Move missing statements to where + delete_all

And fix the specs

lib/tasks/data/remove_transient_data.rb

@@ -11,8 +11,8 @@ class RemoveTransientData
     Rails.logger.info("#{self.class.name}: processing")
 
     Spree::StateChange.where("created_at < ?", retention_period).delete_all
-    Spree::LogEntry.delete_all("created_at < '#{retention_period}'")
-    Session.delete_all("updated_at < '#{retention_period}'")
+    Spree::LogEntry.where("created_at < ?", retention_period).delete_all
+    Session.where("updated_at < ?", retention_period).delete_all
   end
 
   private

spec/lib/tasks/data/remove_transient_data_spec.rb

@@ -14,28 +14,27 @@ describe RemoveTransientData do
       allow(Rails.logger).to receive(:info)
     end
 
-    it 'deletes state changes older than a month' do
-      RemoveTransientData.new.call
+    it 'deletes state changes older than rentention_period' do
+      Spree::StateChange.create(created_at: retention_period - 1.day)
 
-      expect(Spree::StateChange)
-        .to have_received(:delete_all)
-        .with("created_at < '#{retention_period}'")
+      RemoveTransientData.new.call
+      expect(Spree::StateChange.all).to be_empty
     end
 
     it 'deletes log entries older than a month' do
+      Spree::LogEntry.create(created_at: retention_period - 1.day)
+
       RemoveTransientData.new.call
 
-      expect(Spree::LogEntry)
-        .to have_received(:delete_all)
-        .with("created_at < '#{retention_period}'")
+      expect(Spree::LogEntry.all).to be_empty
     end
 
-    it 'deletes sessions older than two weeks' do
+    it 'deletes sessions older than retention_period' do
+      RemoveTransientData::Session.create(session_id: 1, updated_at: retention_period - 1.day)
+
       RemoveTransientData.new.call
 
-      expect(RemoveTransientData::Session)
-        .to have_received(:delete_all)
-        .with("updated_at < '#{retention_period}'")
+      expect(RemoveTransientData::Session.all).to be_empty
     end
   end
 end