thoughtbot/shoulda-matchers — pull request #440 by petedmarsh (2014-02-11 00:06:49+00:00)
Title: Change `validate_uniqueness_of_matcher` to give non-null columns default values

Previously, if a model had an attribute that mapped to a non-nullable database
column that was not under test the matcher would fail with an SQL error like:

examples.column may not be NULL #...

With this change the matcher attempts to provide a default value for all
non-nullable, non-primary attributes. This should avoid the above error in
simple cases.