Test and refactor Create_Block_Theme_Admin class

Starting with the export_child_theme method.

admin/class-create-theme.php

@@ -1,18 +1,18 @@
 <?php
 
-require_once( __DIR__ . '/resolver_additions.php' );
-require_once( __DIR__ . '/create-theme/theme-tags.php' );
-require_once( __DIR__ . '/create-theme/theme-zip.php' );
-require_once( __DIR__ . '/create-theme/theme-media.php' );
-require_once( __DIR__ . '/create-theme/theme-blocks.php' );
-require_once( __DIR__ . '/create-theme/theme-patterns.php' );
-require_once( __DIR__ . '/create-theme/theme-templates.php' );
-require_once( __DIR__ . '/create-theme/theme-styles.php' );
-require_once( __DIR__ . '/create-theme/theme-json.php' );
-require_once( __DIR__ . '/create-theme/theme-utils.php' );
-require_once( __DIR__ . '/create-theme/theme-readme.php' );
-require_once( __DIR__ . '/create-theme/theme-form.php' );
-require_once( __DIR__ . '/create-theme/form-messages.php' );
+require_once __DIR__ . '/resolver_additions.php';
+require_once __DIR__ . '/create-theme/theme-tags.php';
+require_once __DIR__ . '/create-theme/theme-zip.php';
+require_once __DIR__ . '/create-theme/theme-media.php';
+require_once __DIR__ . '/create-theme/theme-blocks.php';
+require_once __DIR__ . '/create-theme/theme-patterns.php';
+require_once __DIR__ . '/create-theme/theme-templates.php';
+require_once __DIR__ . '/create-theme/theme-styles.php';
+require_once __DIR__ . '/create-theme/theme-json.php';
+require_once __DIR__ . '/create-theme/theme-utils.php';
+require_once __DIR__ . '/create-theme/theme-readme.php';
+require_once __DIR__ . '/create-theme/theme-form.php';
+require_once __DIR__ . '/create-theme/form-messages.php';
 
 /**
  * The admin-specific functionality of the plugin.
@@ -22,7 +22,7 @@
  * @author     WordPress.org
  */
 class Create_Block_Theme_Admin {
-	private $theme;
+	public $theme;
 
 	/**
 	 * Initialize the class and set its properties.
@@ -42,7 +42,7 @@ function create_block_theme_enqueue() {
 			return;
 		}
 
-		$asset_file = include( plugin_dir_path( dirname( __FILE__ ) ) . 'build/plugin-sidebar.asset.php' );
+		$asset_file = include plugin_dir_path( dirname( __FILE__ ) ) . 'build/plugin-sidebar.asset.php';
 
 		wp_register_script(
 			'create-block-theme-slot-fill',
@@ -75,6 +75,19 @@ function save_variation( $export_type, $theme ) {
 		Theme_Json::add_theme_json_variation_to_local( 'variation', $theme );
 	}
 
+	public function download_file( $file, $filename ) {
+		// Set headers.
+		header( 'Content-Type: application/zip' );
+		header( 'Content-Disposition: attachment; filename=' . $filename );
+		header( 'Content-Length: ' . filesize( $file ) );
+
+		// Send file.
+		readfile( $file );
+
+		// Delete file.
+		unlink( $file );
+	}
+
 	/**
 	 * Export activated child theme
 	 */
@@ -91,12 +104,10 @@ function export_child_theme( $theme ) {
 
 		$zip->close();
 
-		header( 'Content-Type: application/zip' );
-		header( 'Content-Disposition: attachment; filename=' . $theme['slug'] . '.zip' );
-		header( 'Content-Length: ' . filesize( $filename ) );
-		flush();
-		echo readfile( $filename );
-		die();
+		// Download the ZIP file.
+		$this->download_file( $filename, $theme['slug'] . '.zip' );
+
+		return $filename;
 	}
 
 	/**
@@ -233,7 +244,6 @@ function clone_theme( $theme, $screenshot ) {
 	 * Create a child theme of the activated theme
 	 */
 	function create_child_theme( $theme, $screenshot ) {
-
 		$parent_theme_slug = Theme_Utils::get_theme_slug( $this->theme->get( 'Name' ) );
 		$child_theme_slug  = Theme_Utils::get_theme_slug( $theme['name'] );
 
@@ -379,11 +389,9 @@ function create_blank_theme( $theme, $screenshot ) {
 				file_put_contents( $theme_json_path, $theme_json_string );
 			}
 		}
-
 	}
 
 	function blockbase_save_theme() {
-
 		if ( ! empty( $_GET['page'] ) && 'create-block-theme' === $_GET['page'] && ! empty( $_POST['theme'] ) ) {
 
 			// Check user capabilities.
@@ -412,7 +420,6 @@ function blockbase_save_theme() {
 
 				add_action( 'admin_notices', array( 'Form_Messages', 'admin_notice_save_success' ) );
 			} elseif ( 'variation' === $_POST['theme']['type'] ) {
-
 				if ( '' === $_POST['theme']['variation'] ) {
 					return add_action( 'admin_notices', array( 'Form_Messages', 'admin_notice_error_variation_name' ) );
 				}

tests/test-theme-create-theme.php

@@ -0,0 +1,55 @@
+<?php
+/**
+ * Class WP_Create_Block_Theme_Admin
+ *
+ * @package Create_Block_Theme
+ */
+class Create_Block_Theme_AdminTest extends WP_UnitTestCase {
+	public function setUp(): void {
+		parent::setUp();
+		$this->class_instance = new Create_Block_Theme_Admin();
+	}
+
+	/**
+	 * Test if the class exists.
+	 */
+	public function test_theme_instance() {
+		$class_name = get_class( $this->class_instance->theme );
+		$expected   = 'WP_Theme';
+
+		$this->assertEquals( $expected, $class_name );
+	}
+
+	/**
+	 * Test if the export_child_theme correctly creates a child theme.
+	 */
+	public function test_export_child_theme() {
+		$create_block_theme_admin = $this->getMockBuilder( 'Create_Block_Theme_Admin' )
+		->setMethods( array( 'download_file' ) )
+			->getMock();
+
+		// Configure the stub.
+		$create_block_theme_admin->method( 'download_file' )
+		->willReturn( true );
+
+		$theme_name                = 'twentytwentythree';
+		$expected_child_theme_name = 'twentytwentythree-child';
+
+		switch_theme( $theme_name );
+		$current_theme = wp_get_theme();
+
+		$filename = $create_block_theme_admin->export_child_theme( $current_theme );
+
+		// check that the zip file exists in the temp dir.
+		$this->assertFileExists( $filename );
+
+		// check that it contains a valid WordPress theme.
+		$zip = new ZipArchive();
+		$zip->open( $filename );
+		$zip->extractTo( get_theme_root() . '/' . $expected_child_theme_name );
+		$zip->close();
+
+		$child_theme = wp_get_theme( $expected_child_theme_name );
+		$this->assertTrue( $child_theme->exists() );
+	}
+}