launchDirectory is incorrect in multi-root workspace

[bersbersbers]

Describe the bug
In a multi-root workspace, the launch directory is incorrect. I think this is two issues at once:

1. The value set in the launch config is overwritten. (I am not sure why that is, but I also checked hard-coded literals in the debug config, and they never become effective.)
2. It is overwritten with an incorrect value. This is due to
   

   VSCode-R-Debugger/src/debugRuntime.ts

   Line 112 in 075bee3

   rStartupArguments.cwd ||= vscode.workspace.workspaceFolders?.[0].uri.fsPath;

   
   (I feel it should be overwritten with the file's workspace folder, workspace.getWorkspaceFolder(uri), see https://github.com/microsoft/vscode/wiki/Adopting-Multi-Root-Workspace-APIs#eliminating-rootpath)

To Reproduce

D:\>tree /f R
Folder PATH listing for volume Data
D:\R
│   R.code-workspace
│
├───R1
│       .Rprofile
│
└───R2
    │   .Rprofile
    │   code.R
    │
    └───.vscode
            launch.json
            tasks.json

D:\>more R\R.code-workspace
{
    "folders": [
        {
            "path": "R1"
        },
        {
            "path": "R2"
        }
    ]
}

D:\>more R\R1\.Rprofile
i_am <- "R1"

D:\>more R\R2\.Rprofile
i_am <- "R2"

D:\>more R\R2\code.R
print(i_am)

D:\>more R\R2\.vscode\launch.json
{
    "version": "0.2.0",
    "configurations": [
        {
            "type": "R-Debugger",
            "name": "Debug R-File",
            "request": "launch",
            "debugMode": "file",
            "launchDirectory": "${workspaceFolder}",
            "workingDirectory": "${workspaceFolder}",
            "file": "${file}",
        }
    ]
}

D:\>more R\R2\.vscode\tasks.json
{
    "version": "2.0.0",
    "tasks": [
        {
            "label": "show $workspaceFolder",
            "type": "shell",
            "command": "echo ${workspaceFolder}",
            "problemMatcher": []
        }
    ]
}

code R\R.code-workspace R\R2\code.R

Then start debugging using "Debug R-File (R2)".

Expected behavior
"R2" in the Debug Console

Actual behavior
"R1" in the Debug Console

In the output, one can see

[info....] [10:04:30.630] [ ] R Startup:
[info....] [10:04:30.630] [ ] {"path":"\"C:\\Program Files\\R\\R-4.1.2\\bin\\R.exe\"","args":["--quiet","--no-save","--ess"],"cwd":"d:\\R\\R1"}

Desktop (please complete the following information):

• OS: Windows and Linux
• R Version: 4.1.2
• vscDebugger Version: 0.4.7
• vscode-r-debugger Version: v0.4.7

[renkun-ken]

Maybe https://github.com/REditorSupport/vscode-R/blob/master/src/util.ts#L149 could be useful?

[bersbersbers]

I guess so, yes. I just wonder if vscode.window.activeTextEditor is a good choice - the debug launch config does does not necessarily have anything to do with the currently open file.

[renkun-ken]

Yes, it should be adjusted for the purpose of debugging.