Required files
shoulda/active_record/helpers
shoulda/active_record/matchers/validation_matcher
shoulda/active_record/matchers/allow_value_matcher
shoulda/active_record/matchers/ensure_length_of_matcher
shoulda/active_record/matchers/ensure_inclusion_of_matcher
shoulda/active_record/matchers/validate_presence_of_matcher
shoulda/active_record/matchers/validate_format_of_matcher
shoulda/active_record/matchers/validate_uniqueness_of_matcher
shoulda/active_record/matchers/validate_acceptance_of_matcher
shoulda/active_record/matchers/validate_numericality_of_matcher
shoulda/active_record/matchers/association_matcher
shoulda/active_record/matchers/have_db_column_matcher
shoulda/active_record/matchers/have_db_index_matcher
shoulda/active_record/matchers/have_readonly_attribute_matcher
shoulda/active_record/matchers/allow_mass_assignment_of_matcher