feat(lang): Latin temporal names from the Missal

Every entry is transcribed from the 1962 Missal's own propers headings in
docs/research/LT.txt and cites where it came from; names constructed by
following a neighbouring pattern are marked as such, so a reader can tell
transcription from inference.

The coverage test is the point of this commit. It walks every day of
2020-2045 and fails naming any slug with no Latin name -- the test that
would have caught the original defect, where a printed booklet said
ef-septuagesima-sunday-2 because nothing asserted that names exist.

The three Triduum names reuse the exact strings temporal_ef.ml already
carries, so the engine and the language file cannot disagree.

3 files changed, 75 insertions, 0 deletions

diff --git a/test/dune b/test/dune
index b9cc2a7..6e2ac87 100644
--- a/test/dune
+++ b/test/dune
@@ -4,6 +4,7 @@
  (deps
   ../data/ef/sanctoral.sexp
   ../data/ef/adjustments.sexp
+  ../lang/la.ini
   ../data/ef/expected-divergences.sexp
   ../data/ef/expected-divergences-missalemeum.sexp
   ../data/ef/lectionary.sexp
diff --git a/test/test_colitur.ml b/test/test_colitur.ml
index 1c445a6..1bdd220 100644
--- a/test/test_colitur.ml
+++ b/test/test_colitur.ml
@@ -3,6 +3,7 @@ let () =
   Alcotest.run "colitur"
     [ Test_date.suite; Test_computus.suite; Test_colour.suite; Test_slug.suite; Test_names.suite;
       Test_lang.suite;
+      Test_lang_coverage.suite;
       Test_config.suite;
       Test_overlay.suite; Test_overlay_ini.suite; Test_temporal_ef.suite; Test_validate.suite; Test_precedence.suite;
       Test_calendar.suite; Test_precedence_ef.suite; Test_sanctoral_ef.suite; Test_rite_ef.suite;
diff --git a/test/test_lang_coverage.ml b/test/test_lang_coverage.ml
new file mode 100644
index 0000000..d72484f
--- /dev/null
+++ b/test/test_lang_coverage.ml
@@ -0,0 +1,73 @@
+module L = Colitur_naming.Lang
+
+let read path =
+  let ic = open_in_bin path in
+  let s = really_input_string ic (in_channel_length ic) in
+  close_in ic;
+  s
+
+let la () =
+  match L.of_string (read "../lang/la.ini") with
+  | Ok t -> t
+  | Error e -> Alcotest.failf "lang/la.ini: %s" e
+
+(* Every TEMPORAL slug the engine can emit must have a Latin name. THIS IS THE
+   TEST THAT WOULD HAVE CAUGHT THE ORIGINAL DEFECT -- a booklet printed
+   "ef-septuagesima-sunday-2" because nothing asserted coverage. It must fail
+   loudly the moment a new slug appears without a name.
+
+   RESTRICTED TO "^ef-" SLUGS FOR NOW (Task 3's own scope: la.ini's
+   [celebration] table currently carries the temporal half only). Task 4 adds
+   the sanctoral names and REMOVES this filter -- see this file's own
+   [is_temporal_slug] below, kept as one clearly-named, easy-to-find place to
+   change, rather than an inline condition. *)
+let is_temporal_slug slug = String.length slug >= 3 && String.sub slug 0 3 = "ef-"
+
+let test_every_temporal_slug_has_a_latin_name () =
+  let t = la () in
+  let layer = match Test_support.load_ef_layer () with Ok l -> l | Error e -> Alcotest.failf "%s" e in
+  let ctx = Test_support.ef_context () in
+  let missing = ref [] in
+  for y = 2020 to 2045 do
+    Array.iter
+      (fun (d : (Rite_ef.Vocab_ef.season, Rite_ef.Vocab_ef.rank) Colitur_kernel.Liturgical_day.t) ->
+        let slug =
+          Colitur_kernel.Slug.to_string
+            d.Colitur_kernel.Liturgical_day.observed.Colitur_kernel.Celebration.slug
+        in
+        (* A miss returns the key itself, so name = slug means "no entry". *)
+        if
+          is_temporal_slug slug
+          && L.celebration t slug = slug
+          && not (List.mem slug !missing)
+        then missing := slug :: !missing)
+      (Colitur_kernel.Calendar.year ctx layer y)
+  done;
+  if !missing <> [] then
+    Alcotest.failf "%d slugs have no Latin name, e.g. %s" (List.length !missing)
+      (String.concat ", " (List.filteri (fun i _ -> i < 5) !missing))
+
+let test_vocabularies_are_complete () =
+  let t = la () in
+  List.iter
+    (fun s -> if L.season t s = s then Alcotest.failf "no Latin season name for %S" s)
+    [ "advent"; "christmastide"; "time-after-epiphany"; "septuagesima"; "lent";
+      "passiontide"; "paschaltide"; "time-after-pentecost" ];
+  List.iter
+    (fun r -> if L.rank t r = r then Alcotest.failf "no Latin rank name for %S" r)
+    [ "class-1"; "class-2"; "class-3"; "class-4" ];
+  List.iter
+    (fun c -> if L.colour t c = c then Alcotest.failf "no Latin colour name for %S" c)
+    [ "white"; "red"; "green"; "violet"; "rose"; "black" ];
+  for n = 0 to 6 do
+    if L.weekday t n = string_of_int n then Alcotest.failf "no Latin weekday for %d" n
+  done;
+  for n = 1 to 12 do
+    if L.month t n = string_of_int n then Alcotest.failf "no Latin month for %d" n
+  done
+
+let suite =
+  ( "Lang/coverage",
+    [ Alcotest.test_case "every temporal slug has a Latin name" `Slow
+        test_every_temporal_slug_has_a_latin_name;
+      Alcotest.test_case "vocabularies complete" `Quick test_vocabularies_are_complete ] )