How to configure AppHost for integration tests?

[impworks]

I have an application that uses PostgreSQL.
When I am developing it locally, I use WithDataVolume to store data between sessions.
In the integration tests, however, I need to start with an empty volume each time to ensure test isolation.
Right now I am using the console app arguments to pass a special flag:

Integration Test:

var appHost = await DistributedApplicationTestingBuilder.CreateAsync<Projects.MyApp_AspireHost>(["--integration-test"]);

AppHost/Program.cs:

var builder = DistributedApplication.CreateBuilder(args);
var isIntegrationTest = args.Any(x => x == "--integration-test");
var pgsql = builder.AddPostgres("postgres");

if(!isIntegrationTest)
    pgsql.WithDataVolume();

var db = pgsql.AddDatabase("mydb");

This approach works, but feels like a dirty hack to me, which may have downsides or consequences of which I am not aware.
Is there a proper way to achieve this?

[davidfowl]

@ReubenBond should we set a first class flag for when the application has been booted with the DistributedApplicationTestingBuilder? I've seen this a couple of times.

cc @mitchdenny

[mitchdenny]

@impworks we do actually support the concept of customizing resources for deployment. Postgres is a good example:

var db = builder.AddPostgres("pg")
                .PublishAsAzurePostgresFlexibleServer()

For local development we'll use Postgres in a docker container locally, but if you deployed to say Azure using azd then we'd deploy using the Azure-managed service. Its possible to extend the model for other cloud providers as well (AWS is already working on their extensions).

[davidfowl]

I think the meta point here is that we need to set something to indicate that we're running from a test and that developers can use in their app host to write conditional logic (like we have for publish and run).

[KennethHoff]

Why not just do that; add a third option, "publish", "run", "test"

[davidfowl]

We could.

[Poppyto]

We changed the settings.EnvironmentName in DistributedApplicationTestingBuilder.CreateAsync like this :

   var appHost = await DistributedApplicationTestingBuilder.CreateAsync<Projects.XXXXt>([], (action, settings)=>
   {                
       settings.EnvironmentName = "Integration";
   });

In the AppHost project, we add a appSettings.Integration.json configuration file to handle the mounting volume or not with the help of builder.Configuration.
It felt less hacky than passing args.