From 6abc243e5d40bd60174a3fb1affc9517b0ac5617 Mon Sep 17 00:00:00 2001 From: Lukasz Kasprzak Date: Wed, 19 Aug 2026 09:09:36 +0200 Subject: feat(render): iCalendar emitter, RFC 5545 Not a template job: folding, escaping, exclusive DTEND and stable UIDs are rules a logic-less template cannot enforce, and each fails silently in a subscriber's client rather than loudly at generation. DTEND is EXCLUSIVE for an all-day event (section 3.6.1). Wrong here shows every event a day short, everywhere. UIDs are YYYYMMDD-@colitur and stable across regenerations (section 3.8.4.7). Wrong here duplicates the whole year in every subscriber's phone, months later. Every line is CRLF-terminated and folded at 75 octets (section 3.1). No RRULE: a liturgical calendar is not a recurrence rule. Asserted, so nobody optimises it later. DTSTAMP is a parameter, not a clock read. RFC 5545 requires it and the obvious implementation reads the wall clock -- which violates the kernel's determinism rule and would make two feeds from identical data differ byte-for-byte, defeating reproducible builds and any reviewable diff on a published tree. Corrected one test literal against real engine output: DTSTAMP is a per-VEVENT property (section 3.8.7.2), not calendar-level, so the default-value line count is 365 (every event), not 1. Mutation-tested: a non-exclusive DTEND reddens the suite. --- test/test_ics.ml | 100 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 100 insertions(+) create mode 100644 test/test_ics.ml (limited to 'test/test_ics.ml') diff --git a/test/test_ics.ml b/test/test_ics.ml new file mode 100644 index 0000000..ac0c9ee --- /dev/null +++ b/test/test_ics.ml @@ -0,0 +1,100 @@ +module Ics = Colitur_render.Emit_ics + +let out_2027 () = Ics.year (Test_view.view_of 2027) + +let lines s = + String.split_on_char '\n' s + |> List.map (fun l -> if l <> "" && l.[String.length l - 1] = '\r' then String.sub l 0 (String.length l - 1) else l) + |> List.filter (fun l -> l <> "") + +let count_prefix p ls = + List.length (List.filter (fun l -> String.length l >= String.length p && String.sub l 0 (String.length p) = p) ls) + +let test_envelope () = + let ls = lines (out_2027 ()) in + Alcotest.(check string) "first line" "BEGIN:VCALENDAR" (List.hd ls); + Alcotest.(check string) "last line" "END:VCALENDAR" (List.nth ls (List.length ls - 1)); + Alcotest.(check int) "version" 1 (count_prefix "VERSION:2.0" ls); + Alcotest.(check int) "prodid" 1 (count_prefix "PRODID:" ls); + Alcotest.(check int) "365 events" 365 (count_prefix "BEGIN:VEVENT" ls) + +(* RFC 5545 section 3.6.1: for an all-day event DTEND is EXCLUSIVE. Getting + this wrong shows every event a day short in every client. *) +let test_dtend_is_exclusive () = + let ls = lines (out_2027 ()) in + let starts = List.filter_map (fun l -> + if count_prefix "DTSTART;VALUE=DATE:" [l] = 1 then + Some (String.sub l (String.length "DTSTART;VALUE=DATE:") 8) else None) ls in + let ends = List.filter_map (fun l -> + if count_prefix "DTEND;VALUE=DATE:" [l] = 1 then + Some (String.sub l (String.length "DTEND;VALUE=DATE:") 8) else None) ls in + Alcotest.(check int) "same count" (List.length starts) (List.length ends); + Alcotest.(check string) "1 Jan starts" "20270101" (List.hd starts); + Alcotest.(check string) "1 Jan ends on the 2nd" "20270102" (List.hd ends); + Alcotest.(check string) "31 Dec ends on 1 Jan next" "20280101" + (List.nth ends (List.length ends - 1)) + +let test_uids_unique_and_shaped () = + let ls = lines (out_2027 ()) in + let uids = List.filter_map (fun l -> + if count_prefix "UID:" [l] = 1 then Some (String.sub l 4 (String.length l - 4)) else None) ls in + Alcotest.(check int) "365 uids" 365 (List.length uids); + let sorted = List.sort_uniq String.compare uids in + Alcotest.(check int) "all unique" 365 (List.length sorted); + Alcotest.(check string) "shape" "20270101-ef@colitur" (List.hd uids) + +(* The rule that punishes silently, months later, in someone else's phone: + regenerating a feed must not duplicate every event. *) +let test_output_is_byte_stable_across_runs () = + Alcotest.(check string) "two runs identical" (out_2027 ()) (out_2027 ()) + +let test_every_line_folded_and_crlf () = + let raw = out_2027 () in + List.iter + (fun l -> + if String.length l > 75 then Alcotest.failf "line of %d octets: %s" (String.length l) l) + (lines raw); + (* Every physical line ends CRLF (RFC 5545 section 3.1). *) + let n = String.length raw in + let rec check i = + if i >= n then () + else if raw.[i] = '\n' then ( + if i = 0 || raw.[i - 1] <> '\r' then Alcotest.failf "bare LF at offset %d" i; + check (i + 1)) + else check (i + 1) + in + check 0 + +let test_no_rrule () = + Alcotest.(check int) "no RRULE" 0 (count_prefix "RRULE" (lines (out_2027 ()))) + +let test_text_escaped () = + let ls = lines (Ics.year (Test_view.view_of 2035)) in + (* 2035-04-03 is St Joseph, whose English name contains a comma. *) + let joseph = List.find (fun l -> count_prefix "SUMMARY:St. Joseph" [l] = 1) ls in + Alcotest.(check bool) "comma escaped" true + (let re = "\\," in + let n = String.length re in + let rec f i = i + n <= String.length joseph && (String.sub joseph i n = re || f (i + 1)) in + f 0) + +let test_dtstamp_is_a_parameter () = + let a = Ics.year ~dtstamp:"20200101T000000Z" (Test_view.view_of 2027) in + let b = Ics.year ~dtstamp:"20210101T000000Z" (Test_view.view_of 2027) in + Alcotest.(check bool) "differs with the parameter" true (a <> b); + (* DTSTAMP is a per-VEVENT property (RFC 5545 section 3.8.7.2), not a + calendar-level one -- every one of the 365 events carries the same + default value, not just one line in the whole feed. *) + Alcotest.(check int) "default is deterministic" 365 + (count_prefix "DTSTAMP:20270101T000000Z" (lines (out_2027 ()))) + +let suite = + ( "Emit/ics", + [ Alcotest.test_case "envelope" `Quick test_envelope; + Alcotest.test_case "DTEND exclusive" `Quick test_dtend_is_exclusive; + Alcotest.test_case "uids unique and shaped" `Quick test_uids_unique_and_shaped; + Alcotest.test_case "byte-stable across runs" `Quick test_output_is_byte_stable_across_runs; + Alcotest.test_case "folded and CRLF" `Quick test_every_line_folded_and_crlf; + Alcotest.test_case "no RRULE" `Quick test_no_rrule; + Alcotest.test_case "text escaped" `Quick test_text_escaped; + Alcotest.test_case "DTSTAMP is a parameter" `Quick test_dtstamp_is_a_parameter ] ) -- cgit v1.3