This commit adds documentation and tests for the clusterIndexFor helper,
making it easier to understand what it does and how to use it safely.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit restructures seekPosition from a complex state-manipulating
loop into a simple loop of iteratively applying an increment operation
to the combinedPos. The increment operation itself is now tested, and
much easier to understand.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>