Allow extensions to modify terminal environment variables

[DanTup]

Users sometimes want to set SDK paths local to their project to pin the versions of them (or to progressively move projects to the next version). There are two places where they'd want these paths to apply:

1. The extension uses it to load the correct SDK (eg. for language services, debugger, etc.)
2. In the integrated terminal

Currently it doesn't seem like there's a way to provide a path once to be used for both of these purposes so the user has to set the path in two places (one in extensions settings and the other in terminal path) and keep them in sync.

I thought maybe I could read the terminals path and use that when locating my SDK, but I tried this:

{
  "terminal.integrated.env.windows": {
    "PATH": "${env:PATH};C:\bin"
  }
}

However if I read that value from "terminal.integrated.env.windows" I get the literal string above without the ${env:PATH} being resolved. Although I could resolve that myself as a special case, maybe there's a better way to handle this (like allowing the user to specify paths that will be prepended to the terminal paths that extensions could use too).

[Tyriar]

@sandy081 is there a way to read settings in the API and then resolve the variables inside them?

[sandy081]

@Tyriar Following is the API to read configurations

vscode.workspace.getConfiguation()

But I do not think there is an API to resolve variables.

@isidorn might have an idea?

[isidorn]

@DanTup @sandy081 there is no extension API to resolve variables
We do not support variables resolving in settings inside vscode (there is a seperate feature request). Dut to the above it is not possible to read settings in the API and resolve variables

[DanTup]

My request here is not specifically about resolving variables, but rather about providing some solution to this problem. I don't think reading from the terminal path as suggested above is the best one. However, I do think it'd be good to provide some way for a user to be able to specify folder-level paths that would apply to in-built terminals and be readable by extensions to allow projects to be pinned to specific versions of SDKs/cli tools.