Update ferial-Preces TODO note to mention the Vigil-day change

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HWN869GrMFHqrer9fdCBbF

TODO.md

@@ -21,13 +21,15 @@ across every hour and content type in this app.
    it from starting:
    - Easter's own octave — tabled, "a whole different discussion."
    - Prime's ferial Preces (`data/propers/common/prime-preces-feriales.yml`, the older
-     pre-1911-reform "Eripe me, Domine" text) currently show on *every* ferial day
-     (`hours/prime.yml`'s `by-day-kind` split) — by explicit choice, more generous than the
-     historical rubric, which restricted this text to Advent/Lent/vigils/Ember days only.
-     Narrowing the gating to match, if ever wanted, is open, not started. Prime's Sunday/feast
-     Preces (`prime-preces-dominicales.yml`) were separately switched from Monastic's own form
-     to the secular Tridentine form (2026-08-25, keeping Benedict in the Confiteor by explicit
-     choice) — see that file's header.
+     pre-1911-reform "Eripe me, Domine" text) currently show on *every* plain ferial day and
+     every Vigil day (`hours/prime.yml`'s `by-day-kind` split, `vigilIsFerial: true`) — by
+     explicit choice, more generous than the historical rubric, which restricted this text to
+     Advent/Lent/vigils/Ember days only. Narrowing the gating further (e.g. to Advent/Lent/Ember
+     too) to match, if ever wanted, is open, not started. Prime's Sunday/feast Preces
+     (`prime-preces-dominicales.yml`) were separately switched from Monastic's own form to the
+     secular Tridentine form (2026-08-25, keeping Benedict in the Confiteor by explicit choice)
+     — see that file's header. The capitulum's own by-day-kind split is unaffected by
+     `vigilIsFerial` — a Vigil day still gets the Sunday/feast capitulum, only the Preces moved.
    - What "a Gospel reading is its own kind" should mean structurally/in the UI, beyond the
      `isGospel` flag on a plain Matins `lesson` — open; deferred until there's a UI to
      evaluate it against.

src/data/hours/prime.yml

@@ -30,6 +30,12 @@
 # ferial Preces are said on *every* ferial day, not just Advent/Lent/
 # vigils/Ember days the way later rubrics restricted them.
 #
+# Preces additionally set `vigilIsFerial: true` — isSundayOrFeastOffice on
+# its own treats any sanctoral winner, Vigils included, as a "feast," but
+# by explicit choice a Vigil day gets the ferial Preces instead. The
+# capitulum doesn't set this flag, so a Vigil still gets the Sunday/feast
+# capitulum, same as before.
+#
 # Preces deliberately use the *secular* Tridentine form
 # (propers/common/prime-preces-dominicales.yml), not Monastic Prime's own
 # shorter Dominicales form — chosen because the secular form keeps content
@@ -65,6 +71,7 @@ parts:
   - kind: by-day-kind
     resolvedKind: preces
     omitOnDouble: true
+    vigilIsFerial: true
     sundayOrFeastRef: { source: common, id: prime-preces-dominicales }
     ferialRef: { source: common, id: prime-preces-feriales }
   - kind: prayer

src/hours/prime.ts

@@ -97,10 +97,13 @@ function resolvePart(part: HourPart, date: string, day: LiturgicalDay): Resolved
     case 'canticle':
       return [{ kind: 'canticle', canticleId: part.canticleId, text: resolveCommon(part.textRef.id) }];
     case 'by-day-kind': {
-      if (part.omitOnDouble && isDoubleOrHigher(resolveOfficeWinner(day))) {
+      const winner = resolveOfficeWinner(day);
+      if (part.omitOnDouble && isDoubleOrHigher(winner)) {
         return [];
       }
-      const ref = isSundayOrFeastOffice(day) ? part.sundayOrFeastRef : part.ferialRef;
+      const isVigil = winner.kind === 'sanctoral' && winner.rank === 'vigil';
+      const useFeastForm = isSundayOrFeastOffice(day) && !(part.vigilIsFerial && isVigil);
+      const ref = useFeastForm ? part.sundayOrFeastRef : part.ferialRef;
       if (part.resolvedKind === 'preces') {
         return [{ kind: 'preces', text: resolveCommon(ref.id), label: part.label }];
       }

src/hours/types.ts

@@ -61,6 +61,12 @@ export type HourPart =
       resolvedKind: 'chapter' | 'preces';
       label?: string;
       omitOnDouble?: true;
+      // When true, a Vigil-ranked sanctoral winner takes the ferialRef
+      // instead of the sundayOrFeastRef isSundayOrFeastOffice would
+      // otherwise give it (that function treats any sanctoral winner,
+      // Vigils included, as a "feast"). Prime's Preces use this; its
+      // capitulum doesn't.
+      vigilIsFerial?: true;
       sundayOrFeastRef: PropersRef;
       ferialRef: PropersRef;
     }

tests/hours/prime.test.ts

@@ -130,6 +130,25 @@ describe('resolveOrdo("prime", ...)', () => {
     ).toContain('Et ego ad te, Dómine, clamávi');
   });
 
+  it('uses the ferial Preces (but the Sunday/feast capitulum) on a Vigil day', () => {
+    // 2025-11-29: a real, unimpeded Vigil of St. Andrew — day.winner is
+    // itself sanctoral/vigil (not merely commemorated), see
+    // data/calendar/saints/vigil-of-st-andrew.yml's own header comment.
+    const VIGIL = '2025-11-29';
+    const ordo = resolveOrdo('prime', VIGIL);
+    const chapter = ordo.parts.find((p) => p.kind === 'chapter');
+    // The capitulum doesn't set vigilIsFerial, so it stays on the
+    // Sunday/feast form even on a Vigil day.
+    expect(chapter && chapter.kind === 'chapter' ? chapter.text.text.en : undefined).toBe(
+      'Now to the king of ages, immortal, invisible, the only God, be honour and glory for ever and ever. Amen.',
+    );
+    const preces = ordo.parts.filter((p) => p.kind === 'preces');
+    const ferialPreces = preces.find((p) => p.kind === 'preces' && p.text.text.la?.startsWith('V. Éripe me'));
+    expect(ferialPreces).toBeDefined();
+    const dominicalPreces = preces.find((p) => p.kind === 'preces' && p.text.text.la?.includes('Confíteor Deo'));
+    expect(dominicalPreces).toBeUndefined();
+  });
+
   it('gives the capitulum its scripture citation', () => {
     const ordo = resolveOrdo('prime', MONDAY);
     const chapter = ordo.parts.find((p) => p.kind === 'chapter');