Merge pull request #46623 from nextcloud/fix/issue-44127

fix(caldav): fixed initial sync and double processing

2 files changed, 109 insertions, 10 deletions

diff --git a/apps/dav/tests/unit/CalDAV/AbstractCalDavBackend.php b/apps/dav/tests/unit/CalDAV/AbstractCalDavBackend.php
index de0684d1320..a7ca36ba994 100644
--- a/apps/dav/tests/unit/CalDAV/AbstractCalDavBackend.php
+++ b/apps/dav/tests/unit/CalDAV/AbstractCalDavBackend.php
@@ -207,6 +207,33 @@ EOD;
 		return $uri0;
 	}
 
+	protected function modifyEvent($calendarId, $objectId, $start = '20130912T130000Z', $end = '20130912T140000Z') {
+		$randomPart = self::getUniqueID();
+
+		$calData = <<<EOD
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:ownCloud Calendar
+BEGIN:VEVENT
+CREATED;VALUE=DATE-TIME:20130910T125139Z
+UID:47d15e3ec8-$randomPart
+LAST-MODIFIED;VALUE=DATE-TIME:20130910T125139Z
+DTSTAMP;VALUE=DATE-TIME:20130910T125139Z
+SUMMARY:Test Event
+DTSTART;VALUE=DATE-TIME:$start
+DTEND;VALUE=DATE-TIME:$end
+CLASS:PUBLIC
+END:VEVENT
+END:VCALENDAR
+EOD;
+
+		$this->backend->updateCalendarObject($calendarId, $objectId, $calData);
+	}
+
+	protected function deleteEvent($calendarId, $objectId) {
+		$this->backend->deleteCalendarObject($calendarId, $objectId);
+	}
+
 	protected function assertAcl($principal, $privilege, $acl) {
 		foreach ($acl as $a) {
 			if ($a['principal'] === $principal && $a['privilege'] === $privilege) {
diff --git a/apps/dav/tests/unit/CalDAV/CalDavBackendTest.php b/apps/dav/tests/unit/CalDAV/CalDavBackendTest.php
index 94d55336444..1656996408e 100644
--- a/apps/dav/tests/unit/CalDAV/CalDavBackendTest.php
+++ b/apps/dav/tests/unit/CalDAV/CalDavBackendTest.php
@@ -468,19 +468,91 @@ EOD;
 		];
 	}
 
-	public function testSyncSupport(): void {
-		$calendarId = $this->createTestCalendar();
+	public function testCalendarSynchronization(): void {
 
-		// fist call without synctoken
-		$changes = $this->backend->getChangesForCalendar($calendarId, '', 1);
-		$syncToken = $changes['syncToken'];
+		// construct calendar for testing
+		$calendarId = $this->createTestCalendar();
 
-		// add a change
-		$event = $this->createEvent($calendarId, '20130912T130000Z', '20130912T140000Z');
+		/** test fresh sync state with NO events in calendar */
+		// construct test state
+		$stateTest = ['syncToken' => 1, 'added' => [], 'modified' => [], 'deleted' => []];
+		// retrieve live state
+		$stateLive = $this->backend->getChangesForCalendar($calendarId, '', 1);
+		// test live state
+		$this->assertEquals($stateTest, $stateLive, 'Failed test fresh sync state with NO events in calendar');
+
+		/** test delta sync state with NO events in calendar */
+		// construct test state
+		$stateTest = ['syncToken' => 1, 'added' => [], 'modified' => [], 'deleted' => []];
+		// retrieve live state
+		$stateLive = $this->backend->getChangesForCalendar($calendarId, '2', 1);
+		// test live state
+		$this->assertEquals($stateTest, $stateLive, 'Failed test delta sync state with NO events in calendar');
+
+		/** add events to calendar */
+		$event1 = $this->createEvent($calendarId, '20240701T130000Z', '20240701T140000Z');
+		$event2 = $this->createEvent($calendarId, '20240701T140000Z', '20240701T150000Z');
+		$event3 = $this->createEvent($calendarId, '20240701T150000Z', '20240701T160000Z');
+
+		/** test fresh sync state with events in calendar */
+		// construct expected state
+		$stateTest = ['syncToken' => 4, 'added' => [$event1, $event2, $event3], 'modified' => [], 'deleted' => []];
+		sort($stateTest['added']);
+		// retrieve live state
+		$stateLive = $this->backend->getChangesForCalendar($calendarId, '', 1);
+		// sort live state results
+		sort($stateLive['added']);
+		sort($stateLive['modified']);
+		sort($stateLive['deleted']);
+		// test live state
+		$this->assertEquals($stateTest, $stateLive, 'Failed test fresh sync state with events in calendar');
+
+		/** test delta sync state with events in calendar */
+		// construct expected state
+		$stateTest = ['syncToken' => 4, 'added' => [$event2, $event3], 'modified' => [], 'deleted' => []];
+		sort($stateTest['added']);
+		// retrieve live state
+		$stateLive = $this->backend->getChangesForCalendar($calendarId, '2', 1);
+		// sort live state results
+		sort($stateLive['added']);
+		sort($stateLive['modified']);
+		sort($stateLive['deleted']);
+		// test live state
+		$this->assertEquals($stateTest, $stateLive, 'Failed test delta sync state with events in calendar');
+		
+		/** modify/delete events in calendar */
+		$this->deleteEvent($calendarId, $event1);
+		$this->modifyEvent($calendarId, $event2, '20250701T140000Z', '20250701T150000Z');
+
+		/** test fresh sync state with modified/deleted events in calendar */
+		// construct expected state
+		$stateTest = ['syncToken' => 6, 'added' => [$event2, $event3], 'modified' => [], 'deleted' => []];
+		sort($stateTest['added']);
+		// retrieve live state
+		$stateLive = $this->backend->getChangesForCalendar($calendarId, '', 1);
+		// sort live state results
+		sort($stateLive['added']);
+		sort($stateLive['modified']);
+		sort($stateLive['deleted']);
+		// test live state
+		$this->assertEquals($stateTest, $stateLive, 'Failed test fresh sync state with modified/deleted events in calendar');
+
+		/** test delta sync state with modified/deleted events in calendar */
+		// construct expected state
+		$stateTest = ['syncToken' => 6, 'added' => [$event3], 'modified' => [$event2], 'deleted' => [$event1]];
+		// retrieve live state
+		$stateLive = $this->backend->getChangesForCalendar($calendarId, '3', 1);
+		// test live state
+		$this->assertEquals($stateTest, $stateLive, 'Failed test delta sync state with modified/deleted events in calendar');
+
+		/** test delta sync state with modified/deleted events in calendar and invalid token */
+		// construct expected state
+		$stateTest = ['syncToken' => 6, 'added' => [], 'modified' => [], 'deleted' => []];
+		// retrieve live state
+		$stateLive = $this->backend->getChangesForCalendar($calendarId, '6', 1);
+		// test live state
+		$this->assertEquals($stateTest, $stateLive, 'Failed test delta sync state with modified/deleted events in calendar and invalid token');
 
-		// look for changes
-		$changes = $this->backend->getChangesForCalendar($calendarId, $syncToken, 1);
-		$this->assertEquals($event, $changes['added'][0]);
 	}
 
 	public function testPublications(): void {