Add existing item doesn't add to source control


Create new Node.js console app
Right click on project in solution explorer, Add Solution to Source Control
You should see all items in solution explorer get a + icon overlay
Outside of VS, create a newfile.js in the project folder
In VS, Add existing Item newfile.js, or Include in Project

The item is added to the project, but there's no + icon overlay ie. it's not added to source control.

If you do the same in C# project, it gets added to source control.

PTVS has the same issue.