VSCode Debugging - Opening Files on launch

I am new to VSCode and I implemented a vscode extension. I started to write tests using runTests from vscode-tests.

To Debug I wrote this configuration:

"name": "Test Syntax Coloring",
"type": "extensionHost",
"request": "launch",
"runtimeExecutable": "${execPath}",
"args": [
    "--extensionDevelopmentPath=${workspaceFolder}",
    "--extensionTestsPath=${workspaceFolder}/out/tests/suite/index"
],
"outFiles": [
    "${workspaceFolder}/out/tests/**/*.js"

I searched for an ability to open a file on launch, but I couldn't find a way to do so. Is it possible? How?