I wonder if it would work do design something that was able to say

    test 1: 
       do step 1, assert step 1

    test 2:
       requires: test 1
       do step 2, assert step 2

    test 3:
       requires: test 2
       do step 3, assert step 3

    test 4:
       requires: test 2
       do step 3, assert step 3

If the assertion of each test doesn't change any state, that might make things easier to read. Though, given that I haven't spent much time pondering it, I expect it could have it's own problems.

But it could also do things like skip test 3 if tests 2 or 1 failed - because it knows about the relationship.