fix(audit): alias learning is not a rule change, stop logging it (BFNAR noise) (#2134)

Production falsified 20260901103000's exclusion list within 30 minutes of deploy: 15 of the first 16 UPDATE audit rows on categorization_templates changed only the learning columns plus counterparty_aliases, because the learning path (lib/bookkeeping/counterparty-templates.ts) merges new aliases in the same write that bumps occurrence_count. Projected ~800 noise rows/day against ~50/day of real rule changes, each one rendered into the legally-facing behandlingshistorik as "Konteringsmall aendrad: Alias". counterparty_aliases joins the trigger's strip list. The trade-off is explicit: a human editing ONLY aliases is no longer logged. Accepted because alias growth is overwhelmingly automatic, and a change that also touches accounts, VAT, pattern or the active flag still logs: the first real such row (2026-09-01 19:02:17Z, debit/credit/vat accounts changed by the learning loop, BFN's automatkontering case exactly) was captured correctly and stays captured under the new WHEN clause. The pre-fix noise rows stay in audit_log (append-only). The read model stops labelling the column, so alias-only diffs, historical ones included, render as no-ops rather than rule changes; a diff that also carries a real change shows only the real change. pg-test extended: alias+learning update writes no audit row, alias+account update still does. Read-model test pins the pre-fix noise row shape to null. Claude-Session: https://claude.ai/code/session_01L3P2hr19PhQuCoTSGoegcY Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com> Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
2026-09-01 21:58:02 +02:00
parent 53c9c0c4f9
commit 191fb2cfce
5 changed files with 81 additions and 12 deletions
@@ -0,0 +1,47 @@
+-- Stop alias learning from flooding the behandlingshistorik audit trail.
+--
+-- 20260901103000 added the audit trigger on categorization_templates with a
+-- WHEN clause excluding the learning columns (occurrence_count, confidence,
+-- last_seen_date, updated_at). Production falsified the list within 30
+-- minutes of deploy: 15 of the first 16 UPDATE audit rows changed only those
+-- columns plus counterparty_aliases, because the learning path
+-- (lib/bookkeeping/counterparty-templates.ts) merges new aliases in the same
+-- write that bumps occurrence_count. Projected ~800 noise rows/day against
+-- ~50/day of real rule changes, every one of them rendered into the
+-- legally-facing report as "Konteringsmall aendrad: Alias ...".
+--
+-- counterparty_aliases joins the strip list. The trade-off is explicit: a
+-- human editing ONLY the aliases of a template is no longer logged either.
+-- Accepted because alias growth is overwhelmingly automatic, and a change
+-- that also touches accounts, VAT, pattern or active flag still logs (the
+-- first real such row, 2026-09-01 19:02:17Z, changed debit/credit/vat
+-- accounts alongside learning columns and was correctly captured).
+--
+-- The noise rows already written stay: audit_log is append-only. The read
+-- model stops labelling the column, so they render as no-ops.
+--
+-- pg-test: tests/pg/behandlingshistorik-audit-triggers.pg.test.ts
+
+DROP TRIGGER audit_categorization_templates_update ON public.categorization_templates;
+
+CREATE TRIGGER audit_categorization_templates_update
+  AFTER UPDATE ON public.categorization_templates
+  FOR EACH ROW
+  WHEN (
+    (to_jsonb(OLD) - ARRAY[
+      'occurrence_count',
+      'confidence',
+      'last_seen_date',
+      'updated_at',
+      'counterparty_aliases'
+    ]::text[])
+    IS DISTINCT FROM
+    (to_jsonb(NEW) - ARRAY[
+      'occurrence_count',
+      'confidence',
+      'last_seen_date',
+      'updated_at',
+      'counterparty_aliases'
+    ]::text[])
+  )
+  EXECUTE FUNCTION public.write_audit_log();