spec: don't truncate cassandra in tests

Turns out that truncate is a super slow operation in Cassandra. For the
tests that this affects, we'll handle the potentially non-empty db.

Change-Id: Ie7e64add3b53f26eb98ba441e46270a8c08657ea
Reviewed-on: https://gerrit.instructure.com/36593
Reviewed-by: Jacob Fugal <jacob@instructure.com>
Product-Review: Shawn Meredith <shawn@instructure.com>
QA-Review: Shawn Meredith <shawn@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>

lib/data_fixup/filter_page_view_url_params.rb

@@ -28,6 +28,7 @@ module DataFixup::FilterPageViewUrlParams
       rows = get_rows(last_request_id, batch_size)
       break if rows.empty?
       rows.each do |pv|
+        next if !pv.url
         pv.url = LoggingFilter.filter_uri(pv.url)
         PageView::EventStream.update(pv) if pv.url_changed?
       end

spec/spec_helper.rb

@@ -277,15 +277,6 @@ def truncate_all_tables
   end
 end
 
-def truncate_all_cassandra_tables
-  Canvas::Cassandra::DatabaseBuilder.config_names.each do |cass_config|
-    db = Canvas::Cassandra::DatabaseBuilder.from_config(cass_config)
-    db.tables.each do |table|
-      db.execute("TRUNCATE #{table}")
-    end
-  end
-end
-
 # wipe out the test db, in case some non-transactional tests crapped out before
 # cleaning up after themselves
 truncate_all_tables
@@ -440,7 +431,6 @@ end
     Attachment.clear_cached_mime_ids
     RoleOverride.clear_cached_contexts
     Delayed::Job.redis.flushdb if Delayed::Job == Delayed::Backend::Redis::Job
-    #truncate_all_cassandra_tables
     Rails::logger.try(:info, "Running #{self.class.description} #{@method_name}")
     Attachment.domain_namespace = nil
   end