How to configure PostgreSQL's test database before testing?

My website uses PostgreSQL and its full-text search. For that to work, I
need to execute some configuration queries in order to configure some
full-text search extensions.

This is what I have written in my seeds.rb file to configure the
development database:

ActiveRecord::Base.connection.execute(“CREATE EXTENSION unaccent;”)
ActiveRecord::Base.connection.execute(“ALTER TEXT SEARCH DICTIONARY
unaccent (RULES=‘unaccent’);”)
ActiveRecord::Base.connection.execute(“CREATE TEXT SEARCH CONFIGURATION
es ( COPY = spanish );”)
ActiveRecord::Base.connection.execute(“ALTER TEXT SEARCH CONFIGURATION
ALTER MAPPING FOR hword, hword_part, word
WITH unaccent, spanish_stem;”)

This works perfectly in develpment.

Now I want to run some search tests, but when I execute my functional
tests, I get an error saying that the extension is not configured:

ActiveRecord::StatementInvalid: PG::Error: ERROR: function
unaccent(text) does not exist

So I assume I have to do the same that I did for development, but for
test environment.

How can I do it in a clean way?

RAILS_ENV=test rake db:migrate

Or you might have to specify:
RAILS_ENV=test rake db:migrate:up VERSION={put your migration number

It’s likely that the normal db:test:prepare task doesn’t support these