Add tests for permalink filters

tests/test-permalink-filters.php

+<?php
+/**
+ * Class PermalinkFilters
+ *
+ * @package External_Permalinks_Redux
+ */
+
+/**
+ * Test permalink filters
+ */
+class PermalinkFilters extends WP_UnitTestCase {
+	/**
+	 * Redirect destination.
+	 */
+	const DESTINATION = 'https://w.org/';
+
+	/**
+	 * Test post ID.
+	 *
+	 * @var int
+	 */
+	protected $post_id;
+
+	/**
+	 * Test page ID.
+	 *
+	 * @var int
+	 */
+	protected $page_id;
+
+	/**
+	 * Create some objects with redirects.
+	 */
+	public function setUp() {
+		parent::setUp();
+
+		$plugin = external_permalinks_redux::get_instance();
+
+		$this->post_id = $this->factory->post->create(
+			[
+				'post_type' => 'post',
+			]
+		);
+
+		update_post_meta( $this->post_id, $plugin->meta_key_target, static::DESTINATION );
+
+		$this->page_id = $this->factory->post->create(
+			[
+				'post_type' => 'page',
+			]
+		);
+
+		update_post_meta( $this->page_id, $plugin->meta_key_target, static::DESTINATION );
+	}
+
+	/**
+	 * Test post permalink filter.
+	 */
+	public function test_post() {
+		$this->assertEquals( static::DESTINATION, get_permalink( $this->post_id ) );
+	}
+
+	/**
+	 * Test page link filter.
+	 */
+	public function test_page() {
+		$this->assertEquals( static::DESTINATION, get_page_link( $this->page_id ) );
+	}
+}

tests/test-sample.php

-<?php
-/**
- * Class SampleTest
- *
- * @package External_Permalinks_Redux
- */
-
-/**
- * Sample test case.
- */
-class SampleTest extends WP_UnitTestCase {
-
-	/**
-	 * A single example test.
-	 */
-	public function test_sample() {
-		// Replace this with some actual testing code.
-		$this->assertTrue( true );
-	}
-}