fix(mtconnect): resetTriggered only resets data sets; empty set is Good {}; re-baseline test (#650 review)

Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
2026-10-08 19:20:23 -04:00
parent f8f8eb9fb8
commit 9631a40f1f
6 changed files with 123 additions and 13 deletions
@@ -291,6 +291,7 @@ type inference already type these items String):
  `resetTriggered` observation with no entries is the empty set `{}`. Several observations of one item in one
  document fold in document order. The accumulated set is dropped on an Agent restart (`instanceId` change).
 - `removed="true"` deletes the key (or row): it is **absent** from the JSON, never `null`.
+- **Empty set is Good `{}`**: a data-set-shaped observation (it carries the `count` attribute, which only DATA_SET/TABLE have) with no entries - `count="0"` in a `/current`, or `resetTriggered` - is the empty set, `{}`, never an absence; an all-removed set renders the same. `resetTriggered` on any other observation (e.g. an accumulating `PartCount`) is ignored.
 - `UNAVAILABLE` is `BadNoCommunication` as for any observation, and also drops the accumulated set, so a
  later delta cannot resurrect pre-outage entries.
 - An observation whose children are not `<Entry>` elements stays `BadNotSupported`. Writes to these items stay