How to programmatically launch a .NET 6 minimal API with no Startup class

Question

I am trying to implement PactNet contract tests on our provider project. However the issue is that we are using a Minimal API so instead of having a Startup.cs and Program.cs class we just have it all rolled into one Program.cs.

This poses an issue, as previously I would have been able to run Host.CreateDefaultBuilder and pass it the Startup class, as demonstrated in the PactNet samples. All the examples of doing something similar that I've run across on SO use TestServer or WebApplicationFactory, which are inapplicable in this scenario since they start an in-memory server, and I need a server running on a real TCP socket, so that PactNets Rust internals can communicate with it.

The only solution I've managed to find is to just manually run the provider with dotnet run however this feels hackish, and I would much prefer to do it programmatically as previously was possible with Host.CreateDefaultBuilder.

Answer 1

Things you can try:

• Switching back to the generic hosting (see for example this answer).

• Switching from top-level statements to "standard" Main entrypoint - declare a class with static Main method and move everything into it (for example in the same Program.cs file) and call this Program.Main instead of old setup (note that this will greatly reduce customizability of the starting server):

public class Program
{
    public static void Main(string[] args)
    {
        // ... everything from your Program.cs
    }
}

• Extracting parts of the top-level statements file into methods and calling them on manually created builder (almost the same as keeping Startup file and calling it's methods on appropriate parts of builder and app in the new setup).