Routing in ASP.NET Core without a 'slash'

Yes, it is possible.

I tested on ASP.NET Core 2.2.

TestController.cs:

[Route("test")]
public class TestController :Controller
{
    [HttpGet("somepath/{a},{b},{c}")]
    public IActionResult Test(string a, string b, int c)
    {
        return Ok($"a: {a}, b: {b}, c: {c}");
    }
}

StartUp.cs:

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc();
    }

    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        app.UseMvc();
    }
}

Program.cs:

public class Program
{
    public static void Main(string[] args)
    {
        CreateWebHostBuilder(args).Build().Run();
    }

    public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .UseStartup<Startup>();
}

When opening http://localhost:5000/test/somepath/abc,def,123 I get the expected output:

a: abc, b: def, c: 123