Add getter/setter methods

plugins/embed-optimizer/class-embed-optimizer-tag-visitor.php

@@ -227,7 +227,10 @@ private function reduce_layout_shifts( OD_Tag_Visitor_Context $context ): void {
 			if ( ! is_array( $resized_bounding_client_rect ) ) {
 				continue;
 			}
-			$group           = $element->url_metric->group;
+			$group = $element->get_url_metric_group();
+			if ( null === $group ) {
+				continue; // Technically could be null but in practice it never will be.
+			}
 			$group_min_width = $group->get_minimum_viewport_width();
 			if ( ! isset( $minimums[ $group_min_width ] ) ) {
 				$minimums[ $group_min_width ] = array(

plugins/optimization-detective/class-od-element.php

@@ -39,7 +39,7 @@ class OD_Element implements ArrayAccess, JsonSerializable {
 	 * @var OD_URL_Metric
 	 * @readonly
 	 */
-	public $url_metric;
+	protected $url_metric;
 
 	/**
 	 * Constructor.
@@ -56,6 +56,28 @@ public function __construct( array $data, OD_URL_Metric $url_metric ) {
 		$this->url_metric = $url_metric;
 	}
 
+	/**
+	 * Gets the URL metric that this element belongs to.
+	 *
+	 * @since n.e.x.t
+	 *
+	 * @return OD_URL_Metric URL Metric.
+	 */
+	public function get_url_metric(): OD_URL_Metric {
+		return $this->url_metric;
+	}
+
+	/**
+	 * Gets the group that this element's URL metric is a part of (which may not be any).
+	 *
+	 * @since n.e.x.t
+	 *
+	 * @return OD_URL_Metric_Group|null Group.
+	 */
+	public function get_url_metric_group(): ?OD_URL_Metric_Group {
+		return $this->url_metric->get_group();
+	}
+
 	/**
 	 * Gets property value for an arbitrary key.
 	 *

plugins/optimization-detective/class-od-url-metric-group.php

@@ -193,7 +193,7 @@ public function add_url_metric( OD_URL_Metric $url_metric ): void {
 			$this->collection->clear_cache();
 		}
 
-		$url_metric->group   = $this;
+		$url_metric->set_group( $this );
 		$this->url_metrics[] = $url_metric;
 
 		// If we have too many URL metrics now, remove the oldest ones up to the sample size.

plugins/optimization-detective/class-od-url-metric.php

@@ -67,9 +67,9 @@ class OD_URL_Metric implements JsonSerializable {
 	 * Group.
 	 *
 	 * @since n.e.x.t
-	 * @var OD_URL_Metric_Group
+	 * @var OD_URL_Metric_Group|null
 	 */
-	public $group;
+	protected $group = null;
 
 	/**
 	 * Constructor.
@@ -123,6 +123,33 @@ private function prepare_data( array $data ): array {
 		return rest_sanitize_value_from_schema( $data, $schema, self::class );
 	}
 
+	/**
+	 * Gets the group that this URL metric is a part of (which may not be any).
+	 *
+	 * @since n.e.x.t
+	 *
+	 * @return OD_URL_Metric_Group|null Group.
+	 */
+	public function get_group(): ?OD_URL_Metric_Group {
+		return $this->group;
+	}
+
+	/**
+	 * Sets the group that this URL metric is a part of.
+	 *
+	 * @since n.e.x.t
+	 *
+	 * @param OD_URL_Metric_Group $group Group.
+	 *
+	 * @throws InvalidArgumentException When the supplied group has minimum/maximum viewport widths which are out of bounds with the viewport width for this URL Metric.
+	 */
+	public function set_group( OD_URL_Metric_Group $group ): void {
+		if ( $this->get_viewport_width() < $group->get_minimum_viewport_width() || $this->get_viewport_width() > $group->get_maximum_viewport_width() ) {
+			throw new InvalidArgumentException( 'Group does not have the correct minimum or maximum viewport widths for this URL Metric.' );
+		}
+		$this->group = $group;
+	}
+
 	/**
 	 * Gets JSON schema for URL Metric.
 	 *

plugins/optimization-detective/tests/test-class-od-element.php

@@ -13,6 +13,8 @@ class Test_OD_Element extends WP_UnitTestCase {
 	 * Tests construction.
 	 *
 	 * @covers ::get
+	 * @covers ::get_url_metric
+	 * @covers ::get_url_metric_group
 	 * @covers ::is_lcp
 	 * @covers ::is_lcp_candidate
 	 * @covers ::get_xpath
@@ -67,6 +69,11 @@ static function ( array $schema ): array {
 
 		$element = $url_metric->get_elements()[0];
 		$this->assertInstanceOf( OD_Element::class, $element );
+		$this->assertSame( $url_metric, $element->get_url_metric() );
+		$this->assertNull( $element->get_url_metric_group() );
+		$collection = new OD_URL_Metric_Group_Collection( array( $url_metric ), array(), 1, DAY_IN_SECONDS );
+		$collection->add_url_metric( $url_metric );
+		$this->assertSame( iterator_to_array( $collection )[0], $element->get_url_metric_group() );
 
 		$this->assertSame( $element_data['xpath'], $element->get_xpath() );
 		$this->assertSame( $element_data['xpath'], $element['xpath'] );

plugins/optimization-detective/tests/test-class-od-url-metric.php

@@ -205,6 +205,8 @@ static function ( $value ) {
 	 * @covers ::jsonSerialize
 	 * @covers ::get
 	 * @covers ::get_json_schema
+	 * @covers ::set_group
+	 * @covers ::get_group
 	 *
 	 * @dataProvider data_provider_to_test_constructor
 	 *
@@ -217,6 +219,10 @@ public function test_constructor( array $data, string $error = '' ): void {
 			$this->expectExceptionMessage( $error );
 		}
 		$url_metric = new OD_URL_Metric( $data );
+		$this->assertNull( $url_metric->get_group() );
+		$group = new OD_URL_Metric_Group( array( $url_metric ), 0, PHP_INT_MAX, 1, DAY_IN_SECONDS );
+		$url_metric->set_group( $group );
+		$this->assertSame( $group, $url_metric->get_group() );
 
 		$this->assertSame( array_map( 'intval', $data['viewport'] ), $url_metric->get_viewport() );
 		$this->assertSame( array_map( 'intval', $data['viewport'] ), $url_metric->get( 'viewport' ) );

plugins/optimization-detective/tests/test-class-od-url-metrics-group-collection.php

@@ -742,8 +742,7 @@ public function test_get_all_element_max_intersection_ratios( array $url_metrics
 		$this->assertCount( count( $xpath_counts ), $all_elements );
 		foreach ( $all_elements as $xpath => $elements ) {
 			foreach ( $elements as $element ) {
-				$this->assertInstanceOf( OD_URL_Metric::class, $element->url_metric );
-				$this->assertInstanceOf( OD_URL_Metric_Group::class, $element->url_metric->group );
+				$this->assertSame( $element->get_url_metric()->get_group(), $element->get_url_metric_group() );
 				$this->assertInstanceOf( OD_Element::class, $element );
 				$this->assertSame( $xpath, $element['xpath'] );
 			}