vscode-extension-samples/task-provider-sample/.vscode/tasks.json

{
	// See https://go.microsoft.com/fwlink/?LinkId=733558
	// for the documentation about the tasks.json format
	"version": "2.0.0",
	"tasks": [
		{
			"type": "npm",
			"script": "compile",
			"isBackground": true,
			"problemMatcher": [
				"$tsc-watch"
			]
		}
	]
}