namespace Updraft {
	/* istanbul ignore next */
	function makePrintable(x: any): string {
		if (Array.isArray(x) || (x && typeof x === "object")) {
			return JSON.stringify(x);
		}
		else {
			return x;
		}
	}
	
	/**
	* Use verify() to assert state which your program assumes to be true.
	*
	* Provide sprintf-style format (only %s is supported) and arguments
	* to provide information about what broke and what you were
	* expecting.
	*/
	export function verify(condition: any, format: string, ...args: any[]) {
		/* istanbul ignore next */
		if (!condition) {
			let argIndex = 0;
			let error = new Error(
				format.replace(/%s/g, function() { return makePrintable(args[argIndex++]); })
			);
	
			(<any>error).framesToPop = 1; // we don't care about verify's own frame
			throw error;
		}
	}
}