MAINT: Use `new Error`

src/Entity.js

@@ -39,7 +39,7 @@ function _getRoleString(role) {
     case roles.ENTITY_ROLE_FILE:
         return "FILE";
     default:
-        throw `Unknown role ${role}.`;
+        throw new Error(`Unknown role ${role}.`);
     }
 }
 

src/Property.js

@@ -37,7 +37,7 @@ function _getScalarValue(value) {
     case valueCases.SPECIAL_VALUE:
         return value.getSpecialValue();
     default:
-        throw `Unkown value type ${value.getScalarValueCase()}.`;
+        throw new Error(`Unkown value type ${value.getScalarValueCase()}.`);
     }
 }
 
@@ -78,7 +78,7 @@ export class Property {
         case valueCases.LIST_VALUES:
             return _getListValue(wrappedValue.getListValues().getValuesList());
         default:
-            throw `Unknown value type ${wrappedValue.getValueCase()}.`;
+            throw new Error(`Unknown value type ${wrappedValue.getValueCase()}.`);
         }
     }