2 files changed, 140 insertions, 0 deletions
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
new file mode 100644
index 0000000..67d85f5
--- /dev/null
+++ b/tests/bootstrap.php
@@ -0,0 +1,31 @@
+<?php
+/**
+ * PHPUnit bootstrap file
+ *
+ * @package Draggable_Post_Order
+ */
+
+$_tests_dir = getenv( 'WP_TESTS_DIR' );
+
+if ( ! $_tests_dir ) {
+	$_tests_dir = rtrim( sys_get_temp_dir(), '/\\' ) . '/wordpress-tests-lib';
+}
+
+if ( ! file_exists( $_tests_dir . '/includes/functions.php' ) ) {
+	echo "Could not find $_tests_dir/includes/functions.php, have you run bin/install-wp-tests.sh ?" . PHP_EOL; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
+	exit( 1 );
+}
+
+// Give access to tests_add_filter() function.
+require_once $_tests_dir . '/includes/functions.php';
+
+/**
+ * Manually load the plugin being tested.
+ */
+function _manually_load_plugin() {
+	require dirname( dirname( __FILE__ ) ) . '/draggable-post-order.php';
+}
+tests_add_filter( 'muplugins_loaded', '_manually_load_plugin' );
+
+// Start up the WP testing environment.
+require $_tests_dir . '/includes/bootstrap.php';
diff --git a/tests/test-post-order.php b/tests/test-post-order.php
new file mode 100644
index 0000000..b5b26c7
--- /dev/null
+++ b/tests/test-post-order.php
@@ -0,0 +1,109 @@
+<?php
+/**
+ * Class TestPostOrder
+ *
+ * @package DraggablePostOrder
+ */
+
+/**
+ * Sample test case.
+ */
+class TestPostOrder extends WP_UnitTestCase {
+
+	/**
+	 * The post type for testing.
+	 *
+	 * @var WP_Post_Type
+	 */
+	public WP_Post_Type $test_post_type;
+
+	/**
+	 * Runs the routine before each test is executed.
+	 */
+	public function setUp(): void {
+		parent::setUp();
+
+		$this->test_post_type = register_post_type(
+			'test',
+			[
+				'supports'    => [ 'draggable-post-order' ],
+				'has_archive' => true,
+			]
+		);
+
+		// since tests are loaded after init, run init manually.
+		\Draggable_Post_Order\Draggable_Post_Order::init();
+	}
+
+	/**
+	 * Test query manipulation on meta_query
+	 */
+	public function test_query_manipulation_meta_query() {
+		$this->go_to( '/?post_type=test' );
+		$wp_query = $GLOBALS['wp_query'];
+
+		$meta_sub_query = [
+			'relation'                           => 'OR',
+			'draggable-post-order-clause'        => [
+				'key'  => 'draggable-post-order',
+				'type' => 'NUMERIC',
+			],
+			// get all posts without the meta as well.
+			'draggable-post-order-exists-clause' => [
+				'key'     => 'draggable-post-order',
+				'compare' => 'NOT EXISTS',
+			],
+		];
+		$this->assertEquals( [ $meta_sub_query ], $wp_query->get( 'meta_query' ) );
+	}
+
+	/**
+	 * Test query manipulation on orderby with ASC
+	 */
+	public function test_query_manipulation_orderby_asc() {
+		$this->go_to( '/?post_type=test' );
+		$wp_query = $GLOBALS['wp_query'];
+
+		$orderby = [
+			'draggable-post-order-clause'        => 'ASC',
+			'draggable-post-order-exists-clause' => 'ASC',
+		];
+		$this->assertEquals( $orderby, $wp_query->get( 'orderby' ) );
+	}
+
+	/**
+	 * Test query manipulation on orderby with DESC
+	 */
+	public function test_query_manipulation_orderby_desc() {
+		tests_add_filter(
+			'draggable_post_order_order',
+			function ( $order, $post_type, $query ) {
+				$this->assertEquals( 'ASC', $order );
+				$this->assertEquals( 'test', $post_type );
+				$this->assertTrue( $query->is_archive );
+
+				return 'DESC';
+			},
+			10,
+			3
+		);
+		$this->go_to( '/?post_type=test' );
+		$wp_query = $GLOBALS['wp_query'];
+
+		$orderby = [
+			'draggable-post-order-clause'        => 'DESC',
+			'draggable-post-order-exists-clause' => 'DESC',
+		];
+		$this->assertEquals( $orderby, $wp_query->get( 'orderby' ) );
+	}
+
+	/**
+	 * Test that query is not manipulated on unrelated pages
+	 */
+	public function test_query_manipulation_orderby_none() {
+		$this->go_to( '/' );
+		$wp_query = $GLOBALS['wp_query'];
+
+		$this->assertEmpty( $wp_query->get( 'orderby' ) );
+	}
+}