Empty question fix

src/utils/classes.ts

@@ -126,7 +126,9 @@ function compareString(string1: string, string2: string) {
 }
 
 function answerPreProcessor(value: string) {
-  assert(value)
+  if (!value) {
+    return value
+  }
 
   return removeStuff(value, commonUselessAnswerParts)
 }
@@ -208,7 +210,7 @@ function createQuestion(
 ): Question {
   return {
     Q: simplifyQuestion(question),
-    A: answer ? simplifyAnswer(answer) : null,
+    A: answer ? simplifyAnswer(answer) : undefined,
     data: data,
   }
 }