fix(client): dateOfFirstActivity type safety

apps/client/src/app/components/holding-detail-dialog/holding-detail-dialog.component.ts

@@ -297,7 +297,11 @@ export class GfHoldingDetailDialogComponent implements OnInit {
           this.benchmarkDataItems = [];
           this.countries = {};
           this.dataProviderInfo = dataProviderInfo;
-          this.dateOfFirstActivity = dateOfFirstActivity;
+
+          if (dateOfFirstActivity) {
+            this.dateOfFirstActivity = dateOfFirstActivity;
+          }
+
           this.dividendInBaseCurrency = dividendInBaseCurrency;
 
           if (

libs/ui/src/lib/services/data.service.ts

@@ -447,7 +447,7 @@ export class DataService {
     symbol: string;
   }): Observable<
     Omit<PortfolioHoldingResponse, 'dateOfFirstActivity'> & {
-      dateOfFirstActivity: Date;
+      dateOfFirstActivity: Date | undefined;
     }
   > {
     return this.http
@@ -456,9 +456,13 @@ export class DataService {
       )
       .pipe(
         map((response) => {
+          const dateOfFirstActivity = response.dateOfFirstActivity
+            ? parseISO(response.dateOfFirstActivity)
+            : undefined;
+
           return {
             ...response,
-            dateOfFirstActivity: parseISO(response.dateOfFirstActivity)
+            dateOfFirstActivity
           };
         })
       );