriptor);

            var dbConnectionDescriptor = services.SingleOrDefault(
                d => d.ServiceType ==
                    typeof(DbConnection));

            services.Remove(dbConnectionDescriptor);

            // Create open SqliteConnection so EF won't automatically close it.
            services.AddSingleton<DbConnection>(container =>
            {
                var connection = new SqliteConnection("DataSource=:memory:");
                connection.Open();

                return connection;
            });

            services.AddDbContext<ApplicationDbContext>((container, options) =>
            {
                var connection = container.GetRequiredService<DbConnection>();
                options.UseSqlite(connection);
            });
        });

        builder.UseEnvironment("Development");
    }
}

While this approach works, SQLite has behavioral differences from the database you'd use in production. In the next section, you'll replace it with a Testcontainers-managed Microsoft SQL Server instance.