Why doesn't the input event object in Jest match the object in the browser?

Question

Software testing

Product testing on vue happens through jest and vue test utils. I set the value in the field via setValue:

it('should input only numbers', () => {
  const wrapper = shallowMount(CodeInput);
  wrapper.find('.code-input__cell').setValue('a');

  expect(wrapper.vm.value).toBeFalsy();
});

In the component code, I check through the data property that it is not a number entered:

onInput(e) {
  if (!Number.isInteger(Number(e.data))) return false;
// ...
}

I noticed that when running the tests, the execution ends at this check and realized that the data property does not exist in the test runtime:

onInput(e) {
    if (e.data) {
      console.log('data существует');
    } else {
      console.log('data не существует', { ...e })
    } 
// ...

}

Why is this done and how can I solve my problem?