The
database_cleaner
gem is a handy way to make sure you have a consistent database context for
each test example or suite. One database_cleaner strategy that can be used
is the truncation strategy. This truncates the data from all the tables by
default. This is not ideal for fixed tables that contain domain-specific
data because you end up having to do way more test setup than should be
necessary. Fortunately, specific tables can be excepted by the truncation
strategy using the except option.
For instance, if we have a standard set of roles for users of our
application, we can except that table from truncation with a line like the
following in our rails_helper.rb file:
DatabaseCleaner.strategy = :truncation, {:except => %w[roles]}