Use command namespaces instead of conditional addition

checksum-command.php

@@ -9,10 +9,9 @@
 	require_once $autoload;
 }
 
-WP_CLI::add_hook( 'after_add_command:core', function () {
-	WP_CLI::add_command( 'core verify-checksums', 'Checksum_Core_Command' );
-} );
+WP_CLI::add_command( 'core', 'Core_Command_Namespace' );
+WP_CLI::add_command( 'core verify-checksums', 'Checksum_Core_Command' );
+
+WP_CLI::add_command( 'plugin', 'Plugin_Command_Namespace' );
+WP_CLI::add_command( 'plugin verify-checksums', 'Checksum_Plugin_Command' );
 
-WP_CLI::add_hook( 'after_add_command:plugin', function () {
-	WP_CLI::add_command( 'plugin verify-checksums', 'Checksum_Plugin_Command' );
-} );

src/Core_Command_Namespace.php

@@ -0,0 +1,10 @@
+<?php
+
+use WP_CLI\Dispatcher\CommandNamespace;
+
+/**
+ * Downloads, installs, updates, and manages a WordPress installation.
+ */
+final class Core_Command_Namespace extends CommandNamespace {
+
+}

src/Plugin_Command_Namespace.php

@@ -0,0 +1,10 @@
+<?php
+
+use WP_CLI\Dispatcher\CommandNamespace;
+
+/**
+ * Manages plugins, including installs, activations, and updates.
+ */
+final class Plugin_Command_Namespace extends CommandNamespace {
+
+}