Debugging current file in VS Code

Change to:

"program": "${file}"

For reference this is the full launch.json

{
  "launch": {
    "version": "0.2.0",
    "configurations": [
      {
        "name": "Node.js - Debug Current File",
        "type": "node",
        "request": "launch",
        "program": "${file}"
      }
    ]
  }
}

For a single file, you can skip the launch.json file entirely. Just click the green arrow in the debugger panel and choose Node as your environment.

From here.