Preserve filters when searching on events page

phpunit-bootstrap.php

@@ -55,6 +55,7 @@
 require_once WP_PLUGIN_DIR . '/wordcamp-payments-network/tests/bootstrap.php';
 require_once SUT_WPMU_PLUGIN_DIR . '/tests/bootstrap.php';
 require_once WP_PLUGIN_DIR . '/wordcamp-coming-soon-page/tests/bootstrap.php';
+require_once SUT_WP_CONTENT_DIR . '/themes/wporg-events-2023/tests/bootstrap.php';
 
 /*
  * This has to be the last plugin bootstrapper, because it includes the Core test bootstrapper, which would

phpunit.xml.dist

@@ -67,6 +67,12 @@
 				./public_html/wp-content/plugins/wordcamp-coming-soon-page/tests/
 			</directory>
 		</testsuite>
+
+		<testsuite name="Events Theme">
+			<directory prefix="test-" suffix=".php">
+				./public_html/wp-content/themes/wporg-events-2023/tests/
+			</directory>
+		</testsuite>
 	</testsuites>
 
 	<coverage cacheDirectory=".phpunit/coverage-cache">

public_html/wp-content/themes/wporg-events-2023/inc/events-query.php

@@ -24,6 +24,7 @@
 add_action( 'wporg_query_filter_in_form', __NAMESPACE__ . '\inject_other_filters' );
 add_filter( 'document_title_parts', __NAMESPACE__ . '\add_filters_to_page_title' );
 add_filter( 'wporg_query_total_label', __NAMESPACE__ . '\update_query_total_label', 10, 3 );
+add_filter( 'render_block_core/search', __NAMESPACE__ . '\inject_filters_into_search_form' );
 add_filter( 'wporg_query_filter_options_format_type', __NAMESPACE__ . '\get_format_type_options' );
 add_filter( 'wporg_query_filter_options_event_type', __NAMESPACE__ . '\get_event_type_options' );
 add_filter( 'wporg_query_filter_options_month', __NAMESPACE__ . '\get_month_options' );
@@ -329,6 +330,52 @@ function inject_other_filters( string $key ): void {
 	}
 }
 
+/**
+ * Inject active filter values as hidden inputs into the search form.
+ *
+ * The core/search block submits only `?s=term` to the home URL, losing any
+ * active filters and redirecting away from the events page. This modifies
+ * the form to submit to the events page and includes active filters as
+ * hidden inputs.
+ *
+ * @param string $block_content The block HTML.
+ *
+ * @return string Modified block HTML with hidden filter inputs.
+ */
+function inject_filters_into_search_form( string $block_content ): string {
+	$query_vars = array( 'event_type', 'format_type', 'month', 'country' );
+	$hidden_inputs = '';
+
+	foreach ( $query_vars as $query_var ) {
+		$values = (array) get_query_var( $query_var, array() );
+
+		foreach ( $values as $value ) {
+			if ( '' !== $value ) {
+				$hidden_inputs .= sprintf(
+					'<input type="hidden" name="%s[]" value="%s" />',
+					esc_attr( $query_var ),
+					esc_attr( $value )
+				);
+			}
+		}
+	}
+
+	// Update the form action to stay on the events page rather than going to
+	// the default WordPress search results page.
+	$action_url    = build_form_action_url();
+	$block_content = preg_replace(
+		'/action="[^"]*"/',
+		'action="' . esc_url( $action_url ) . '"',
+		$block_content
+	);
+
+	if ( $hidden_inputs ) {
+		$block_content = str_replace( '</form>', $hidden_inputs . '</form>', $block_content );
+	}
+
+	return $block_content;
+}
+
 /**
  * Append facets to the page title.
  *

public_html/wp-content/themes/wporg-events-2023/tests/bootstrap.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace WordPressdotorg\Events_2023\Tests;
+
+if ( 'cli' !== php_sapi_name() ) {
+	return;
+}
+
+/**
+ * Load the theme files needed for tests.
+ */
+function manually_load_theme() {
+	require_once dirname( __DIR__ ) . '/inc/events-query.php';
+}
+
+tests_add_filter( 'after_setup_theme', __NAMESPACE__ . '\manually_load_theme' );

public_html/wp-content/themes/wporg-events-2023/tests/test-events-query.php

@@ -0,0 +1,153 @@
+<?php
+
+namespace WordPressdotorg\Events_2023\Tests;
+
+use WP_UnitTestCase;
+
+defined( 'WPINC' ) || die();
+
+/**
+ * @group wporg-events-2023
+ *
+ * @coversDefaultClass \WordPressdotorg\Events_2023
+ */
+class Test_Events_Query extends WP_UnitTestCase {
+
+	/**
+	 * Sample search form HTML to use in tests.
+	 *
+	 * @var string
+	 */
+	private $sample_form = '<form role="search" method="get" action="http://example.org/" class="wp-block-search__button-outside"><label class="wp-block-search__label" for="wp-block-search__input-1">Search</label><div class="wp-block-search__inside-wrapper"><input class="wp-block-search__input" id="wp-block-search__input-1" placeholder="" value="" name="s" /><button aria-label="Search" class="wp-block-search__button" type="submit">Search</button></div></form>';
+
+	/**
+	 * Clean up query vars after each test.
+	 */
+	public function tear_down(): void {
+		global $wp_query;
+
+		set_query_var( 'event_type', '' );
+		set_query_var( 'format_type', '' );
+		set_query_var( 'month', '' );
+		set_query_var( 'country', '' );
+
+		parent::tear_down();
+	}
+
+	/**
+	 * Test that hidden inputs are injected when active filters exist.
+	 *
+	 * @covers ::inject_filters_into_search_form
+	 */
+	public function test_injects_hidden_inputs_for_active_filters(): void {
+		set_query_var( 'event_type', array( 'meetup' ) );
+		set_query_var( 'country', array( 'US' ) );
+
+		$result = \WordPressdotorg\Events_2023\inject_filters_into_search_form( $this->sample_form );
+
+		$this->assertStringContainsString(
+			'<input type="hidden" name="event_type[]" value="meetup" />',
+			$result
+		);
+		$this->assertStringContainsString(
+			'<input type="hidden" name="country[]" value="US" />',
+			$result
+		);
+	}
+
+	/**
+	 * Test that multiple values for a single filter produce multiple hidden inputs.
+	 *
+	 * @covers ::inject_filters_into_search_form
+	 */
+	public function test_injects_multiple_values_for_same_filter(): void {
+		set_query_var( 'event_type', array( 'meetup', 'wordcamp' ) );
+
+		$result = \WordPressdotorg\Events_2023\inject_filters_into_search_form( $this->sample_form );
+
+		$this->assertStringContainsString(
+			'<input type="hidden" name="event_type[]" value="meetup" />',
+			$result
+		);
+		$this->assertStringContainsString(
+			'<input type="hidden" name="event_type[]" value="wordcamp" />',
+			$result
+		);
+	}
+
+	/**
+	 * Test that hidden inputs are placed before the closing form tag.
+	 *
+	 * @covers ::inject_filters_into_search_form
+	 */
+	public function test_hidden_inputs_placed_before_closing_form_tag(): void {
+		set_query_var( 'event_type', array( 'meetup' ) );
+
+		$result = \WordPressdotorg\Events_2023\inject_filters_into_search_form( $this->sample_form );
+
+		$this->assertStringContainsString(
+			'value="meetup" /></form>',
+			$result
+		);
+	}
+
+	/**
+	 * Test that form HTML has no hidden inputs when no filters are active.
+	 *
+	 * @covers ::inject_filters_into_search_form
+	 */
+	public function test_no_hidden_inputs_when_no_filters_active(): void {
+		$result = \WordPressdotorg\Events_2023\inject_filters_into_search_form( $this->sample_form );
+
+		$this->assertStringNotContainsString( '<input type="hidden"', $result );
+	}
+
+	/**
+	 * Test that the form action URL is updated.
+	 *
+	 * @covers ::inject_filters_into_search_form
+	 */
+	public function test_form_action_url_is_updated(): void {
+		$post_id = self::factory()->post->create( array(
+			'post_title'  => 'Upcoming Events',
+			'post_status' => 'publish',
+		) );
+
+		$this->go_to( get_permalink( $post_id ) );
+
+		$result = \WordPressdotorg\Events_2023\inject_filters_into_search_form( $this->sample_form );
+
+		// The action should no longer be the original example.org URL.
+		$this->assertStringNotContainsString( 'action="http://example.org/"', $result );
+		// It should contain an action attribute with a URL pointing to the post.
+		$this->assertMatchesRegularExpression( '/action="https?:\/\/[^"]+?"/', $result );
+	}
+
+	/**
+	 * Test that empty filter values are not injected.
+	 *
+	 * @covers ::inject_filters_into_search_form
+	 */
+	public function test_empty_filter_values_are_not_injected(): void {
+		set_query_var( 'event_type', array( '' ) );
+		set_query_var( 'month', array( '' ) );
+
+		$result = \WordPressdotorg\Events_2023\inject_filters_into_search_form( $this->sample_form );
+
+		$this->assertStringNotContainsString( '<input type="hidden"', $result );
+	}
+
+	/**
+	 * Test that filter values are properly escaped in HTML output.
+	 *
+	 * @covers ::inject_filters_into_search_form
+	 */
+	public function test_filter_values_are_escaped(): void {
+		set_query_var( 'event_type', array( '<script>alert(1)</script>' ) );
+
+		$result = \WordPressdotorg\Events_2023\inject_filters_into_search_form( $this->sample_form );
+
+		$this->assertStringNotContainsString( '<script>', $result );
+		$this->assertStringContainsString( '&lt;script&gt;', $result );
+	}
+}