Confusing Debug type dropdown behavior

[gregvanl]

• VSCode Version: 1.19.2
• OS Version: Windows 10

The Debug configuration dropdown shows unsupported debug types (Python, Java) for Node.js apps.

Steps to Reproduce:

1. Install the Python Extension Pack which includes the Python debugger.
2. Start a debug session on an Node.js app without a launch.json (for example a new Express app)

You will not see the Debug type dropdown and the session is started using the in-memory Node.js launch configuration.

3. Now install the Chrome debugger.
4. Start a new debug session for the Node.js app.

You now see the Debug type dropdown listing: Node.js, Python, Chrome.
My guess is that now that there are two possible Node.js debuggers (Node.js and Chrome), the dropdown is shown. I don't think it should show Python since it isn't appropriate. You can also reproduce this with the Java Debug extension, if installed it is also in the dropdown but only if the Chrome debugger is installed.

5. Uninstall the Chrome debugger and the dropdown is not shown.

If VS Code can determine that the debugger isn't the correct type, we should filter it out of the list. This behavior is also confusing as I didn't understand why sometimes the dropdown was displayed when I had multiple debuggers installed and sometimes not.

[gregvanl]

This is problematic if the user selects the wrong Debug type as some extensions (C++, Python) write out a launch.json to the workspace rather than just use an in-memory version like the Node.js debugger.