Honest question: why would CI only run a single unit test?

Well, if you're currently writing one unit test, and want to test that test...

Why wouldn’t you use your development medicine? “…”

lol "medicine"... damn phone. I meant "machine" of course.

You are advising application developers against using their chosen database optimally? I think it is not needed, I rarely see an application change its database.

While I agree, it's amusing to see this comment in a thread about an application providing a new database, and where one of the main reservations is around people needing to change the DB.

> WordPress developers who do not agree with the idea of introducing SQLite in WordPress core are mainly concerned about ... migration process or converting from one database to another

Tight coupling is bad, haven't you heard?

I don't know if all the blame goes to postgres or not, but a unit test in Rails is typically what others would call an integration test and Rails' architecture is more to blame than SQL. If someone chooses to use postgres in their application, don't be surprised when you see code that uses postgres. Wanting to force others to make applications that work with the lowest-common denominator of SQL could make one appear naive, and that you might not have ever faced the same problems others developers have faced.

> Apps and frameworks should work with the lowest-common denominator of SQL.

Pointless limitation that will make your app slower and SQL code worse.

> I get physically ill when I walk into yet another Rails shop to find that they have used every cool feature of Postgres and as a result, the CI must spin up a huge postgres instance and multiple plugins just to run a single unit test. Ugh.

shrug. We (not rails shop) just create temporary database, pass it to CI test, remove after. Picking database because your CI is done badly is like one of the worst ways to decide on architecture

shrug. a lot of systems have been in place long before modern CI

Assuming they can just "do it" is a bad assumption of both the depth of their existing stack and their companies budget for migrating.

I'm gonna guess you haven't been around long enough to have FTP'd files as a deployment.

> Pointless limitation that will make your app slower and SQL code worse

That seems to be the common opinion, but I don't think that it's based on anything tangible.