Workshop about the features of ASP.NET Core 2.2

Prerequisites

• .NET Core SDK 2.2 (2.2.104 at the time of writing) [download]
• Visual Studio 2017 or Visual Studio Code

Middleware

• What is a middleware
• How to create one

Health checks

• What are health checks
• How do they work
• How to set it up

Simple health check to check connection to DB

async ct =>
{
    using (var connection = new SqlConnection(_configuration.GetConnectionString("BlogDatabase")))
    {
        await connection.OpenAsync(ct);
        using (var command = new SqlCommand("SELECT 1", connection))
        {
            await command.ExecuteScalarAsync(ct);
        }

        return HealthCheckResult.Healthy();
    }
}

Healthcheck setup

UseHealthChecks("/healthcheck", new HealthCheckOptions {Predicate = hc => hc.Tags.Contains("db")})

Health checks in ASP.NET Core

Nuget packages:

• AspNetCore.HealthChecks.SqlServer / GitHub

Configuration

• How does it work
• Setup BlogSettings options
  • from .json
  • from .xml
  • from Action<T>

Dependency Injection

• How to use default DI
• What are the limitations
• How to refactor to 3rd party DI (AutoFac)

AutoFac setup

With ConfigureContainer

Program.cs

.ConfigureServices(services => services.AddAutofac())

Startup.cs

public void ConfigureContainer(ContainerBuilder builder)
{
    builder.RegisterType<BlogRepository>().As<IBlogRepository>();
}

Without ConfigureContainer

public IServiceProvider ConfigureServices(IServiceCollection services)
{
    //

    var containerBuilder = new ContainerBuilder();
    containerBuilder.Populate(services);
    containerBuilder.RegisterType<BlogRepository>().As<IBlogRepository>();
    return new AutofacServiceProvider(containerBuilder.Build());
}

Nuget packages:

• Autofac.Extensions.DependencyInjection / Docs
• Scrutor / GitHub

Logging

• Default logging framework
• Adding 3rd party loggers (NLog)

Nuget packages:

• NLog.Web.AspNetCore

Files abstraction

• How to abstract dependency of physical file and write testable code

API Documentation

• Setup Swagger JSON
• Setup Swagger UI
• Create custom ApiInfo view

Nuget packages:

• Swashbuckle.AspNetCore / GitHub

Views

• Difference between Razor Pages and Views
• Introduction to View Components

Razor pages - Introduction to Razor Pages in ASP.NET Core

Razor page directive

@page

Page model

public class BlogModel : PageModel

GET action

public async Task OnGetAsync()
{
   //
}

View components - View components in ASP.NET Core

View Component class

[ViewComponent(Name = "Blog")]
public class BlogComponent : ViewComponent

Invoke action

public Task<IViewComponentResult> InvokeAsync(Blog blog)
{
   //
}

View Component usage

<vc:blog blog="blog"></vc:blog>

Testing

• Startup.cs integration testing
• Code coverage

Collect test coverage

dotnet test .\Workshop.App.Tests\ /p:CollectCoverage=true /p:Exclude="[xunit.*]*"

Integration tests in ASP.NET Core

Nuget packages:

• coverlet.msbuild / GitHub
• Microsoft.AspNetCore.Mvc.Testing