The template test database should be immutable during the tests. Just clone the template database, and run tests against the clone. When done, drop the clone.
Is it significantly faster than importing from prepared `*.sql` files? The problem here is that, as I understand, we will have to restart the application every time so that it connects to the new data base. It takes about a second. I was hoping that there is some way to clone a single schema, but I figure it is not possible. So now I have to either drop the schema and import it again from `*.sql`, or drop the data base, clone it from the template and restart the application. It does not seem like a clear win. Note that I need the application to be running so that I may observe the HTTP API. Although perhaps I can factor the API out and write a simple wrapper for it that would start faster. But this is extra work and it would increase the complexity of the project, so I am not sure if I should.