id: no-demeter-message-chain
valid:
  # promise chain — `then` is not an accessor
  - "fetch(url).then(r => r.json()).then(d => use(d));"
  # fluent collection ops — map/filter/value are not accessors
  - "const r = _(arr).map(f).filter(g).value();"
  # query/DSL builder — select/from/where are not accessors
  - 'const q = db.select("*").from("t").where("x");'
  # only 2 deep
  - "const v = obj.getA().doB();"
  # single accessor
  - "const got = single.getThing();"
invalid:
  - "const city = order.getCustomer().getAddress().getCity();"
  - "const v = a.getB().getC().doD();"
  - "const ok = session.getUser().isActive().valueOf();"