I'd still advocate for using randomly generated string. We've already ran into this where tests are failing because a previous test defined a value which clobbered up the expected results for a next/unrelated unit test. For a case in point, [one of the changes in this PR](https://github.com/oaeproject/Hilary/pull/698#discussion-diff-7954144L672) is fixing an issue like this.

It's not standard practice, because most of our tests can't run into situations like this.