vscode + chrome debug plugin + parcel

launch.json

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "type": "chrome",
            "request": "launch",
            "name": "Launch Chrome against localhost",
            "url": "http://localhost:1234",
            "webRoot": "${workspaceFolder}",
            "trace": true,
            "breakOnLoad": true,
            "sourceMapPathOverrides": {
                "*": "${webRoot}/build/*"
            }
        }
    ]
}

package.json

{
  "scripts": {
    "demo04": "parcel examples/demo/index.html --no-hmr --port 1234 --out-dir build",
  }
}