bugfixes as identified by new test case #3

Author: stschr

src/dash/models/DashManifestModel.js

@@ -1053,7 +1053,7 @@ function DashManifestModel() {
         }
 
         const mainAS = getMainAdaptationSetForPreselection(preselection, adaptations);
-        return mainAS.Representation[0];
+        return (mainAS ? mainAS.Representation[0] : undefined);
     }
 
     function getPreselectionsForPeriod(voPeriod) {

test/unit/mocks/AdapterMock.js

@@ -246,8 +246,9 @@ function AdapterMock() {
     }
 
     this.getCommonRepresentationForPreselection = function (preselection, adaptations) {
-        const id = preselection.preselectionComponents.split(' ')[0]
-        return adaptations.find((as) => as.id == id).Representation[0]
+        const id = preselection.preselectionComponents.split(' ')[0];
+        const as = adaptations.find((as) => as.id == id);
+        return (as ? as.Representation[0] : undefined);
     }
 
 }

test/unit/mocks/CapabilitiesMock.js

@@ -45,6 +45,10 @@ class CapabilitiesMock {
     isCodecSupportedBasedOnTestedConfigurations() {
         return true;
     }
+
+    supportsEssentialProperty() {
+        return true;
+    }
 }
 
 export default CapabilitiesMock;