mongodb/jstests/core/db.js

function testInvalidDBNameThrowsExceptionWithConstructor() {
    assert.throws(function() {
        return new DB(null, "/\\");
    });
}

function testInvalidDBNameThrowsExceptionWithSibling() {
    assert.throws(function() {
        return db.getSiblingDB("/\\");
    });
}

testInvalidDBNameThrowsExceptionWithConstructor();
testInvalidDBNameThrowsExceptionWithSibling();