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 “or” 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