Hello, thanks for this project, I was looking for something exactly like it.
It might be I'm unfamiliar with hyperfiddle tests, but I don't understand why the tests in #72 and #73 pass by default (with the green check mark). Other problems behave as expected -- they fail first, and then pass after fixing the (def __ ....).
To reproduce, open the project in Emacs/CIDER, load #72, make sure tests are enabled with (hyperfiddle.rcf/enable!), and evaluate the test. It returns 11 with a green check.