[MICROBA-746] Improve this code to check for the availability of banner_images

lms/static/js/learner_dashboard/models/program_model.js

@@ -12,9 +12,9 @@ class ProgramModel extends Backbone.Model {
         subtitle: data.subtitle,
         authoring_organizations: data.authoring_organizations,
         detailUrl: data.detail_url,
-        xsmallBannerUrl: data.banner_image['x-small'].url,
-        smallBannerUrl: data.banner_image.small.url,
-        mediumBannerUrl: data.banner_image.medium.url,
+        xsmallBannerUrl: (data.banner_image && data.banner_image['x-small']) ? data.banner_image['x-small'].url : '',
+        smallBannerUrl: (data.banner_image && data.banner_image.small) ? data.banner_image.small.url : '',
+        mediumBannerUrl: (data.banner_image && data.banner_image.medium) ? data.banner_image.medium.url : '',
         breakpoints: {
           max: {
             xsmall: '320px',

lms/static/js/learner_dashboard/spec/program_card_view_spec.js

@@ -88,6 +88,7 @@ describe('Program card View', () => {
 
   it('should load the program-card based on passed in context', () => {
     cardRenders(view.$el);
+    expect(view.$el.find('.banner-image').attr('srcset')).toEqual(program.banner_image.small.url);
   });
 
   it('should call reEvaluatePicture if reLoadBannerImage is called', () => {
@@ -127,4 +128,32 @@ describe('Program card View', () => {
     cardRenders(view.$el);
     expect(view.$('.progress').length).toEqual(0);
   });
+
+  it('should render cards if there are missing banner images', () => {
+    view.remove();
+    const programNoBanner = JSON.parse(JSON.stringify(program));
+    delete programNoBanner.banner_image;
+    programModel = new ProgramModel(programNoBanner);
+    view = new ProgramCardView({
+      model: programModel,
+      context: {},
+    });
+    cardRenders(view.$el);
+    expect(view.$el.find('.banner-image').attr('srcset')).toEqual('');
+  });
+
+  it('should render cards if there are missing banner image sizes', () => {
+    view.remove();
+    const programNoBanner = JSON.parse(JSON.stringify(program));
+    delete programNoBanner.banner_image['x-small'];
+    delete programNoBanner.banner_image.small;
+
+    programModel = new ProgramModel(programNoBanner);
+    view = new ProgramCardView({
+      model: programModel,
+      context: {},
+    });
+    cardRenders(view.$el);
+    expect(view.$el.find('.banner-image').attr('srcset')).toEqual('');
+  });
 });