I have opened Angular application from locally mapped TFS path using VS Code. When I make some changes in application files, changes are not reflecting in TFS. (i.e.., Files are not checked-out.) When I select, check-in pending changes, it shows 'no pending changes'.
Do I need to modify/configure any other settings?
First, make sure you have installed and configured Visual Studio Code and the integration of TFVC properly. Detail steps please refer my answer in this link.
According to your description, please also double check your workspace's configuration if you are using local workspace or not.
A local workspace does automatic detection of changed files. A server workspace requires explicit check out/in to notify the server of pending changes.
