Fix #147912 (multipleSessionWarning debug option)

[dirondin]

Add new launch config debug option for silent '{0}' is already running. Do you want to start another instance? confirm dialog.

Tested with simple launch config:

{
    "command": "npm start",
    "name": "Run npm start",
    "request": "launch",
    "type": "node-terminal",
    "multipleSessionWarning": false
}

This PR fixes #147912

[dirondin]

Can anyone review this PR or provide feedback? :)

[roblourens]

Sorry for letting this slip through the cracks. I guess having this as a launch config option, rather than a user/workspace setting makes sense since there might be a particular launch config that you want to start multiple times?

I will take a look at this next week for July.

[dirondin]

It might make sense to make this option through the user/workspace setting 🤔
Also will be grate enabled this option (always launch or always don't launch) directly from confirm dialog (like "[ ] Remember my choice").
Maybe I will make this option next weekend 👍

[roblourens]

Not sure about the checkbox, where we have options like that it usually stores it in some hidden state and does not write to a launch config

[dirondin]

Yes. The checkbox is an option for user/workspace or "hidden" location settings, not a launch configuration property. I just said that I would try to explore this option as well (in another PR).

[roblourens]

Feel free to explore it, but I'm not sure how I feel about that option, would take some thinking

[roblourens]

Thoughts @isidorn?

[roblourens]

This looks good, but I'm out of the office and will merge it for August.

[isidorn]

@roblourens I am not a biggest fan of adding these "UI" settings to the launch.json. A better approach would probably be a setting. And yes I know that then it is not launch config specific, but I am worried if we keep it in a launch.json nobody will find it.

So a dialog + checkbox that writes to a setting is the way to go imho.
Rule of thumb - avoid UI attributes in launch configurations.

[roblourens]

To me, it's similar to the presentation section, which also sets metadata on how vscode should present/handle the launch config. I think that per-launch config makes the most sense, because starting multiple sessions of the same config is actually annoying, and I only want to avoid it for some specific configs.