Add the iCalendar round-trip

Parsing goes through icalendar's low-level parser, which keeps properties in order and keeps repeated ones. Writing is ours: that crate's writer escapes a whole property value as text, so CATEGORIES:Work,Personal would go out as one category named "Work,Personal" to every other client. Anything the model does not interpret is carried rather than dropped -- X-MOZ-LASTACK, X-EVOLUTION-ALARM-UID, ACKNOWLEDGED, the X-MICROSOFT-CDO set, unrecognised ATTENDEE parameters, and whole VTODO/VJOURNAL components. A calendar has several clients writing to it and this one is not the authority on which properties matter. VTIMEZONE is modelled properly, and TZID is stored exactly as written: Exchange names its zones "Pacific Standard Time", which no IANA lookup resolves, and normalising at parse time would make the document unrepresentable. Mapping to a real zone belongs at the point of use. Tested against a golden corpus captured from the live Baikal (seven producing clients over five years) and a published Outlook feed, scrubbed of private content with the structure left byte-for-byte. Eight hand-written fixtures cover what neither server had: DURATION, floating times, RDATE, DST boundaries, leap day, and the full escape set. The contract is that parse -> write -> parse is stable, plus a check that no property name loses occurrences across the trip, since a parser that dropped ATTENDEE entirely would round-trip perfectly and still be wrong.
2026-08-26 14:32:38 -04:00
parent 52cd5a961d
commit 7043a151f6
35 changed files with 3397 additions and 11 deletions
@@ -0,0 +1,13 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//Runway//Runway Test Fixture//EN
+BEGIN:VEVENT
+UID:allday-exdate@fixtures.runway.invalid
+DTSTAMP:20260101T000000Z
+DTSTART;VALUE=DATE:20260105
+DTEND;VALUE=DATE:20260106
+SUMMARY:Bin day
+RRULE:FREQ=WEEKLY;BYDAY=MO
+EXDATE;VALUE=DATE:20260223,20260302
+END:VEVENT
+END:VCALENDAR
@@ -0,0 +1,12 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//Runway//Runway Test Fixture//EN
+BEGIN:VEVENT
+UID:dst-spring-forward@fixtures.runway.invalid
+DTSTAMP:20260301T090000Z
+DTSTART;TZID=America/Denver:20260302T090000
+DTEND;TZID=America/Denver:20260302T093000
+SUMMARY:Weekly across spring forward
+RRULE:FREQ=WEEKLY;BYDAY=MO;COUNT=4
+END:VEVENT
+END:VCALENDAR
@@ -0,0 +1,11 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//Runway//Runway Test Fixture//EN
+BEGIN:VEVENT
+UID:duration-not-dtend@fixtures.runway.invalid
+DTSTAMP:20260114T090000Z
+DTSTART;TZID=America/Denver:20260114T090000
+DURATION:PT1H30M
+SUMMARY:Ninety minutes expressed as a duration
+END:VEVENT
+END:VCALENDAR
@@ -0,0 +1,11 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//Runway//Runway Test Fixture//EN
+BEGIN:VEVENT
+UID:floating@fixtures.runway.invalid
+DTSTAMP:20260114T090000Z
+DTSTART:20260114T090000
+DTEND:20260114T100000
+SUMMARY:Nine in the morning\, wherever you are
+END:VEVENT
+END:VCALENDAR
@@ -0,0 +1,12 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//Runway//Runway Test Fixture//EN
+BEGIN:VEVENT
+UID:leap-day@fixtures.runway.invalid
+DTSTAMP:20240229T000000Z
+DTSTART;VALUE=DATE:20240229
+DTEND;VALUE=DATE:20240301
+SUMMARY:Leap day
+RRULE:FREQ=YEARLY;BYMONTH=2;BYMONTHDAY=29
+END:VEVENT
+END:VCALENDAR
@@ -0,0 +1,14 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//Runway//Runway Test Fixture//EN
+BEGIN:VEVENT
+UID:rdate-exdate@fixtures.runway.invalid
+DTSTAMP:20260105T090000Z
+DTSTART;TZID=America/Denver:20260105T090000
+DTEND;TZID=America/Denver:20260105T093000
+SUMMARY:Weekly with an extra date and two skipped
+RRULE:FREQ=WEEKLY;BYDAY=MO;COUNT=8
+RDATE;TZID=America/Denver:20260110T090000
+EXDATE;TZID=America/Denver:20260119T090000,20260202T090000
+END:VEVENT
+END:VCALENDAR
@@ -0,0 +1,22 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//Runway//Runway Test Fixture//EN
+BEGIN:VEVENT
+UID:series-override@fixtures.runway.invalid
+DTSTAMP:20260105T090000Z
+DTSTART;TZID=America/Denver:20260105T090000
+DTEND;TZID=America/Denver:20260105T100000
+SUMMARY:Standup
+RRULE:FREQ=WEEKLY;BYDAY=MO
+SEQUENCE:0
+END:VEVENT
+BEGIN:VEVENT
+UID:series-override@fixtures.runway.invalid
+RECURRENCE-ID;TZID=America/Denver:20260119T090000
+DTSTAMP:20260112T142200Z
+DTSTART;TZID=America/Denver:20260119T140000
+DTEND;TZID=America/Denver:20260119T150000
+SUMMARY:Standup (moved to the afternoon)
+SEQUENCE:1
+END:VEVENT
+END:VCALENDAR
@@ -0,0 +1,16 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//Runway//Runway Test Fixture//EN
+BEGIN:VEVENT
+UID:escapes@fixtures.runway.invalid
+DTSTAMP:20260114T090000Z
+DTSTART;TZID=Europe/Zurich:20260114T090000
+DTEND;TZID=Europe/Zurich:20260114T100000
+SUMMARY:Lezione d'italiano — caffè\, cioccolato e “virgolette”
+DESCRIPTION:Line one\nLine two\; with a semicolon\nA backslash: \\\nA comm
+ a\, and a colon: here
+LOCATION;LANGUAGE=it-CH:Zürich\, Hauptbahnhof
+ORGANIZER;CN="Rossi, Giulia (IT: Milano)":mailto:giulia.rossi@example.org
+CATEGORIES:Lezioni,Personale
+END:VEVENT
+END:VCALENDAR