Allow static checks to be run against an arbitrary path

includes/Checker/Abstract_Check_Runner.php

@@ -525,7 +525,9 @@ final protected function get_categories() {
 	 * @return Check_Context The check context for the plugin file.
 	 */
 	private function get_check_context() {
-		return new Check_Context( WP_PLUGIN_DIR . '/' . $this->get_plugin_basename() );
+		$plugin_basename = $this->get_plugin_basename();
+		$plugin_path     = is_dir( $plugin_basename ) ? $plugin_basename : WP_PLUGIN_DIR . '/' . $plugin_basename;
+		return new Check_Context( $plugin_path );
 	}
 
 	/**

includes/Checker/Checks/Plugin_Readme_Check.php

@@ -225,7 +225,7 @@ private function check_default_text( Check_Result $result, string $readme_file,
 	private function check_license( Check_Result $result, string $readme_file, Parser $parser ) {
 		$license          = $parser->license;
 		$matches_license  = array();
-		$plugin_main_file = WP_PLUGIN_DIR . '/' . $result->plugin()->basename();
+		$plugin_main_file = $result->plugin()->main_file();
 
 		// Filter the readme files.
 		if ( empty( $license ) ) {

includes/Plugin_Context.php

@@ -69,6 +69,26 @@
 		return plugin_basename( $this->main_file );
 	}
 
+	/**
+	 * Returns the plugin main file.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @return string Plugin main file.
+	 */
+	public function main_file() {
+		if ( false === strpos( $this->main_file, '.php' ) ) {
+			$files = glob( $this->main_file . '/*.php' );
+			foreach ( $files as $file ) {
+				$plugin_data = get_plugin_data( $file );
+				if ( ! empty( $plugin_data['Name'] ) ) {
+					return $file;
+				}
+			}
+		}
+		return $this->main_file;
+	}
+
 	/**
 	 * Returns the absolute path for a relative path to the plugin directory.
 	 *
@@ -78,7 +98,11 @@
 	 * @return string Absolute path.
 	 */
 	public function path( $relative_path = '/' ) {
-		return plugin_dir_path( $this->main_file ) . ltrim( $relative_path, '/' );
+		if ( is_dir( $this->main_file ) ) {
+			return trailingslashit( $this->main_file ) . ltrim( $relative_path, '/' );
+		} else {
+			return plugin_dir_path( $this->main_file ) . ltrim( $relative_path, '/' );
+		}
 	}
 
 	/**

includes/Utilities/Plugin_Request_Utility.php

@@ -40,12 +40,16 @@
 	 *
 	 * @since 1.0.0
 	 *
-	 * @param string $plugin_slug The plugin slug or basename.
+	 * @param string $plugin_slug The plugin slug, basename or arbitrary path.
 	 * @return string The plugin basename.
 	 *
 	 * @throws Exception Thrown if an invalid basename or plugin slug is provided.
 	 */
 	public static function get_plugin_basename_from_input( $plugin_slug ) {
+		if ( is_dir( $plugin_slug ) ) {
+			return $plugin_slug;
+		}
+
 		require_once ABSPATH . 'wp-admin/includes/plugin.php';
 
 		if ( empty( $plugin_slug ) ) {