Add basic unit tests

packages/block-library/src/navigation/index.php

@@ -484,6 +484,8 @@ function block_core_navigation_create_fallback() {
 	if ( ! $navigation_post ) {
 		$navigation_post = block_core_navigation_get_default_pages_fallback();
 	}
+
+	return $navigation_post;
 }
 
 

phpunit/navigation-block-fallback-test.php

@@ -0,0 +1,42 @@
+<?php
+/**
+ * Tests Fallback Behavior for Navigation block
+ *
+ * @package WordPress
+ */
+
+class Tests_Block_Navigation_Fallbacks extends WP_UnitTestCase {
+	public function set_up() {
+		parent::set_up();
+		switch_theme( 'emptytheme' );
+	}
+
+	public static function wpSetUpBeforeClass() {
+
+	}
+
+	public static function wpTearDownAfterClass() {
+
+	}
+
+	public function test_creates_fallback_with_page_list_by_default() {
+		$fallback = gutenberg_block_core_navigation_create_fallback();
+
+		$this->assertEquals( $fallback->post_type, 'wp_navigation' );
+		$this->assertEquals( $fallback->post_title, 'Navigation' );
+		$this->assertEquals( $fallback->post_content, '<!-- wp:page-list /-->' );
+		$this->assertEquals( $fallback->post_status, 'publish' );
+	}
+
+	public function test_skip_if_filter_returns_truthy() {
+		add_filter( 'block_core_navigation_skip_fallback', '__return_true' );
+
+		$actual = gutenberg_block_core_navigation_create_fallback();
+
+		$this->assertEquals( $actual, null );
+
+		remove_filter( 'block_core_navigation_skip_fallback', '__return_true' );
+	}
+}
+
+