Bug fix - missing trigger keywords (null) crashed the progress bar

app/src/pages/write-tweet/write-tweet.ts

@@ -66,15 +66,19 @@ export class WriteTweetPage {
 
   private containsTriggerWord(triggerWords: string): ValidatorFn {
     return (control: AbstractControl): { [key: string]: any } | null => {
-      const regexList = triggerWords
-        .toLowerCase()
-        .split(", ")
-        .join("|");
-      const regex = new RegExp(regexList);
-      const containsTriggerWord = regex.test(control.value.toLowerCase());
-      return containsTriggerWord
-        ? { containsTriggerWord: { value: control.value } }
-        : null;
+      if (triggerWords) {
+        const regexList = triggerWords
+          .toLowerCase()
+          .split(", ")
+          .join("|");
+        const regex = new RegExp(regexList);
+        const containsTriggerWord = regex.test(control.value.toLowerCase());
+        return containsTriggerWord
+          ? { containsTriggerWord: { value: control.value } }
+          : null;
+      } else {
+        return null;
+      }
     };
   }