Validation of what the field can receive

I did the validation that the field can receive from 0 to 10, until then it is working, however when placing || (or) null, the test fails when given the value of null, says it expects it to be a number or date.
Where am I wrong? Please help me!

Below the code:

pm.expect(req.field).to.above(-1).to.below(11)||typeof (req.field==null);
});

test response
image

I am validating the raw of the request, the field is receiving null but it still gives this error. Is the β€œor” not working?

you cannot use or in pm.expect as it will through a exception not boolean

use :

pm.test("Some name", function () {

    preq.field? pm.expect(req.field).to.above(-1).to.below(11): pm.expect(req.field).to.be.null

});

this will validate first option if not null else second expect