First make sure .shadow-cljs doesn't exist. Then run:

clj -A:shadow watch tests

Point your browser to http://localhost:7711/. All tests should be passing.

Then, stop the watch, and then start it again:

clj -A:shadow watch tests

Go back to http://localhost:7711/. The tests should still be passing.

Now go to src/app/core_test.cljs and save the file. The tests should rebuild and the tests page should run again, but this time the tests will fail.