You're hitting on the difference between unit tests and integration tests. Unit tests should generally not try to test load limits or timing, while integration tests should have the freedom to load millions of rows into a table and verify it doesn't take too long to query the table. Unit tests should be quick enough to run before every commit, while integration tests run on a shared server with enough resources to exercise limits. Most interesting projects need both unit and integration tests.
Yes, but the original discussion was declarative vs imperative, and tests were introduced only as an analogy by gp. I just showed that it doesn’t really apply, it was not a question on how to test in general.
