Making the dbt-devnull adapter flexible for more DB types

[jice-lavocat]

Currently DevNullAdapter inherits from SQLAdapter.

This introduces several specific behaviors that will lead to unexpected parsing effects when using linters such as SQLFluff.
For instance, the {{ source(a,b) }} or {{ ref(a) }} method use some specific quotes in BigQuery (instead of " it should be using `).
This results in SQLFuff returning failures similar to Found unparsable section: ...

--

One solution I've been using, but which requires having a fork was to change the impl.py file from

from dbt.adapters.sql import SQLAdapter
from dbt.adapters.devnull import DevNullConnectionManager
from dbt.adapters.base.relation import BaseRelation

class DevNullAdapter(SQLAdapter):
    ConnectionManager = DevNullConnectionManager
...

to

from dbt.adapters.bigquery import BigQueryAdapter
from dbt.adapters.devnull import DevNullConnectionManager
from dbt.adapters.base.relation import BaseRelation

class DevNullAdapter(BigQueryAdapter):
    ConnectionManager = DevNullConnectionManager
...

I'm pretty sure that there could be a better way to make the devnull adapter more flexible but I'm not a dev guy, so I can't really suggest better.

[jice-lavocat]

Could there be an option sent from the profile.yml file to the adapter that specifies the parent?

[bachng2017]

thank you very much for the comment.
We do not have a env. to test BQ. If you could provide a branch that works for you, then we could test that code on our side and merge.

[bachng2017]

ah, sorry, you've already forked and tested on your side already right ?
if you could provide a MR we will check
thanks a lot