export function isValidMenuItems(menu: IUserFriendlyMenuItem[], collector: IExtensionMessageCollector): boolean {
		if (!Array.isArray(menu)) {
			collector.error(localize('requirearry', "menu items must be an arry"));
			return false;
		}

		for (let item of menu) {
			if (typeof item.command !== 'string') {
				collector.error(localize('requirestring', "property `{0}` is mandatory and must be of type `string`", 'command'));
				return false;
			}
			if (item.alt && typeof item.alt !== 'string') {
				collector.error(localize('optstring', "property `{0}` can be omitted or must be of type `string`", 'alt'));
				return false;
			}
			if (item.when && typeof item.when !== 'string') {
				collector.error(localize('optstring', "property `{0}` can be omitted or must be of type `string`", 'when'));
				return false;
			}
			if (item.group && typeof item.group !== 'string') {
				collector.error(localize('optstring', "property `{0}` can be omitted or must be of type `string`", 'group'));
				return false;
			}
		}

		return true;
	}

	function isValidIcon(icon: IUserFriendlyIcon, collector: IExtensionMessageCollector): boolean {
		if (typeof icon === 'undefined') {
			return true;
		}
		if (typeof icon === 'string') {
			return true;
		} else if (typeof icon.dark === 'string' && typeof icon.light === 'string') {
			return true;
		}
		collector.error(localize('opticon', "property `icon` can be omitted or must be either a string or a literal like `{dark, light}`"));
		return false;
	}

	export function isValidCommand(command: IUserFriendlyCommand, collector: IExtensionMessageCollector): boolean {
		if (!command) {
			collector.error(localize('nonempty', "expected non-empty value."));
			return false;
		}
		if (typeof command.command !== 'string') {
			collector.error(localize('requirestring', "property `{0}` is mandatory and must be of type `string`", 'command'));
			return false;
		}
		if (typeof command.title !== 'string') {
			collector.error(localize('requirestring', "property `{0}` is mandatory and must be of type `string`", 'title'));
			return false;
		}
		if (command.category && typeof command.category !== 'string') {
			collector.error(localize('optstring', "property `{0}` can be omitted or must be of type `string`", 'category'));
			return false;
		}
		if (!isValidIcon(command.icon, collector)) {
			return false;
		}
		return true;
	}