fix(of): correct the Annunciation's transfer_target slug, dead Rule 1

precedence_of.ml's transfer_target Rule 1 (Normae n. 60's fixed Easter+8
destination for the Annunciation falling in Holy Week) keyed off
"of-annunciation", a placeholder that never matched the real shipped
entry's own slug ("annunciation-of-the-lord",
data/of/calendar-2002.sexp). Rule 1 was therefore dead code: it could
only ever fire against test_precedence_of.ml's own synthetic candidate,
which happened to carry the identical placeholder.

Output was nonetheless correct on shipped data (latent, not live): Rule
3's general forward search structurally converges on the same Easter+8
target, because the Easter Octave occupies exactly Easter+1..+7 at band
20 and the 3-9 April window carries only memorials on the universal
calendar. The exposure is an overlay placing a proper solemnity (band
40) or proper feast (band 80) anywhere in 3-9 April, where Rule 3 would
diverge from Rule 1's fixed destination and Rule 1 would silently fail
to override it.

Fixed the slug, and updated the existing Rule-1 tests' own synthetic
candidate to the real slug so they keep exercising Rule 1 rather than
Rule 3's coincidental agreement. Added a test that tells the two rules
apart rather than only checking the output they happen to agree on: it
rigs the occupant callback to occupy Easter+8 with a synthetic
Tabula-entry-3 candidate, confirms (via a control case using a
different solemnity) that the rig genuinely forces Rule 3's search past
that date, then shows the real shipped Annunciation still lands on
Easter+8 despite the block -- only explicable by Rule 1 firing, not by
Rule 3 happening to agree.

1 files changed, 70 insertions, 1 deletions

diff --git a/test/test_precedence_of.ml b/test/test_precedence_of.ml
index e2e8540..01ba92c 100644
--- a/test/test_precedence_of.ml
+++ b/test/test_precedence_of.ml
@@ -375,8 +375,18 @@ let test_vigil_feast_is_always_none () =
    rather than a hand-made fiction. *)
 let occupant d = (Rite_of.Temporal_of.temporal d).Temporal.office
 
+(* W6 (of-known-wrongs, 2026-08-26): this used to carry the placeholder slug
+   "of-annunciation" -- the very bug precedence_of.ml's own [annunciation_
+   slug] carried, so this synthetic candidate coincidentally matched the
+   bug rather than testing against it. Now the REAL shipped slug
+   (data/of/calendar-2002.sexp: "annunciation-of-the-lord"), so the tests
+   below that use it (Rule 1/n. 60) actually exercise Rule 1 against the
+   slug production code now checks -- see
+   [test_annunciation_rule1_actually_fires] below for the test that tells
+   "Rule 1 fired" apart from "Rule 3 happened to agree", which none of
+   these did before it. *)
 let annunciation =
-  mk ~subject:Subject.Lord ~slug:"of-annunciation" ~rank:Vocab_of.Sollemnitas
+  mk ~subject:Subject.Lord ~slug:"annunciation-of-the-lord" ~rank:Vocab_of.Sollemnitas
     ~origin:Precedence.Sanctoral ()
 
 let iso s = Date.of_iso8601 s |> Result.get_ok
@@ -524,6 +534,62 @@ let test_all_souls_beats_an_ordinary_sunday () =
   Alcotest.(check bool) "All Souls, not the Sunday, is observed" true
     (resolution.Precedence.observed = all_souls_candidate)
 
+(* W6 (of-known-wrongs, 2026-08-26). [annunciation_slug] used to read
+   "of-annunciation", a placeholder that never matched the real shipped
+   entry -- Rule 1 (Normae n. 60's fixed Easter+8 destination) was DEAD
+   CODE, only ever exercised by this file's own synthetic candidate, which
+   happened to carry the identical placeholder. Every test above this one
+   proves nothing about whether Rule 1 fires against real data: they all
+   land on Easter+8, but Rule 3's general forward search converges on the
+   IDENTICAL date whenever the 3-9 April window is empty of anything at
+   Tabula entries 1-8 (true on the shipped universal calendar), so the
+   output is the same whichever rule actually answers.
+
+   This test tells the two apart. It loads the REAL shipped
+   "annunciation-of-the-lord" entry (not a synthetic reconstruction, the
+   same discipline [test_all_souls_beats_an_ordinary_sunday] above uses)
+   and RIGS the [occupant] callback to occupy Easter+8 itself with a
+   synthetic Tabula-entry-3 candidate (band 30, well inside entries 1-8).
+   Rule 3's search, if it were what answered, would have to step past that
+   occupied day onto Easter+9 -- confirmed by a CONTROL case, a different
+   solemnity on the same origin and the same rig, which can only reach
+   Rule 3 (it is neither the Annunciation nor St Joseph on Palm Sunday) and
+   does indeed land on Easter+9. Rule 1's own fixed computation never
+   consults [occupant] at all, so the rig has no effect on it: the real
+   Annunciation still landing on Easter+8 DESPITE the block is something
+   only Rule 1 firing can explain. *)
+let test_annunciation_rule1_actually_fires () =
+  let path = "../data/of/calendar-2002.sexp" in
+  let l =
+    match Colitur_kernel.Layer.load Vocab_of.rank_of_sexp path with
+    | Ok l -> l
+    | Error e -> Alcotest.failf "%s: failed to load: %s" path e
+  in
+  let annunciation_real =
+    match Colitur_kernel.Layer.find l (Slug.of_string_exn "annunciation-of-the-lord") with
+    | Some e -> { Precedence.cel = e.Colitur_kernel.Layer.cel; origin = Precedence.Sanctoral }
+    | None -> Alcotest.fail "\"annunciation-of-the-lord\" not found in the shipped calendar"
+  in
+  (* 2027: Easter 28 March, so 25 March is Holy Thursday -- inside Holy
+     Week -- and Easter+8 is 5 April, the date this rig occupies. *)
+  let origin = iso "2027-03-25" in
+  let blocked = iso "2027-04-05" in
+  let rigged d =
+    if Date.compare d blocked = 0 then
+      mk_cel ~slug:"of-w6-synthetic-blocker" ~rank:Vocab_of.Sollemnitas ()
+    else occupant d
+  in
+  let control =
+    mk ~slug:"of-w6-control" ~rank:Vocab_of.Sollemnitas ~origin:Precedence.Sanctoral () in
+  let control_target = Rite_of.Precedence_of.transfer_target control origin rigged in
+  Alcotest.(check string)
+    "control (not the Annunciation, not St Joseph): the rig really blocks -- pushed past 5 April to 6 April"
+    "2027-04-06" (Date.to_iso8601 control_target);
+  let target = Rite_of.Precedence_of.transfer_target annunciation_real origin rigged in
+  Alcotest.(check string)
+    "the REAL shipped Annunciation still lands on Easter+8 despite the block -- Rule 1, not Rule 3, fired"
+    "2027-04-05" (Date.to_iso8601 target)
+
 (* W3 (of-known-wrongs, 2026-08-26). Mary, Mother of the Church (Easter+50)
    and a fixed obligatory memorial (e.g. Anthony of Padua, 13 June) both
    used to band at Tabula III.10 (100) whenever they coincide -- a tie
@@ -605,6 +671,9 @@ let suite =
         "fix round 2: shipped All Souls beats an ordinary per-annum Sunday (2025-11-02)" `Quick
         test_all_souls_beats_an_ordinary_sunday;
       Alcotest.test_case
+        "W6: the REAL shipped Annunciation slug makes Rule 1 fire (not merely agree with Rule 3)" `Quick
+        test_annunciation_rule1_actually_fires;
+      Alcotest.test_case
         "W3: a movable BVM obligatory memorial beats a fixed one, per the CDWDS's 24 March 2018 \
          Notification" `Quick
         test_movable_bvm_memorial_beats_a_fixed_one ]