I began working on an .Net Core solution in VS 2015, which contains an ASP.Net Core project and a couple of .Net Core class libraries. The solution was under TFS source control.
I wanted to include some unit tests. Since .Net Core unit test project templates are not included with VS 2015, I decided to install VS 2017 and upgrade the solution. After upgrading, I was able to add a unit test project and everything compiles and runs normally.
When I first opened the solution after upgrading, though, I initially got an error about the solution being treated as though it was not under source control. Based on Google searches, I went into File -> Source Control -> Advanced -> Change Source Control and clicked "Bind" on each project. The three old projects link right up and show up as "Valid", while the solution file and the new unit test project show up as "Invalid". Unbinding, unloading, reloading, and rebinding the invalid project did not help. I can force the project to bind even though it is invalid (against Visual Studio's warnings), and after some tinkering, I can get the solution to check in, but when I get latest on another machine, the three original projects say "Not Available" and the unit test project is not visible.
Other symptoms: project.json is not found when I try to check in (I have to "undo" or "exclude" to check the solution in) and regardless of what I try, the invalid unit test project's folder shows up in the root folder of the directory tree (at the same level as "src" and "Backup") while the valid projects are in the "src" directory. I am inferring this is because the new solution types allow an .xproj file, while the old solutions required project.json, but I don't know what to do about it...
Any ideas on how to relink this to source control would be appreciated! I did not upgrade TFS server when I upgraded VS, but I don't directly have access to it, so hopefully this is not a requirement...