Pinning a file would be a useful option, too. My use-case is MSpec where each "context" is in a separate class and individual "specifications" (tests) are fields ("It" delegates) in the class. Related tests are most commonly grouped together in a single file containing multiple context classes. In that situation, pinning a class is essentially not much different to pinning a single test. The next level "up" is the file, so to pin a related set of tests one needs to pin the file. Namespace would be the next level up the hierarchy from that, but the file is normally the area of focus and would be the most natural thing to pin.
Pinning a file would be a useful option, too. My use-case is MSpec where each "context" is in a separate class and individual "specifications" (tests) are fields ("It" delegates) in the class. Related tests are most commonly grouped together in a single file containing multiple context classes. In that situation, pinning a class is essentially not much different to pinning a single test. The next level "up" is the file, so to pin a related set of tests one needs to pin the file. Namespace would be the next level up the hierarchy from that, but the file is normally the area of focus and would be the most natural thing to pin.