Merge pull request #22 from Nomafin/patch-no-superadmins

Fix a bug where adding superadmins would crash if none existed before

features/super-admin.feature

@@ -219,3 +219,16 @@ Feature: Manage super admins associated with a multisite instance
       """
       admin
       """
+
+  Scenario: Handle a site with an empty site_admins option without errors
+    Given a WP multisite installation
+
+    When I run `wp site option set site_admins ''`
+    Then STDOUT should be:
+      """
+      Success: Updated 'site_admins' site option.
+      """
+    And STDERR should be empty
+
+    When I run `wp super-admin list`
+    Then STDERR should be empty

src/Super_Admin_Command.php

@@ -194,6 +194,6 @@ public function remove( $args, $_ ) {
 
 	private static function get_admins() {
 		// We don't use get_super_admins() because we don't want to mess with the global
-		return get_site_option( 'site_admins', array('admin') );
+		return (array) get_site_option( 'site_admins', array('admin') );
 	}
 }