Try equating to undefined

Author: mayank1513

cypress/e2e/test_form.cy.js

@@ -60,6 +60,7 @@ context('Form', () => {
         const data = JSON.parse(content);
 
         // expect(data.due_date).to.equal('Invalid date'); <- Mui doesn't allow setting invalid date
+        expect(data.due_date).to.equal(undefined);
       });
   });
 });