PgTap, unit test a foreign key is deferrable

Question

I am using PgTap to unit test a Postgres (v9.4) database structure in a continuous migration process. It works great.

Here is my question: « Is there a way to control that a foreign key constraint is deferrable (initially immediate) ? »

I do already check foreign keys but I want to ensure some of them are deferrable.

Thank you for your help.

Answer 1

Ok, it appears there are no methods to test such thing with PgTap for now so I ended up with

SELECT results_eq(
    $$select condeferrable, condeferred from pg_catalog.pg_constraint where conname = 'default_article_id_fk'$$,
    $$values ('t'::bool, 'f'::bool)$$,
    '"default_article_id_fk" is deferrable initially immediate.'
);

That does the job.