Abstract redirect lookup so it can be tested

external-permalinks-redux.php

@@ -230,21 +230,43 @@ class external_permalinks_redux {
 			return;
 		}
 
-		$link = get_post_meta( $post->ID, $this->meta_key_target, true );
+		$redirect = $this->get_redirect_data( $post->ID );
 
-		if ( ! empty( $link ) ) {
-			$type = (int) get_post_meta( $post->ID, $this->meta_key_type, true );
-			$type = apply_filters( 'epr_status_code', $type, $link, $post );
+		if ( false === $redirect ) {
+			return;
+		}
 
-			if ( ! $type ) {
-				$type = 302;
-			}
+		// Unreasonable to validate redirect destination.
+		// phpcs:ignore WordPress.Security.SafeRedirect.wp_redirect_wp_redirect
+		wp_redirect( $redirect['link'], $redirect['type'] );
+		exit;
+	}
 
-			// Unreasonable to validate redirect destination.
-			// phpcs:ignore WordPress.Security.SafeRedirect.wp_redirect_wp_redirect
-			wp_redirect( $link, $type );
-			exit;
+	/**
+	 * Retrieve redirect data for a given post ID.
+	 *
+	 * @param int $post_id Post ID.
+	 * @return array|bool
+	 */
+	public function get_redirect_data( $post_id ) {
+		if ( ! is_numeric( $post_id ) ) {
+			return false;
 		}
+
+		$link = get_post_meta( $post_id, $this->meta_key_target, true );
+
+		if ( empty( $link ) ) {
+			return false;
+		}
+
+		$type = (int) get_post_meta( $post_id, $this->meta_key_type, true );
+		$type = apply_filters( 'epr_status_code', $type, $link, get_post( $post_id ) );
+
+		if ( ! $type ) {
+			$type = 302;
+		}
+
+		return compact( 'link', 'type' );
 	}
 }
 

tests/test-redirect-callbacks.php

+<?php
+/**
+ * Class RedirectCallbacks
+ *
+ * @package External_Permalinks_Redux
+ */
+
+/**
+ * Test redirect callbacks
+ */
+class RedirectCallbacks extends WP_UnitTestCase {
+	/**
+	 * Redirect destination.
+	 */
+	const DESTINATION = 'https://w.org/';
+
+	/**
+	 * Plugin instance.
+	 *
+	 * @var external_permalinks_redux
+	 */
+	protected $plugin;
+
+	/**
+	 * Create some objects with redirects.
+	 */
+	public function setUp() {
+		parent::setUp();
+
+		$this->plugin = external_permalinks_redux::get_instance();
+	}
+
+	/**
+	 * Helper to retrieve a clean post.
+	 *
+	 * @return int
+	 */
+	protected function get_new_post() {
+		return $this->factory->post->create(
+			[
+				'post_type' => 'post',
+			]
+		);
+	}
+
+	/**
+	 * Test post with default redirect code.
+	 */
+	public function test_post_redirect_default_status() {
+		$post_id = $this->get_new_post();
+		update_post_meta( $post_id, $this->plugin->meta_key_target, static::DESTINATION );
+
+		$redirect = $this->plugin->get_redirect_data( $post_id );
+
+		$this->assertEquals( static::DESTINATION, $redirect['link'] );
+		$this->assertEquals( 302, $redirect['type'] );
+	}
+
+	/**
+	 * test post with custom redirect code.
+	 */
+	public function test_post_redirect_custom_status() {
+		$post_id = $this->get_new_post();
+		update_post_meta( $post_id, $this->plugin->meta_key_target, static::DESTINATION );
+		update_post_meta( $post_id, $this->plugin->meta_key_type, 307 );
+
+		$redirect = $this->plugin->get_redirect_data( $post_id );
+
+		$this->assertEquals( static::DESTINATION, $redirect['link'] );
+		$this->assertEquals( 307, $redirect['type'] );
+	}
+
+	/**
+	 * Test post with redirect type but no destination.
+	 */
+	public function test_post_redirect_missing_destination() {
+		$post_id = $this->get_new_post();
+		update_post_meta( $post_id, $this->plugin->meta_key_type, 307 );
+
+		$redirect = $this->plugin->get_redirect_data( $post_id );
+
+		$this->assertFalse( $redirect );
+	}
+
+	/**
+	 * Test post without redirect.
+	 */
+	public function test_post_no_redirect() {
+		$post_id = $this->get_new_post();
+		$redirect = $this->plugin->get_redirect_data( $post_id );
+
+		$this->assertFalse( $redirect );
+	}
+}