t = db.eval3;
t.drop();

t.save({_id: 1, name: "eliot"});
assert.eq(1, t.count(), "A");

function z(a, b) {
    db.eval3.save({_id: a, name: b});
    return b;
}

z(2, "sara");
assert.eq(2, t.count(), "B");

assert.eq("eliot,sara",
          t.find()
              .toArray()
              .map(function(z) {
                  return z.name;
              })
              .sort()
              .toString());

assert.eq("joe", db.eval(z, 3, "joe"), "C");
assert.eq(3, t.count(), "D");

assert.eq("eliot,joe,sara",
          t.find()
              .toArray()
              .map(function(z) {
                  return z.name;
              })
              .sort()
              .toString());