@@ -0,0 +1,322 @@
+<?php
+
+/**
+ * Admin Ajax functions to be tested.
+ */
+require_once ABSPATH . 'wp-admin/includes/ajax-actions.php';
+
+/**
+ * Testing wp_ajax_get_community_events() functionality.
+ *
+ * @package WordPress
+ * @subpackage UnitTests
+ *
+ * @group ajax
+ *
+ * @covers ::wp_ajax_get_community_events
+ */
+class Tests_Admin_Includes_AjaxActions_getCommunityEvents extends WP_Ajax_UnitTestCase {
+
+	/**
+	 * Administrator user ID.
+	 *
+	 * @var int
+	 */
+	protected static $admin_id;
+
+	/**
+	 * Original $_SERVER values.
+	 *
+	 * @var array
+	 */
+	private $server_backup;
+
+	/**
+	 * Requests made to the Events API.
+	 *
+	 * @var array[]
+	 */
+	private $requests = array();
+
+	/**
+	 * Mocked Events API response, or a WP_Error.
+	 *
+	 * @var array|WP_Error
+	 */
+	private $api_response;
+
+	/**
+	 * Setup test fixtures.
+	 *
+	 * @param WP_UnitTest_Factory $factory
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ): void {
+		self::$admin_id = $factory->user->create( array( 'role' => 'administrator' ) );
+	}
+
+	/**
+	 * Setup before each test method.
+	 */
+	public function set_up(): void {
+		parent::set_up();
+
+		// The test harness does not register this action.
+		add_action( 'wp_ajax_get-community-events', 'wp_ajax_get_community_events', 1 );
+		add_filter( 'pre_http_request', array( $this, 'mock_events_api' ), 10, 3 );
+
+		// WP_Community_Events sends the anonymized client IP, so make it predictable.
+		$this->server_backup = $_SERVER;
+		foreach ( array( 'HTTP_CLIENT_IP', 'HTTP_X_FORWARDED_FOR', 'HTTP_X_FORWARDED', 'HTTP_X_CLUSTER_CLIENT_IP', 'HTTP_FORWARDED_FOR', 'HTTP_FORWARDED' ) as $header ) {
+			unset( $_SERVER[ $header ] );
+		}
+		$_SERVER['REMOTE_ADDR'] = '203.0.113.5';
+
+		$this->api_response = $this->get_api_response_body();
+
+		wp_set_current_user( self::$admin_id );
+	}
+
+	/**
+	 * Tear down after each test method.
+	 */
+	public function tear_down(): void {
+		$_SERVER = $this->server_backup;
+		parent::tear_down();
+	}
+
+	/**
+	 * Mocks requests to the Events API.
+	 *
+	 * @param false|array|WP_Error $response Preemptive response.
+	 * @param array                $args     Request arguments.
+	 * @param string               $url      Request URL.
+	 * @return array|WP_Error Mocked response.
+	 */
+	public function mock_events_api( $response, $args, $url ) {
+		$this->requests[] = array(
+			'url'  => $url,
+			'args' => $args,
+		);
+
+		if ( is_wp_error( $this->api_response ) ) {
+			return $this->api_response;
+		}
+
+		return array(
+			'headers'  => array(),
+			'body'     => wp_json_encode( $this->api_response['body'] ),
+			'response' => array(
+				'code'    => $this->api_response['code'],
+				'message' => '',
+			),
+			'cookies'  => array(),
+			'filename' => null,
+		);
+	}
+
+	/**
+	 * Returns a successful Events API response with one expired and two upcoming events.
+	 *
+	 * @return array
+	 */
+	private function get_api_response_body(): array {
+		return array(
+			'code' => 200,
+			'body' => array(
+				'location' => array(
+					'description' => 'Paris',
+					'latitude'    => '48.857',
+					'longitude'   => '2.352',
+					'country'     => 'FR',
+					'ip'          => '198.51.100.99',
+				),
+				'events'   => array(
+					array(
+						'type'               => 'meetup',
+						'title'              => 'Past Meetup',
+						'end_unix_timestamp' => time() - DAY_IN_SECONDS,
+					),
+					array(
+						'type'               => 'meetup',
+						'title'              => 'Paris Meetup',
+						'end_unix_timestamp' => time() + DAY_IN_SECONDS,
+					),
+					array(
+						'type'               => 'wordcamp',
+						'title'              => 'WordCamp Paris',
+						'end_unix_timestamp' => time() + WEEK_IN_SECONDS,
+					),
+				),
+				'ttl'      => HOUR_IN_SECONDS,
+			),
+		);
+	}
+
+	/**
+	 * Returns the location the handler saves for the default API response.
+	 *
+	 * The API's IP is replaced with the anonymized IP sent in the request.
+	 *
+	 * @return array
+	 */
+	private function get_expected_location(): array {
+		$location       = $this->api_response['body']['location'];
+		$location['ip'] = '203.0.113.0';
+
+		return $location;
+	}
+
+	/**
+	 * @ticket 65252
+	 */
+	public function test_get_community_events_searches_location(): void {
+		// The client IP is unchanged, so only the search should replace the saved location.
+		update_user_meta(
+			self::$admin_id,
+			'community-events-location',
+			array(
+				'description' => 'Lyon',
+				'ip'          => '203.0.113.0',
+			)
+		);
+
+		$_POST = array(
+			'_ajax_nonce' => wp_create_nonce( 'community_events' ),
+			'location'    => 'Paris',
+			'timezone'    => 'Europe/Paris',
+		);
+
+		$response = json_decode( $this->get_ajax_response( 'get-community-events' ), true );
+
+		$this->assertTrue( $response['success'] );
+		$this->assertSame( $this->get_expected_location(), $response['data']['location'] );
+		$this->assertSame( array( 'Paris Meetup', 'WordCamp Paris' ), wp_list_pluck( $response['data']['events'], 'title' ), 'Expired events should be removed.' );
+		$this->assertSame( $this->get_expected_location(), get_user_meta( self::$admin_id, 'community-events-location', true ) );
+
+		$this->assertCount( 1, $this->requests );
+		$this->assertSame( 'api.wordpress.org', wp_parse_url( $this->requests[0]['url'], PHP_URL_HOST ) );
+		$this->assertSame( '/events/1.0/', wp_parse_url( $this->requests[0]['url'], PHP_URL_PATH ) );
+		$this->assertSame( 'Paris', $this->requests[0]['args']['body']['location'] );
+		$this->assertSame( 'Europe/Paris', $this->requests[0]['args']['body']['timezone'] );
+		$this->assertSame( '203.0.113.0', $this->requests[0]['args']['body']['ip'] );
+	}
+
+	/**
+	 * Without a location search, the saved location is only replaced when the client IP changes.
+	 *
+	 * @ticket 65252
+	 *
+	 * @dataProvider data_saved_location_without_search
+	 *
+	 * @param array|null $saved_location Location saved before the request, or null for none.
+	 * @param bool       $response_ip    Whether the API response includes an IP.
+	 * @param bool       $should_update  Whether the saved location should be replaced.
+	 */
+	public function test_get_community_events_updates_saved_location_when_ip_changes( ?array $saved_location, bool $response_ip, bool $should_update ): void {
+		if ( null !== $saved_location ) {
+			update_user_meta( self::$admin_id, 'community-events-location', $saved_location );
+		}
+
+		if ( ! $response_ip ) {
+			unset( $this->api_response['body']['location']['ip'] );
+		}
+
+		$_POST = array(
+			'_ajax_nonce' => wp_create_nonce( 'community_events' ),
+		);
+
+		$response = json_decode( $this->get_ajax_response( 'get-community-events' ), true );
+
+		$this->assertTrue( $response['success'] );
+		$this->assertCount( 1, $this->requests );
+
+		if ( $should_update ) {
+			$expected = $this->get_expected_location();
+		} else {
+			$expected = $saved_location ?? '';
+		}
+
+		$this->assertSame( $expected, get_user_meta( self::$admin_id, 'community-events-location', true ) );
+	}
+
+	/**
+	 * Data provider.
+	 *
+	 * @return array<string, array{ 0: array|null, 1: bool, 2: bool }>
+	 */
+	public static function data_saved_location_without_search(): array {
+		$saved_location = array(
+			'description' => 'Lyon',
+			'latitude'    => '45.764',
+			'longitude'   => '4.836',
+			'country'     => 'FR',
+		);
+
+		return array(
+			'no saved location'               => array( null, true, true ),
+			'saved location without an IP'    => array( $saved_location, true, true ),
+			'saved IP differs from client IP' => array( array_merge( $saved_location, array( 'ip' => '198.51.100.0' ) ), true, true ),
+			'saved IP matches client IP'      => array( array_merge( $saved_location, array( 'ip' => '203.0.113.0' ) ), true, false ),
+			'API response has no IP'          => array( null, false, false ),
+		);
+	}
+
+	/**
+	 * @ticket 65252
+	 */
+	public function test_get_community_events_returns_error_for_api_error_code(): void {
+		$this->api_response = array(
+			'code' => 500,
+			'body' => array(),
+		);
+
+		$_POST = array(
+			'_ajax_nonce' => wp_create_nonce( 'community_events' ),
+			'location'    => 'Paris',
+		);
+
+		$this->assertSame(
+			array(
+				'success' => false,
+				'data'    => array( 'error' => 'Invalid API response code (500).' ),
+			),
+			json_decode( $this->get_ajax_response( 'get-community-events' ), true )
+		);
+		$this->assertSame( '', get_user_meta( self::$admin_id, 'community-events-location', true ) );
+	}
+
+	/**
+	 * @ticket 65252
+	 */
+	public function test_get_community_events_returns_error_for_failed_request(): void {
+		$this->api_response = new WP_Error( 'http_request_failed', 'Mock connection failure.' );
+
+		$_POST = array(
+			'_ajax_nonce' => wp_create_nonce( 'community_events' ),
+			'location'    => 'Paris',
+		);
+
+		$this->assertSame(
+			array(
+				'success' => false,
+				'data'    => array( 'error' => 'Mock connection failure.' ),
+			),
+			json_decode( $this->get_ajax_response( 'get-community-events' ), true )
+		);
+		$this->assertSame( '', get_user_meta( self::$admin_id, 'community-events-location', true ) );
+	}
+
+	/**
+	 * @ticket 65252
+	 */
+	public function test_get_community_events_rejects_invalid_nonce(): void {
+		$_POST = array(
+			'_ajax_nonce' => 'invalid-nonce',
+			'location'    => 'Paris',
+		);
+
+		$this->assertSame( '-1', $this->get_ajax_response( 'get-community-events' ) );
+		$this->assertCount( 0, $this->requests, 'No API request should be made.' );
+		$this->assertSame( '', get_user_meta( self::$admin_id, 'community-events-location', true ) );
+	}
+}