Add the proposed Port Attributes API for python testing

[eleanorjboyd]

fixes #22021.

@alexr00, we are not able to provide a pattern for the extension like @paulacamargo25 was doing for debugpy and we are not able to define a port range. Is there something else I should be putting into the PortAttributesSelector?

[eleanorjboyd]

@karthiknadig was package-lock supposed to be updated after I edited package.json for this change? Ran npm ci and nothing happened.

[alexr00]

@alexr00, we are not able to provide a pattern for the extension like @paulacamargo25 was doing for debugpy and we are not able to define a port range. Is there something else I should be putting into the PortAttributesSelector?

Is there anything distinct about the port you care about here? We can expand the API to have other properties.

[alexr00]

This will cause every single port to be ignored, which essentially turns off auto port forwarding for all ports.
If you are trying to create a no-op implementation, then you should return undefined.

[karthiknadig]

We create two ports while doing test discovery and running tests. One of them stays open till user closes VS Code, the other one is transient.

Both are created using net.Server : https://nodejs.org/api/net.html#serverlistenport-host-backlog-callback

Is there a way we can push this info into the provider? i.e., whenever we open a port could we do something like setPortAttributes(port: number|range, attribute: PortAutoForwardAction) for those ports, and when we close the server, we could resetPortAttributes(port: number|range).

[karthiknadig]

The other option is, to return undefined until such a port is created, then we update internal state inside TestPortAttributesProvider with the updated list of ports that we hold active.

[alexr00]

It sounds like we have 2 problesm:

1. You don't have enough information at registration time to provide a good PortAttributesSelector.
2. You can't tell which port is yours based on the properties passed into providePortAttributes.

For problem 1 (and actually problem 2 too): are you able to simply wait to call registerPortAttributesProvider until you've started your process and know the port number? So long as you do the registerPortAttributesProvider in the same frame as you start the process, you will be registered in time. This would also solve problem 2, as you could pass your port number or pid into your PortAttributesProvider.

[eleanorjboyd]

were able to call registerPortAttributesProvider at the time of creation of the port number so this should resolve that problem!

[alexr00]

The setPortAttribute and resetPortAttribute functions look good for solving problem 2!

[alexr00]

Passing {} is still not ideal for the selector. This means that your attributes provider will be called for each auto forwarded port. Is there really no commandPattern that you can specify that will at least filter out some ports?

[alexr00]

I was thinking of requiring that at least one value of the selector is set to a meaningful value and logging an error if it's not set properly.

[eleanorjboyd]

@karthiknadig, thoughts on this? I am not sure about the specific of the commandPattern.

[karthiknadig]

The port is created in the extension host, so the process itself is whatever process that extension host is running in. So we could specify the process id of the extension host.

[alexr00]

The setPortAttribute and resetPortAttribute functions look good for solving problem 2!

[eleanorjboyd]

closing as we are moving to using named pipes as a fix for some other issues and therefore will no longer be using ports that should be registered. Thanks!

vscode-python/src/client/common/process/rawProcessApis.ts

Line 226 in f6e1338

const proc = spawn(file, args, spawnOptions);