emailEditor = $this->diContainer->get(EmailEditor::class); $this->postRegisterCallback = function ($postTypes) { $postTypes[] = [ 'name' => 'custom_email_type', 'args' => [], 'meta' => [], ]; return $postTypes; }; add_filter('mailpoet_email_editor_post_types', $this->postRegisterCallback); $this->emailEditor->initialize(); } public function testItRegistersCustomPostTypeAddedViaHook() { $postTypes = get_post_types(); $this->assertArrayHasKey('custom_email_type', $postTypes); } public function _after() { parent::_after(); remove_filter('mailpoet_email_editor_post_types', $this->postRegisterCallback); } }