Merge pull request #4387 from sul-dlss/4386-blank-ids

Guard against blank ids for availability lookups. Fixes #4386

app/controllers/availability_controller.rb

@@ -15,6 +15,6 @@ def redirect_bots
   end
 
   def redirect_no_ids
-    render json: [] unless params[:ids].present?
+    render json: [] unless Array(params[:ids]).compact_blank.present?
   end
 end

app/services/live_lookup.rb

@@ -6,7 +6,7 @@ class LiveLookup
   delegate :as_json, :to_json, to: :records
 
   def initialize(ids)
-    @ids = [ids].flatten.compact
+    @ids = Array(ids).compact_blank
   end
 
   # Uses the LiveLookup service specified by Settings.live_lookup_service

spec/controllers/availability_controller_spec.rb

@@ -19,6 +19,14 @@
     end
   end
 
+  describe "with a blank ID" do
+    it "should render a blank JSON array w/o making a live lookup request" do
+      expect(LiveLookup).not_to receive(:new)
+      get :index, params: { ids: [''] }
+      expect(response.body).to eq '[]'
+    end
+  end
+
   describe "with IDs" do
     let(:lookup) { double('new') }
     let(:json) { [{ a: 'a', b: 'b' }] }