Merge pull request #900 from sul-dlss/pref-cn-fix

Handle preferred barcodes that don't exist in the holdings.

lib/holdings.rb

@@ -19,10 +19,13 @@ def find_by_barcode(barcode)
     end
   end
   def preferred_callnumber
-    @preferred_callnumber ||= if @document[:preferred_barcode]
-      find_by_barcode(@document[:preferred_barcode])
-    else
-      callnumbers.first
+    @preferred_callnumber ||= begin
+      if @document[:preferred_barcode] &&
+         (found_callnumber = find_by_barcode(@document[:preferred_barcode])).present?
+        found_callnumber
+      else
+        callnumbers.first
+      end
     end
   end
   def present?

spec/lib/holdings_spec.rb

@@ -106,6 +106,17 @@
         )
       )
     }
+    let(:bad_preferred) {
+      Holdings.new(
+        SolrDocument.new(
+          preferred_barcode: 'does-not-exist',
+          item_display: [
+            '54321 -|- GREEN -|- STACKS -|-  -|- -|- -|- -|- -|- callnumber1 -|- 1',
+            '12345 -|- GREEN -|- STACKS -|-  -|- -|- -|- -|- -|- callnumber2 -|- 2'
+          ]
+        )
+      )
+    }
     let(:no_preferred) {
       Holdings.new(
         SolrDocument.new(
@@ -119,6 +130,9 @@
     it 'should return the callnumber based on preferred barcode' do
       expect(preferred.preferred_callnumber.barcode).to eq '12345'
     end
+    it 'should return the first callnumber when the preferred barcode does not exist in the holdings' do
+      expect(bad_preferred.preferred_callnumber.barcode).to eq '54321'
+    end
     it 'should return the first callnumber if there is no preferred barcode available' do
       expect(no_preferred.preferred_callnumber.barcode).to eq '54321'
     end