It turns out i have been **years** doing this wrong: you are supposed to
pass that value as a text, like 'CURRENT_TIMESTAMP', not like the
keyword so that it returns the current timestamp as a timestamptz.
However, i have been doing it wrong because of a bug in previous
versions of pgTAP[0], that did not take into account keywords such as
CURRENT_TIMESTAMP or CURRENT_DATE and was comparing their actual values,
not the names, therefore i thought that i misread the documentation.
Only now have discovered this because Debian 12 upgraded pgTAP version
to 1.2.0.
[0]: https://github.com/theory/pgtap/issues/244
jordi fita mas