How can I start debugging R or Python code using the same key in Visual Studio Code? - visual-studio-code

Question

Trying to avoid the XY problem, my problem at the very high level: I work in a VS Code workspace with R and Python code files, and I often need to debug one or the other. Currently I have different debug launch configurations saved, and I need to switch between them manually - that is a pain. I would like to use F5 to
launch the Python debugger when the editor is active in a .py file
launch the R debugger when the editor is active in a .R file
I see many technical ways of doing that, but all have their roadblocks (some of which may just poor documentation):
Create my own extension with a dynamic debug configuration that determines the type of the active editor and starts the correct debug configuration. (A lot of effort required.)
Use a "compound" launch configuration, starting both R and Python launch configurations, and stopping all but one. This can be done using a "prelaunchTask" for each, but non-zero return codes create error message that I don't like.
Use editor-dependent key mappings ("when": "editorLangId == 'python'"), but which command for debugging to start and how to pass the launch configuration? There is vscode.startDebug which takes arguments (https://github.com/microsoft/vscode/issues/4615), but I cannot keybind to that. And then there is workbench.action.debug.start which seems to ignore arguments. And then there is vscode.commands.executeCommand to which I cannot keybind, either.
Use a multi-command extension to bind a key to something like "set debug configuration, then press F5". But how to do that?
Etc. etc.

Answer 1

After much fiddling, here is one solution following idea 2:
settings.json (launch configs could be put into launch.json):
{
"debug.onTaskErrors": "abort",
"launch": {
"compounds": [
{
"name": "Python/R: Current File",
"configurations": [
"Python: Current File",
"R: Current File",
],
},
],
"configurations": [
{
"name": "Python: Current File",
"type": "python",
"preLaunchTask": "check_ext py",
"request": "launch",
// ...
},
{
"name": "R: Current File",
"type": "R-Debugger",
"preLaunchTask": "check_ext R",
"request": "launch",
// ...
}
],
},
}
tasks.json:
{
"version": "2.0.0",
"tasks": [
{
"label": "check_ext py",
"type": "shell",
"command": "echo ${fileExtname} | grep -i ^.py$",
},
{
"label": "check_ext R",
"type": "shell",
"command": "echo ${fileExtname} | grep -i '^.R$'",
},
],
}