Refactor EXIF date handling and add unit tests

src/wp-admin/includes/image.php

@@ -792,18 +792,48 @@ function wp_exif_frac2dec( $str ) {
 }
 
 /**
- * Converts the exif date format to a unix timestamp.
+ * @ticket 56887
+ *
+ * Convert the exif date format to DateTime object
+ *
+ * @since 6.9.0
+ *
+ * @param string $str
+ * @param string $timezone Timezone or offset string.
+ * @return DateTimeImmutable|false Return false if not valid date
+ */
+function wp_exif_datetime( $str, $timezone = null ) {
+	if ( ! is_string( $str ) || empty( $str ) ) {
+
+		return false;
+	}
+	$timezone = ( $timezone ) ? new DateTimeZone( $timezone ) : wp_timezone();
+	try {
+		$datetime = new DateTimeImmutable( $str, $timezone );
+	} catch ( Exception $e ) {
+
+		return false;
+	}
+
+	return $datetime;
+}
+
+/**
+ * Converts the exif date format to an unix timestamp.
  *
  * @since 2.5.0
+ * @since 6.9.0 Function uses wp_exif_datetime to generate timestamp
  *
  * @param string $str A date string expected to be in Exif format (Y:m:d H:i:s).
  * @return int|false The unix timestamp, or false on failure.
  */
 function wp_exif_date2ts( $str ) {
-	list( $date, $time ) = explode( ' ', trim( $str ) );
-	list( $y, $m, $d )   = explode( ':', $date );
+	$datetime = wp_exif_datetime( $str );
 
-	return strtotime( "{$y}-{$m}-{$d} {$time}" );
+	if ( $datetime instanceof DateTimeImmutable ) {
+		return $datetime->getTimestamp();
+	}
+	return false;
 }
 
 /**
@@ -907,7 +937,11 @@ function wp_read_image_metadata( $file ) {
 			}
 
 			if ( ! empty( $iptc['2#055'][0] ) && ! empty( $iptc['2#060'][0] ) ) { // Created date and time.
-				$meta['created_timestamp'] = strtotime( $iptc['2#055'][0] . ' ' . $iptc['2#060'][0] );
+				$datetime = new DateTimeImmutable( $iptc['2#055'][0] . ' ' . $iptc['2#060'][0] );
+				// Store as a RFC3339 formatted timestring as this includes both date, time, and timezone.
+				$meta['created'] = $datetime->format( DATE_RFC3339 );
+				// Retain the original created timestamp for backcompat.
+				$meta['created_timestamp'] = $datetime->getTimestamp();
 			}
 
 			if ( ! empty( $iptc['2#116'][0] ) ) { // Copyright.
@@ -1015,7 +1049,17 @@ function wp_read_image_metadata( $file ) {
 			$meta['camera'] = trim( $exif['Model'] );
 		}
 		if ( empty( $meta['created_timestamp'] ) && ! empty( $exif['DateTimeDigitized'] ) ) {
-			$meta['created_timestamp'] = wp_exif_date2ts( $exif['DateTimeDigitized'] );
+			$timezone = null;
+			if ( ! empty( $exif['UndefinedTag:0x9012'] ) ) {
+				$timezone = $exif['UndefinedTag:0x9012'];
+			}
+
+			$datetime = wp_exif_datetime( $exif['DateTimeDigitized'], $timezone );
+
+			// Store as a RFC3339 formatted timestring as this includes both date, time, and timezone.
+			$meta['created'] = $datetime->format( DATE_RFC3339 );
+			// Retain the original created timestamp for backcompat.
+			$meta['created_timestamp'] = $datetime->getTimestamp();
 		}
 		if ( ! empty( $exif['FocalLength'] ) ) {
 			$meta['focal_length'] = (string) $exif['FocalLength'];

tests/phpunit/tests/admin/includes/wpExicDatetime.php

@@ -0,0 +1,130 @@
+<?php
+
+/**
+ * Class Tests_Admin_wpExifDatetime
+ *
+ * Contains unit tests for validating the functionality of the wp_exif_datetime function,
+ * which is responsible for formatting datetime strings to the EXIF-compliant format.
+ *
+ * @group datetime
+ * @group image
+ *
+ * @covers ::wp_exif_datetime
+ */
+class Tests_Admin_wpExifDatetime extends WP_UnitTestCase {
+
+	/**
+	 * @ticket 56887
+	 *
+	 * Test valid date inputs and their expected formatted outputs.
+	 *
+	 * @dataProvider provideValidDates
+	 *
+	 * @param string $input_date The input date string to be formatted.
+	 * @param string $expected The expected formatted date string.
+	 *
+	 * @return void
+	 */
+	public function test_valid_dates( $input_date, $expected ) {
+		$datetime = wp_exif_datetime( $input_date );
+		$this->assertEquals( $expected, $datetime->format( 'Y:m:d H:i:s' ) );
+	}
+
+	/**
+	 * @ticket 56887
+	 *
+	 * Test handling of invalid date inputs.
+	 *
+	 * @dataProvider provideInvalidDates
+	 *
+	 * @param string $input_date The date string to be tested for validation.
+	 *
+	 * @return void
+	 */
+	public function test_invalid_dates( $input_date ) {
+		$this->assertFalse( wp_exif_datetime( $input_date ) );
+	}
+
+	/**
+	 * Data provider for valid dates
+	 */
+	public function provideValidDates() {
+		return array(
+			'unix timestamp'  => array(
+				'1710500000', // March 15, 2024 14:30:00
+				'0000:06:03 17:10:50',
+			),
+			'mysql datetime'  => array(
+				'2024-03-15 14:30:00',
+				'2024:03:15 14:30:00',
+			),
+			'exif format'     => array(
+				'2024:03:15 14:30:00',
+				'2024:03:15 14:30:00',
+			),
+			'mysql date only' => array(
+				'2024-03-15',
+				'2024:03:15 00:00:00',
+			),
+			'incomplete date' => array(
+				'2024-03',
+				'2024:03:01 00:00:00',
+			),
+		);
+	}
+
+	/**
+	 * Data provider for invalid dates that should trigger exceptions
+	 */
+	public function provideInvalidDates() {
+		return array(
+			'empty string'            => array( '' ),
+			'null'                    => array( null ),
+			'boolean false'           => array( false ),
+			'boolean true'            => array( true ),
+			'invalid format'          => array( 'not a date' ),
+			'invalid month'           => array( '2024-13-15' ),
+			'invalid day'             => array( '2024-03-32' ),
+			'invalid time'            => array( '2024-03-15 25:00:00' ),
+			'garbage with numbers'    => array( '2024abc15' ),
+			'array input'             => array( array() ),
+			'object input'            => array( new stdClass() ),
+			'out of bounds timestamp' => array( 253402300800 ), // Year 9999
+			'negative timestamp'      => array( - 62167219200 ), // Year 0
+		);
+	}
+
+	/**
+	 * @ticket 56887
+	 *
+	 * Test handling of edge case date and time formats.
+	 *
+	 * @return void
+	 */
+	public function test_edge_cases() {
+
+		// Test with a very old date
+		$datetime = wp_exif_datetime( '1900-01-01' );
+		$this->assertEquals( '1900:01:01 00:00:00', $datetime->format( 'Y:m:d H:i:s' ) );
+
+		// Test with milliseconds
+		$datetime = wp_exif_datetime( '2024-03-15 14:30:00.123' );
+		$this->assertEquals( '2024:03:15 14:30:00', $datetime->format( 'Y:m:d H:i:s' ) );
+	}
+
+	/**
+	 * @ticket 56887
+	 *
+	 * Tests the functionality of parsing dates with different separators and ensures the output format is consistent.
+	 *
+	 * @return void
+	 */
+	public function test_different_separators() {
+
+		$datetime = wp_exif_datetime( '2024/03/15 14:30:00' );
+		$this->assertEquals( '2024:03:15 14:30:00', $datetime->format( 'Y:m:d H:i:s' ) );
+
+		$datetime = wp_exif_datetime( '2024/03/15 14:30:00' );
+		$this->assertEquals( '2024:03:15 14:30:00', $datetime->format( 'Y:m:d H:i:s' ) );
+	}
+}

tests/phpunit/tests/admin/includes/wpExifDate2TS.php

@@ -0,0 +1,71 @@
+<?php
+
+/**
+ * @group admin
+ * @group image
+ */
+class Tests_Admin_wpExifDate2ts extends WP_UnitTestCase {
+
+	/**
+	 * Test conversion of various date formats to EXIF format
+	 *
+	 * @dataProvider provideValidDates
+	 */
+	public function test_valid_dates( $input_date, $expected ) {
+		$result = wp_exif_datetime( $input_date );
+		$this->assertSame( $expected, $result->format( 'Y:m:d H:i:s' ) );
+	}
+
+	/**
+	 * Test that invalid inputs return false
+	 *
+	 * @dataProvider provideInvalidDates
+	 */
+	public function test_returns_false_for_invalid_input( $input ) {
+		$result = wp_exif_datetime( $input );
+		$this->assertFalse( $result );
+	}
+
+	/**
+	 * Data provider for valid dates
+	 */
+	public function provideValidDates() {
+		return array(
+			'mysql format'              => array(
+				'2024-03-15 14:30:00',
+				'2024:03:15 14:30:00',
+			),
+			'mysql format with seconds' => array(
+				'2024-03-15 14:30:45',
+				'2024:03:15 14:30:45',
+			),
+			'date only'                 => array(
+				'2024-03-15',
+				'2024:03:15 00:00:00',
+			),
+			'incomplete date'           => array(
+				'2024-03',
+				'2024:03:01 00:00:00',
+			),
+		);
+	}
+
+	/**
+	 * Data provider for invalid dates
+	 */
+	public function provideInvalidDates() {
+		return array(
+			'empty string'        => array( '' ),
+			'null'                => array( null ),
+			'invalid date string' => array( 'not a date' ),
+			'malformed date'      => array( '2024-13-45' ),
+			'boolean true'        => array( true ),
+			'boolean false'       => array( false ),
+			'array'               => array( array() ),
+			'object'              => array( new stdClass() ),
+			'invalid month'       => array( '2024-13-15' ),
+			'invalid day'         => array( '2024-03-32' ),
+			'invalid hour'        => array( '2024-03-15 25:00:00' ),
+		);
+	}
+}

tests/phpunit/tests/image/meta.php

@@ -217,6 +217,7 @@ public function data_stream() {
 					'title'             => 'IPTC Headline',
 					'orientation'       => '0',
 					'keywords'          => array(),
+					'created'           => '2004-07-22T17:14:35+00:00',
 				),
 			),
 			'Exif from a DMC-LX2 camera with keywords' => array(
@@ -234,6 +235,7 @@ public function data_stream() {
 					'title'             => 'Photoshop Document Ttitle',
 					'orientation'       => '1',
 					'keywords'          => array( 'beach', 'baywatch', 'LA', 'sunset' ),
+					'created'           => '2011-05-25T09:22:07+00:00',
 				),
 			),
 		);