For SERVER-61137 I added tenant_migration_rollback_to_stable.js:

https://github.com/10gen/mongo/commit/a0ca381d51c085a0ba3299b2086ae7663cc29f45

In that commit I made a hack, the JS test puts some WT files in /tmp/tenant_migration_test_data, and mongod's code is updated to check for files there. If it finds them, it does a rollback-to-stable operation on them, and the JS test checks for certain log messages. This was a good way to test some new C++ code before the whole PM-2353 is implemented. But it's a problem if the same host is used to run multiple tests: if one test runner executes tenant_migration_rollback_to_stable.js and modifies the files in the tmp dir, while another unrelated test runs, then since mongod always checks the tmp dir for files to import, the two tests will read/write files in the tmp dir at once and a crash is likely.