How does one keep track of features on branches in CI?

If one has a bunch of implemented features on the develop branch, how does one keep track of the new features getting merged onto staging/master, potentially requiring testing? Does one look at the commit history? Do software development teams have spreadsheets of the features currently on each branch? Or is there usually mapping between issues (/tasks/tickets), with descriptions of implemented features and branches?

I’m basically looking for a way to ensure that only fully tested and approved features are deployed to master.