Add Executable launch profile support to dotnet run and dotnet watch

[Copilot]

Refactors launch profile parsing and adds support for Executable command name.
Fixes environment variable expansion and adds tests.

[baronfel]

@copilot Good initial attempt, but we can clean this up some. Please address my review comments.

[baronfel]

@dotnet/dotnet-testing if we expand the 'launch settings' handlers that are known, how should the testing experience react? does test support launch settings profiles today?

[Evangelink]

@baronfel I just read in diagonal the PR. I think it'd be great to ensure that's also working for test verb.

cc @Youssef1313

[tmat]

@Evangelink @Youssef1313

What should dotnet test do if the profile is Executable?

For example, if I specify:

{
    "profiles": {
        "Execute": {
            "commandName": "Executable",
            "executablePath": "dotnet",
            "commandLineArgs": "--version"
        }
    }
}

Should it just run dotnet --version? Doesn't seem very useful.

[Evangelink]

@Evangelink @Youssef1313

What should dotnet test do if the profile is Executable?

For example, if I specify:

{
    "profiles": {
        "Execute": {
            "commandName": "Executable",
            "executablePath": "dotnet",
            "commandLineArgs": "--version"
        }
    }
}

Should it just run dotnet --version? Doesn't seem very useful.

I think the same question applies for dotnet run or dotnet watch. For me, dotnet test is equivalent to dotnet run sln (I know it's not supported, it's just to give a high level parallel for features support).

Now, this being said, I agree that if you do "conflicting" queries that can lead to be situations and I don't know what should be the proper UX here. I still tend to think I'd prefer to have something (good or bad) similar to dotnet run as much as possible.

[tmat]

The difference is that dotnet test passes various test related command line args when launching project. Should those be ignored?

See https://github.com/dotnet/sdk/blob/main/src/Cli/dotnet/Commands/Test/MTP/TestApplication.cs#L88