Adding test to ensure empty collections behave correctly.

Author: tjdett

lib/oai/provider/model/activerecord_wrapper.rb

@@ -26,13 +26,13 @@ def initialize(model, options={})
     end
 
     def earliest
-      model.find(:first,
-        :order => "#{timestamp_field} asc").send(timestamp_field)
+      earliest_obj = model.find(:first, :order => "#{timestamp_field} asc")
+      earliest_obj.nil? ? Time.at(0) : earliest_obj.send(timestamp_field)
     end
 
     def latest
-      model.find(:first,
-        :order => "#{timestamp_field} desc").send(timestamp_field)
+      latest_obj = model.find(:first, :order => "#{timestamp_field} desc")
+      latest_obj.nil? ? Time.now : latest_obj.send(timestamp_field)
     end
     # A model class is expected to provide a method Model.sets that
     # returns all the sets the model supports.  See the

test/activerecord_provider/tc_ar_provider.rb

@@ -94,6 +94,21 @@ def test_from_and_until
     assert_equal 40, doc.elements['OAI-PMH/ListRecords'].to_a.size
   end
 
+  def test_handles_empty_collections
+    DCField.delete_all
+    assert DCField.count == 0
+    # Identify and ListMetadataFormats should return normally
+    test_identify
+    test_metadata_formats
+    # ListIdentifiers and ListRecords should return "noRecordsMatch" error code
+    assert_raises(OAI::NoMatchException) {
+      REXML::Document.new(@provider.list_identifiers)
+    }
+    assert_raises(OAI::NoMatchException) {
+      REXML::Document.new(@provider.list_records)
+    }
+  end
+
   def setup
     @provider = ARProvider.new
   end