fix type

CovOpen · Apr 19, 2021 · 5a67774 · 5a67774
1 parent c05bdeb
commit 5a67774
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/covquestions-js/src/questionnaireEngine.ts b/covquestions-js/src/questionnaireEngine.ts
@@ -363,7 +363,7 @@ export class QuestionnaireEngine {
     function convertToDateString(
       timestamp?: LogicExpression,
       dateFormat?: LogicExpression
-    ): string {
+    ): string | null {
       if (!timestamp || !dateFormat) {
         return null;
       }