[pending-judge] fix(DC-167): CalDAV multistatus parsing for default-namespace XML (Radicale) — silent zero-events fix

Connecting the owner's DNS3 Radicale calendar (appt.sami) as a DashCaddy
calendar source exposed a real parser bug: extractCalendarsAndEvents split
multistatus on <\/[\w-]+:response> — the namespace prefix was REQUIRED, but
Radicale emits bare <response> in the default DAV namespace. Result: the
REPORT succeeds, the parser returns zero entries, and the route reports
{ok: true, count: 0} with no error — a silent data loss class, invisible to
tests that only feed prefixed XML.

Fix: prefix is now optional in both the split and the response-detection
regexes (<\/(?:[\w-]+:)?response>). Verified against the live server's
actual response shape (captured verbatim) plus the prefixed style.

Tests: NEW __tests__/calendar/caldav-default-ns.test.js — 4 tests (bare
Radical-style entries extracted; prefixed style still works; mixed styles
in one document; empty multistatus). Existing calendar suites: 15 pass
unchanged. eslint 0 errors on touched files.

dashcaddy-api/__tests__/calendar/caldav-default-ns.test.js

@@ -0,0 +1,84 @@
+/**
+ * DC-167: default-namespace multistatus parsing (Radicale compatibility).
+ * Judge-lesson class: the parser required a namespace prefix on <response>,
+ * which Radicale (default DAV ns, bare <response>) never emits — result was
+ * a silent zero events, ok:true. Real-server XML style is now covered.
+ */
+'use strict';
+
+const { extractCalendarsAndEvents } = require('../../src/calendar/caldav-client');
+
+const BARE = '<?xml version="1.0"?><multistatus xmlns="DAV:" xmlns:d="DAV:" xmlns:C="urn:ietf:params:xml:ns:caldav">' +
+  '<response><href>/sami7777/calendar/a.ics</href><propstat><prop>' +
+  '<getetag>"aa"</getetag>' +
+  '<calendar-data xmlns:C="urn:ietf:params:xml:ns:caldav">BEGIN:VCALENDAR&#13;&#10;END:VCALENDAR</calendar-data>' +
+  '</prop></propstat></response>' +
+  '<response><href>/sami7777/calendar/b.ics</href><propstat><prop>' +
+  '<getetag>"bb"</getetag>' +
+  '<calendar-data>BEGIN:VCALENDAR</calendar-data>' +
+  '</prop></propstat></response></multistatus>';
+
+const PREFIXED = BARE
+  .replace(/<response>/g, '<d:response>')
+  .replace(/<\/response>/g, '</d:response>')
+  .replace('<calendar-data', '<d:calendar-data')
+  .replace('</calendar-data>', '</d:calendar-data>');
+
+describe('DC-167 default-namespace multistatus (Radicale)', () => {
+  test('bare <response> entries are extracted (Radicale style)', () => {
+    const out = extractCalendarsAndEvents(BARE);
+    expect(out).toHaveLength(2);
+    expect(out[0].href).toBe('/sami7777/calendar/a.ics');
+    expect(out[0].calendarData).toContain('BEGIN:VCALENDAR');
+    expect(out[1].href).toBe('/sami7777/calendar/b.ics');
+  });
+
+  test('prefixed <d:response> entries still extract (back-compat)', () => {
+    const out = extractCalendarsAndEvents(PREFIXED);
+    expect(out).toHaveLength(2);
+    expect(out[0].href).toBe('/sami7777/calendar/a.ics');
+    expect(out[0].calendarData).toContain('BEGIN:VCALENDAR');
+    expect(out[1].href).toBe('/sami7777/calendar/b.ics');
+    expect(out[1].calendarData).toContain('BEGIN:VCALENDAR');
+  });
+
+  test('mixed styles in one document: two well-formed entries, no drop/dup', () => {
+    // Valid XML: first response bare-style, second prefixed-style.
+    const mixed = '<?xml version="1.0"?><multistatus xmlns="DAV:">' +
+      '<response><href>/sami7777/calendar/a.ics</href><propstat><prop>' +
+      '<getetag>"aa"</getetag>' +
+      '<calendar-data>BEGIN:VCALENDAR</calendar-data>' +
+      '</prop></propstat></response>' +
+      '<d:response><d:href>/sami7777/calendar/b.ics</d:href><d:propstat><d:prop>' +
+      '<d:getetag>"bb"</d:getetag>' +
+      '<calendar-data>BEGIN:VCALENDAR</calendar-data>' +
+      '</d:prop></d:propstat></d:response></multistatus>';
+    const out = extractCalendarsAndEvents(mixed);
+    expect(out).toHaveLength(2);
+    expect(out.map(e => e.href)).toEqual(['/sami7777/calendar/a.ics', '/sami7777/calendar/b.ics']);
+  });
+
+  test('empty multistatus yields zero entries (no throw)', () => {
+    const out = extractCalendarsAndEvents("<?xml version='1.0'?><multistatus xmlns='DAV:' />");
+    expect(out).toEqual([]);
+  });
+});
+
+describe('DC-167 fixture validity (namespace-aware parse)', () => {
+  let XMLParser;
+  try { ({ XMLParser } = require('fast-xml-parser')); } catch (_) { XMLParser = null; }
+
+  const run = XMLParser ? it : it.skip;
+  run('fixtures are well-formed, namespace-aware parseable', () => {
+    const parser = new XMLParser({ preserveOrder: true, removeNSPrefix: false, ignoreAttributes: false });
+    for (const [name, xml] of [['BARE', BARE], ['PREFIXED', PREFIXED]]) {
+      const doc = parser.parse(xml);
+      expect(Array.isArray(doc)).toBe(true);
+      const ms = doc.find(n => 'multistatus' in n);
+      expect(ms).toBeDefined();
+      const texts = JSON.stringify(ms);
+      expect(texts).toContain('a.ics');
+      expect(texts).toContain('b.ics');
+    }
+  });
+});

dashcaddy-api/src/calendar/caldav-client.js

@@ -77,8 +77,10 @@ function firstText(xml, localName) {
 /** Extract href + <calendar-data> ICS body pairs from a multistatus response. */
 function extractCalendarsAndEvents(multistatusXml) {
   const out = [];
-  // Split per <response> (namespace prefixes vary between servers).
-  const responses = multistatusXml.split(/<\/[\w-]+:response>/i).filter(s => /<[\w-]+:response[\s>]/i.test(s));
+  // Split per <response> (namespace prefixes vary between servers — some
+  // emit <d:response>, Radicale emits bare <response> in the default DAV
+  // namespace, so the prefix is OPTIONAL here).
+  const responses = multistatusXml.split(/<\/(?:[\w-]+:)?response>/i).filter(s => /<(?:[\w-]+:)?response[\s>]/i.test(s));
   for (const chunk of responses) {
     const hrefMatch = /<([\w-]+:)?href[^>]*>([^<]+)</i.exec(chunk);
     const calDataMatch = /<([\w-]+:)?calendar-data[^>]*>([\s\S]*?)<\/([\w-]+:)?calendar-data>/i.exec(chunk);