Futurum.WebApiEndpoint.Micro 2.0.1

Futurum.WebApiEndpoint.Micro

A dotnet library that allows you to build WebApiEndpoints using a vertical slice architecture approach in a structured way. It's built on top of dotnet 8 and minimal apis.

[WebApiEndpoint("greeting")]
public class GreetingWebApiEndpoint
{
    protected override void Build(IEndpointRouteBuilder builder)
    {
        builder.MapGet("/hello", HelloHandler);
        builder.MapGet("/goodbye", GoodbyeHandler);
    }

    private static Ok<string> HelloHandler(HttpContext context, string name) =>
        $"Hello {name}".ToOk();

    private static Ok<string> GoodbyeHandler(HttpContext context, string name) =>
        $"Goodbye {name}".ToOk();
}

• Vertical Slice Architecture, gives you the ability to add new features without changing existing code
• Structured way of building WebApiEndpoints using minimal apis
• Easy setup
• Developer friendly, with a simple API and with a full suite of samples and tests
• Full support and built on top of minimal apis
• Full support for OpenApi
• Full support for TypedResults
• Supports uploading file(s) with additional JSON payload
• Api Versioning baked-in
• Built in sandbox runner with full TypedResults support, catching unhandled exceptions and returning a ProblemDetails response
• Autodiscovery of WebApiEndpoint(s), based on Source Generators
• Roslyn Analysers to help build your WebApiEndpoint(s), using best practices
• Built on dotnet 8
• Built in use of ProblemDetails support
• Tested solution
• Comprehensive samples
• Convention Customisation

What is a WebApiEndpoint?

• It's a vertical slice / feature of your application
• The vertical slice is a self-contained unit of functionality
• Collection of WebApi's that share a route prefix and version. They can also share things like EndpointFilters, RateLimiting, etc.

Easy setup

• Add the NuGet package ( futurum.webapiendpoint.micro ) to your project
• Update program.cs as per here
• Create a new class that implements IWebApiEndpoint
• Add the WebApiEndpoint attribute to the class, if you want to specify a specific route prefix and tag
• Add the WebApiEndpointVersion attribute to the class, if you want to specify a specific ApiVersion
• Implement the Register method and add minimal api(s) as per usual
• Optionally implement the Configure method to configuration the WebApiEndpoint

program.cs

using Futurum.WebApiEndpoint.Micro;
using Futurum.WebApiEndpoint.Micro.Sample;

var builder = WebApplication.CreateBuilder(args);

builder.Services
       .AddWebApiEndpoints(new WebApiEndpointConfiguration(WebApiEndpointVersions.V1_0))
       .AddWebApiEndpointsForFuturumWebApiEndpointMicroSample();

var app = builder.Build();

app.UseWebApiEndpoints();

if (app.Environment.IsDevelopment())
{
    app.UseWebApiEndpointsOpenApi();
}

app.Run();

AddWebApiEndpoints

Allows you to configure:

• GlobalRoutePrefix (optional)
  • This is used if you want to specify a global route prefix for all WebApiEndpoint
  • e.g. "/api"
• DefaultApiVersion (mandatory)
  • This is used if a specific ApiVersion is not provided for a specific WebApiEndpoint
• DefaultOpenApiInfo (optional)
  • This is used if a specific OpenApiInfo is not provided for a specific ApiVersion
• OpenApiDocumentVersions (optional)
  • Allowing you to have different OpenApiInfo per ApiVersion
• VersionPrefix (optional)
• VersionFormat (optional)
  • uses 'Asp.Versioning.ApiVersionFormatProvider'

builder.Services.AddWebApiEndpoints(new WebApiEndpointConfiguration(WebApiEndpointVersions.V1_0)
{
    DefaultOpenApiInfo = new OpenApiInfo
    {
        Title = "Futurum.WebApiEndpoint.Micro.Sample",
    },
    OpenApiDocumentVersions =
    {
        {
            WebApiEndpointVersions.V1_0, 
            new OpenApiInfo
            {
                Title = "Futurum.WebApiEndpoint.Micro.Sample v1"
            }
        }
    }
});

AddWebApiEndpointsFor... (per project containing WebApiEndpoints)

This will be automatically created by the source generator.

e.g.

builder.Services.AddWebApiEndpointsForFuturumWebApiEndpointMicroSample();

UseWebApiEndpoints

Adds the WebApiEndpoints to the pipeline

app.UseWebApiEndpoints();

UseWebApiEndpointsOpenApi

Register the OpenApi UI (Swagger and SwaggerUI) middleware

app.UseWebApiEndpointsOpenApi();

WebApiEndpoint

Build

You can map your minimal apis for this WebApiEndpoint in the Build method.

The IEndpointRouteBuilder parameter is already:

• configured with the API versioning
• configured with the route prefix
• been through the optional Configure method in the same class

protected override void Build(IEndpointRouteBuilder builder)
{
}

Full example

Weather

[WebApiEndpoint("weather")]
public class WeatherWebApiEndpoint
{
    private static readonly string[] Summaries =
    {
        "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"
    };

    protected override void Build(IEndpointRouteBuilder builder)
    {
        builder.MapGet("/", GetHandler);
    }

    private static Ok<IEnumerable<WeatherForecastDto>> GetHandler(HttpContext httpContext, CancellationToken cancellationToken) =>
        Enumerable.Range(1, 5)
                  .Select(index => new WeatherForecastDto(DateOnly.FromDateTime(DateTime.Now.AddDays(index)), Random.Shared.Next(-20, 55), Summaries[Random.Shared.Next(Summaries.Length)]))
                  .ToOk();
}

File download

[WebApiEndpoint("bytes", "feature")]
public class BytesWebApiEndpoint
{
    protected override void Build(IEndpointRouteBuilder builder)
    {
        builder.MapGet("download", DownloadHandler);
    }

    private static Results<NotFound, FileContentHttpResult, BadRequest<ProblemDetails>> DownloadHandler(HttpContext context)
    {
        return Run(Execute, context, "Failed to read file");

        Results<NotFound, FileContentHttpResult> Execute()
        {
            var path = "./Data/hello-world.txt";

            if (!File.Exists(path))
            {
                return TypedResults.NotFound();
            }

            var bytes = File.ReadAllBytes(path);
            return TypedResults.Bytes(bytes, MediaTypeNames.Application.Octet, "hello-world.txt");
        }
    }
}

Configure

You can optionally configure the WebApiEndpoint in the Configure method

protected override RouteGroupBuilder Configure(RouteGroupBuilder groupBuilder, WebApiEndpointVersion webApiEndpointVersion)
{
}

This allows you to set properties on the RouteGroupBuilder. This will effect all minimal apis in the Register method.

You can also configure it differently per ApiVersion.

This ia a good place to add a EndpointFilter

groupBuilder.AddEndpointFilter<CustomEndpointFilter>();

This ia a good place to add a RateLimiting

groupBuilder.RequireRateLimiting(RateLimiting.SlidingWindow.Policy);

This ia a good place to add a OutputCache

groupBuilder.CacheOutput(OutputCaching.ExpiryIn10Seconds.Policy);

This ia a good place to add Security

groupBuilder.RequireAuthorization(Authorization.Permission.Admin);

Sandbox runner

Run and RunAsync - If your code returns an IResult

Comprehensive set of extension methods, to run your code in a sandbox

• If your code does not throw an unhandled exception, then the existing return remains the same.
• If your code does throw an unhandled exception, then a BadRequest<ProblemDetails> will be returned, with the appropriate details set on the ProblemDetails.

The returned Results<...> type is always augmented to additionally include BadRequest<ProblemDetails>

TIResult1 -> Results<TIResult1, BadRequest<ProblemDetails>>

Results<TIResult1, TIResult2> -> Results<TIResult1, TIResult2, BadRequest<ProblemDetails>>

Results<TIResult1, TIResult2, TIResult3> -> Results<TIResult1, TIResult2, TIResult3, BadRequest<ProblemDetails>>

Results<TIResult1, TIResult2, TIResult3, TIResult4> -> Results<TIResult1, TIResult2, TIResult3, TIResult4, BadRequest<ProblemDetails>>

Results<TIResult1, TIResult2, TIResult3, TIResult4, TIResult5> -> Results<TIResult1, TIResult2, TIResult3, TIResult4, TIResult5, BadRequest<ProblemDetails>>

Results has a maximum of 6 types. So 5 are allowed leaving one space left for the BadRequest<ProblemDetails>.

Example use

private static Results<NotFound, FileStreamHttpResult, BadRequest<ProblemDetails>> DownloadHandler(HttpContext context)
{
    return Run(Execute, context, "Failed to read file");

    Results<NotFound, FileStreamHttpResult> Execute()
    {
        var path = "./Data/hello-world.txt";

        if (!File.Exists(path))
        {
            return TypedResults.NotFound();
        }

        var fileStream = File.OpenRead(path);
        return TypedResults.File(fileStream, MediaTypeNames.Application.Octet, "hello-world.txt");
    }
}

In this example the Execute method is being wrapped by the runner. It returns:

• a NotFound if the file does not exist
• a FileStreamHttpResult if the file exists

Results<NotFound, FileStreamHttpResult>

The Run / RunAsync extension method will change this to add BadRequest<ProblemDetails>.

Results<NotFound, FileStreamHttpResult, BadRequest<ProblemDetails>>

Note: It is recommended to add the following to your GlobalUsings.cs file.

global using static Futurum.WebApiEndpoint.Micro.WebApiEndpointRunner;

This means you can use the helper functions without having to specify the namespace. As in the examples.

RunToOk and RunToOkAsync - If your code returns an T (not a IResult)

Comprehensive set of extension methods, to run your code in a sandbox

• If your code does not throw an unhandled exception, then the existing return remains the same, but will be wrapped in an Ok.
• If your code does throw an unhandled exception, then a BadRequest<ProblemDetails> will be returned, with the appropriate details set on the ProblemDetails.

The returned type from Run and RunAsync is always augmented to additionally include BadRequest<ProblemDetails>

_ -> Results<Ok, BadRequest<ProblemDetails>>

T -> Results<Ok<T>, BadRequest<ProblemDetails>>

Example use

private static Results<Ok<IAsyncEnumerable<Todo>>, BadRequest<ProblemDetails>> GetAllHandler(HttpContext context, SqliteConnection db)
{
    return RunToOk(Execute, context, "Failed to get todos");

    IAsyncEnumerable<Todo> Execute() =>
        db.QueryAsync<Todo>("SELECT * FROM Todos");
}

In this example the Execute method returns IAsyncEnumerable<Todo>

IAsyncEnumerable<Todo>

The RunToOk / RunToOkAsync extension method will

• change the T to Ok<T>
• add BadRequest<ProblemDetails>.

Results<Ok<IAsyncEnumerable<Todo>>, BadRequest<ProblemDetails>>

Note: It is recommended to add the following to your GlobalUsings.cs file.

global using static Futurum.WebApiEndpoint.Micro.WebApiEndpointRunner;

This means you can use the helper functions without having to specify the namespace. As in the examples.

Uploading file(s) with additional JSON payload

Upload single file and payload

Use the FormFileWithPayload type to upload a single file and a JSON payload

private static Task<Results<Ok<FileDetailsWithPayloadDto>, BadRequest<ProblemDetails>>> UploadWithPayloadHandler(HttpContext context, FormFileWithPayload<PayloadDto> fileWithPayload)
{
    return RunAsync(Execute, context, ToOk, "Failed to read file");

    async Task<FileDetailsWithPayloadDto> Execute()
    {
        var tempFile = Path.GetTempFileName();
        await using var stream = File.OpenWrite(tempFile);
        await fileWithPayload.File.CopyToAsync(stream);

        return new FileDetailsWithPayloadDto(fileWithPayload.File.FileName, fileWithPayload.Payload.Name);
    }
}

Upload multiple files and payload

Use the FormFilesWithPayload type to upload multiple files and a JSON payload

private static Task<Results<Ok<IEnumerable<FileDetailsWithPayloadDto>>, BadRequest<ProblemDetails>>> UploadsWithPayloadHandler(
    HttpContext context, FormFilesWithPayload<PayloadDto> filesWithPayload)
{
    return RunAsync(Execute, context, ToOk, "Failed to read file");

    async Task<IEnumerable<FileDetailsWithPayloadDto>> Execute()
    {
        var fileDetails = new List<FileDetailsWithPayloadDto>();

        foreach (var file in filesWithPayload.Files)
        {
            var tempFile = Path.GetTempFileName();
            await using var stream = File.OpenWrite(tempFile);
            await file.CopyToAsync(stream);

            fileDetails.Add(new FileDetailsWithPayloadDto(file.FileName, filesWithPayload.Payload.Name));
        }

        return fileDetails;
    }
}

Additional helper functions

ToOk

Converts a T to an Ok<T>.

ToOk

ToCreated

Converts a () to a Created.

ToCreated<string>

By default it will take the location from the HttpContext.Request.Path.

or

Converts a T to a Created<T>.

This can be overridden by passing in a string.

ToCreated<T>("/api/articles")

ToAccepted

Converts a () to a Accepted.

ToAccepted<string>

By default it will take the location from the HttpContext.Request.Path.

or

Converts a T to a Accepted<T>.

By default it will take the location from the HttpContext.Request.Path.

This can be overridden by passing in a string.

ToAccepted<T>("/api/articles")

Comprehensive samples

There are examples showing the following:

• A basic blog CRUD implementation
• The ToDo sample from Damian Edwards here
• AsyncEnumerable
• Bytes file download
• EndpointFilter on a specific WebApiEndpoint
• Exception handling
• File(s) upload
• File(s) upload with Payload
• File download
• OpenApi versioning
• Output Caching
• Rate Limiting
• Security with a basic JWT example on a specific WebApiEndpoint
• Weather Forecast
• Addition project containing WebApiEndpoints

Security example

How to use in Swagger UI:

1. Run the Sample project
2. In the Swagger UI, go to the 'Security' 'Login' endpoint
3. Set the following Username = user1 Password = password1 SetPermissions = true SetClaim = true SetRole = true
4. Copy the value returned without double quotes.
5. Go to the 'Security' 'Protected' endpoint
6. Click on the padlock
7. In the value textbox, enter "Bearer " (don't forget the space at the end) + the value returned from the 'Login' endpoint that you copied in step 4.
8. Click "Authorize"
9. Run the 'Protected' endpoint

Convention Customisation

Although the default conventions are good enough for most cases, you can customise them.

IWebApiOpenApiVersionConfigurationService

This is used to get the OpenApiInfo for each WebApiEndpointVersion.

serviceCollection.AddWebApiEndpointOpenApiVersionConfigurationService<WebApiOpenApiVersionConfigurationService>();

IWebApiOpenApiVersionUIConfigurationService

This is used to configure the OpenApi JSON endpoint for each WebApiEndpointVersion.

serviceCollection.AddWebApiEndpointOpenApiVersionUIConfigurationService<WebApiOpenApiVersionUIConfigurationService>();

IWebApiVersionConfigurationService

This is used to configure ApiVersioning and ApiExplorer.

There is an overload of AddWebApiEndpoints that takes a generic type of IWebApiVersionConfigurationService.

builder.Services.AddWebApiEndpoints<CustomWebApiVersionConfigurationService>();

Use this instead

builder.Services.AddWebApiEndpoints();

Roslyn Analysers

• FWAEM0001 - Non empty constructor found on WebApiEndpoint
• FWAEM0002 - BadRequest without 'ProblemDetails' use found on WebApiEndpoint