Filter on last user modified (#8093)

Example: `userdate:PT1H` to select only articles modified by user during the last hour
Fix https://github.com/FreshRSS/FreshRSS/issues/4280#issuecomment-3393078024

Useful for instance to bulk mark as unread recently marked articles by error:
1. Click on the toggle button to show the read articles (making sure the toggle for the unread articles is off)
2. Sort by *User modified 9→1*
3. Filter by *user modified date*, for instance to the last 3 hours by typing `userdate:PT3H`
4. Click in the drop-down menu *Mark selection as unread*

P.S.: I have added at the same time a bunch of unit tests for date-related logic

1 files changed, 84 insertions, 0 deletions

diff --git a/tests/lib/LibDateTest.php b/tests/lib/LibDateTest.php
new file mode 100644
index 000000000..0c07696f5
--- /dev/null
+++ b/tests/lib/LibDateTest.php
@@ -0,0 +1,84 @@
+<?php
+declare(strict_types=1);
+
+require_once LIB_PATH . '/lib_date.php';
+
+use PHPUnit\Framework\Attributes\DataProvider;
+
+/**
+ * Tests for lib_date.php functions
+ */
+class LibDateTest extends \PHPUnit\Framework\TestCase {
+
+	/**
+	 * Test parseDateInterval function with various ISO 8601 interval formats
+	 *
+	 * @param string $interval
+	 * @param int|null|false $expectedMin
+	 * @param int|null|false $expectedMax
+	 */
+	#[DataProvider('provideDateIntervals')]
+	public function test_parseDateInterval(string $interval, $expectedMin, $expectedMax): void {
+		$result = parseDateInterval($interval);
+		self::assertIsArray($result);
+		self::assertCount(2, $result);
+		self::assertSame($expectedMin, $result[0], "Min timestamp mismatch for interval: $interval");
+		self::assertSame($expectedMax, $result[1], "Max timestamp mismatch for interval: $interval");
+	}
+
+	/** @return list<array{string,int|null|false,int|null|false}> */
+	public static function provideDateIntervals(): array {
+		return [
+			['', null, null], // Empty string
+
+			// Year intervals
+			['2014', strtotime('2014-01-01 00:00:00'), strtotime('2014-12-31 23:59:59')],
+			[' 2015 ', strtotime('2015-01-01 00:00:00'), strtotime('2015-12-31 23:59:59')],	// With whitespace to be trimmed
+
+			// Year-month intervals
+			['2014-03', strtotime('2014-03-01 00:00:00'), strtotime('2014-03-31 23:59:59')],
+			['2016-02', strtotime('2016-02-01 00:00:00'), strtotime('2016-02-29 23:59:59')],	// Leap year
+			['2014-02', strtotime('2014-02-01 00:00:00'), strtotime('2014-02-28 23:59:59')],	// Non-leap year
+			['201404', strtotime('2014-04-01 00:00:00'), strtotime('2014-04-30 23:59:59')],	// Without hyphen
+
+			// Specific dates
+			['2014-03-30', strtotime('2014-03-30 00:00:00'), strtotime('2014-03-30 23:59:59')],
+			['2014-05-30T13', strtotime('2014-05-30 13:00:00'), strtotime('2014-05-30 13:59:59')],
+			['2014-05-30T13:30', strtotime('2014-05-30 13:30:00'), strtotime('2014-05-30 13:30:59')],
+
+			// Date ranges with explicit end dates
+			['2014-02/2014-04', strtotime('2014-02-01 00:00:00'), strtotime('2014-04-30 23:59:59')],
+			['2014-02--2014-04', strtotime('2014-02-01 00:00:00'), strtotime('2014-04-30 23:59:59')],	// Same with -- separator
+			['2014-02/04', strtotime('2014-02-01 00:00:00'), strtotime('2014-04-30 23:59:59')],
+			['2014-02-03/05', strtotime('2014-02-03 00:00:00'), strtotime('2014-02-05 23:59:59')],
+
+			// Time ranges within same day
+			['2014-02-03T22:00/22:15', strtotime('2014-02-03 22:00:00'), strtotime('2014-02-03 22:15:59')],
+			['2014-02-03T22:00/15', strtotime('2014-02-03 22:00:00'), strtotime('2014-02-03 22:15:59')],
+
+			// Open intervals
+			['2014-03/', strtotime('2014-03-01 00:00:00'), null],
+			['/2014-03', null, strtotime('2014-03-31 23:59:59')],
+
+			// Period-based intervals
+			['2014-03/P1W', strtotime('2014-03-01 00:00:00'), strtotime('2014-03-07 23:59:59')],
+			['P1W/2014-05-25T23:59:59', strtotime('2014-05-19 00:00:00'), strtotime('2014-05-25 23:59:59')],
+
+			// Fixed date periods with known anchors
+			['2014-01-01/P1Y', strtotime('2014-01-01 00:00:00'), strtotime('2014-12-31 23:59:59')],
+			['2014-06-15/P6M', strtotime('2014-06-15 00:00:00'), strtotime('2014-12-14 23:59:59')],
+			['2014-03-01/P2W', strtotime('2014-03-01 00:00:00'), strtotime('2014-03-14 23:59:59')],
+			['2014-12-25/P10D', strtotime('2014-12-25 00:00:00'), strtotime('2015-01-03 23:59:59')],
+			['2014-01-01T12:00/PT6H', strtotime('2014-01-01 12:00:00'), strtotime('2014-01-01 17:59:59')],
+			['2014-01-01 12:00/PT6H', strtotime('2014-01-01 12:00:00'), strtotime('2014-01-01 17:59:59')],	// Space instead of T
+			['2014-01-01T12:00/PT6h', strtotime('2014-01-01 12:00:00'), strtotime('2014-01-01 17:59:59')],	// Lowercase h
+			['2014-05-01T10:30/PT90M', strtotime('2014-05-01 10:30:00'), strtotime('2014-05-01 11:59:59')],
+			['2014-07-04T14:15:30/PT45S', strtotime('2014-07-04 14:15:30'), strtotime('2014-07-04 14:16:14')],
+
+			// Reverse periods
+			['P1M/2014-02-28', strtotime('2014-01-28 00:00:01'), strtotime('2014-02-28 00:00:00')],
+			['P3D/2014-01-10T23:59:59', strtotime('2014-01-08 00:00:00'), strtotime('2014-01-10 23:59:59')],
+			['PT12H/2014-06-01T12:00', strtotime('2014-06-01 00:00:01'), strtotime('2014-06-01 12:00:00')],
+		];
+	}
+}