Non default database name causing errors for some sql commands

[em-c-rod]

Entering the container for reference:
inspec shell -t docker://test_postgres --input-file ./crunchy-data-postgresql-stig-baseline/inputs_postgres14_example.yml

Error: Querying pgaudit.log_level without specifying the database name (this is what is written in the InSpec control V-233512):

sql.query('show pgaudit.log_level')

@desc="PostgreSQL query with error: show pgaudit.log_level",
@output="\npsql: error: connection to server at \"localhost\" (::1), port 5432 failed: FATAL:  database \"testuser\" does not exist\n">

Success: Querying pgaudit.log_level with specifying the database name:

sql.query('show pgaudit.log_level', [input('pg_db')])
@desc="PostgreSQL query: show pgaudit.log_level", @output="log"

cobbling some stuff together and using this bitnami image that has pgaudit installed by default:
docker run -it --name postgres-audit -e ALLOW_EMPTY_PASSWORD=yes -e POSTGRESQL_PGAUDIT_LOG=ALL docker.io/bitnami/postgresql:15
spins up postgres and enables pgaudit (see the line in the console saying 'pgaudit extension initialized')
$ docker exec -it postgres-audit psql -U postgres -A -t -c "SHOW pgaudit.log_level;"
log
runs that query of yours and returns a value without crashing like yours did
the line i'm running i actually pulled from this similar control from some vmware stig: https://www.stigviewer.com/stig/vmware_vsphere_8.0_vcenter_appliance_postgresql/2023-10-29/finding/V-259169 - the flags are basically just formatting things but you can look at it yourself if you want
the key thing to note i think is that i'm coming in as the postgres user and there is a postgres db created by default in the instance
$ docker exec -it postgres-audit psql -U postgres -A -t -c "\l"
postgres|postgres|UTF8|en_US.UTF-8|en_US.UTF-8||libc|
template0|postgres|UTF8|en_US.UTF-8|en_US.UTF-8||libc|=c/postgres
postgres=CTc/postgres
template1|postgres|UTF8|en_US.UTF-8|en_US.UTF-8||libc|=c/postgres
postgres=CTc/postgres
i think you are coming in as testuser and are not explicitly setting a database in which you are doing this. looking at the docs, i think if you don't explicitly provide a database name then it uses the username as the name of the database: see "Usage" section here near the end of that first paragraph: https://www.postgresql.org/docs/15/app-psql.html. and then as the error states, since there is no database containing the name testuser it blows up.
resolution would probably be to just provide the database name