Model/backend/documents_parser
Khalim Conn-Kowlessar 1f8a070f66 Slice S0380.19: count Elmhurst shower outlets by type (no more hardcoded 1)
Surfaces the lodged shower multiplicity from the Elmhurst Summary §16
on the EPC. Previously `_map_elmhurst_sap_heating` hardcoded:

  electric_shower_count = 1 if has_electric_shower else None
  mixer_shower_count    = 0 if has_electric_shower else None

losing the count for any cert with ≥ 2 outlets. Cert
7800-1501-0922-7127-3563 lodges TWO instantaneous electric showers
("Shower 01" + "Shower 11") but the mapper produced
`electric_shower_count=1`. After this slice:

  electric_shower_count = Σ(s for s in showers if s.outlet_type
                              == "Electric shower")
  mixer_shower_count    = Σ(s for s in showers if s.outlet_type
                              != "Electric shower")

**Cascade SAP effect:** None on cert 7800. Appendix J's eq J16
(`N_ES,per_outlet = N_shower / N_outlets`) and eq J18 (Σ_j E_ES,j)
are symmetric in N_electric_showers when there are no mixer outlets,
so the lodged (64a) kWh and (247a) cost are unchanged. The fix is
correctness-by-construction, not a delta-closer for the negative-band
certs (their +0.69 GBP total-cost gap traces to the gas hot-water
kWh path — separate slice).

**Hand-built fixture updates (5):** the cohort-1 hand-builts at
`domain/sap10_calculator/worksheet/tests/_elmhurst_worksheet_*.py`
previously omitted `electric_shower_count` / `mixer_shower_count`
(implicitly None), which matched the mapper's pre-slice None
sentinel. Updated each to the lodged counts the mapper now surfaces:
  000474: 1 mixer  → (0, 1)
  000477: 1 mixer  → (0, 1)
  000480: 1 mixer  → (0, 1)
  000490: 1 mixer  → (0, 1)
  000516: 1 mixer  → (0, 1)
000487 (already at (1, 0) for an electric-shower lodging) unchanged.

Tests:
- `test_summary_7800_two_electric_showers_count_as_two_not_one` —
  pins the multi-shower mapping for cert 7800 (Summary_000890.pdf).
- 5 hand-built field-parity tests
  (`test_from_elmhurst_site_notes_matches_hand_built_*`) now pass at
  the new integer counts instead of None.

Pyright net-zero per file:
- datatypes/epc/domain/mapper.py: 32 (baseline 32)
- backend/documents_parser/tests/test_summary_pdf_mapper_chain.py: 0

Regression baseline: 699 pass + 10 fail (= prior 698 + 10 + 1 new).

Spec refs:
- SAP 10.2 Appendix J §1a — outlet counting drives `N_outlets` used
  in eq J6/J7 (mixer shower water draw) and eq J16/J17/J18 (electric
  shower energy).
- Cert 7800-1501-0922-7127-3563 Summary §16 "Showers" lodgement.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-28 07:16:32 +00:00
..
handler address JTK review comments 2026-04-20 15:11:17 +00:00
tests Slice S0380.19: count Elmhurst shower outlets by type (no more hardcoded 1) 2026-05-28 07:16:32 +00:00
__init__.py Map to RdSapSiteNotes from site notes JSON 🟥 2026-04-16 13:54:03 +00:00
db_writer.py include updating epc_property_data to pashub to ara workflow 2026-04-29 09:55:14 +00:00
elmhurst_extractor.py Slice S0380.12: parse 'Alternative wall' window-location in pre-data slice 2026-05-27 21:27:47 +00:00
extractor.py Handle wall thickness "Unmeasurable" 🟩 2026-04-30 16:41:16 +00:00
local_runner.py update local runner to work for elmhurst 2026-04-24 14:01:36 +00:00
parser.py load ecmk site notes to db 2026-04-29 11:20:47 +00:00
pdf.py update local runner to work for elmhurst 2026-04-24 14:01:36 +00:00