Minimal API endpoints do not appear in OpenAPI if WithGroupName() is used

[martincostello]

Describe the bug

If WithGroupName(string) is used with a Minimal APIs endpoint, it disappears from being displayed in OpenAPI.

Using WithGroupName()

No WithGroupName()

To Reproduce

Create an empty ASP.NET Core 6 project with a reference to Swashbuckle.AspNetCore with the below code as Program.cs.

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen(options =>
{
    options.SwaggerDoc("v1", new() { Title = builder.Environment.ApplicationName, Version = "v1" });
});

var app = builder.Build();

app.MapGet("/greeting", () => "Hello, world")
   .WithGroupName("Greetings");

app.UseSwagger();
app.UseSwaggerUI(options =>
{
    options.EnableTryItOutByDefault();
    options.SwaggerEndpoint("/swagger/v1/swagger.json", $"{builder.Environment.ApplicationName} v1");
});

app.Run();

Further technical details

.NET SDK version 6.0.100-rc.1.21460.8

[captainsafia]

Thanks for testing these scenarios, @martincostello!

So, the GroupName metadata is designed to be used when generating multiple Swagger documents. So the following:

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen(options =>
{
    options.SwaggerDoc("v1", new() { Title = $"{builder.Environment.ApplicationName} v1", Version = "v1" });
    options.SwaggerDoc("v2", new() { Title = $"{builder.Environment.ApplicationName} v2", Version = "v2" });
});

var app = builder.Build();

app.MapGet("/greeting", () => "Hello, world")
   .WithGroupName("v1");

app.MapGet("/farewell", () => "Bye, world")
   .WithGroupName("v2");

app.UseSwagger();
app.UseSwaggerUI(options =>
{
    options.EnableTryItOutByDefault();
    options.SwaggerEndpoint("/swagger/v1/swagger.json", $"{builder.Environment.ApplicationName} v1");
    options.SwaggerEndpoint("/swagger/v2/swagger.json", $"{builder.Environment.ApplicationName} v2");
});

app.Run();

Should work to display the /greeting API under the v1 subsection and the /farewell API under the v2 subsection.

WithTags should work for grouping endpoints within a document.

[martincostello]

Ah, fair enough, my mistake!

I guess the nomenclature in this case is slightly confusing, but I'd probably have ended up doing the right thing via trial-and-error if the version I was using had WithTags() 👍

[captainsafia]

@martincostello No worries! BTW, I misspoke. The WithTags stuff doesn't totally work yet. You'll need to use the changes in domaindrivendev/Swashbuckle.AspNetCore#2210 to get it working in the E2E.

Closing this one for now.