Function assert

lib/web/polyfill.js:342–344

(condition, msg1, msg2)

// Assertion & errors
var REDUCE_ERROR = 'Reduce of empty object with no initial value';
function assert(condition, msg1, msg2){
  if(!condition)throw TypeError(msg2 ? msg1 + msg2 : msg1);
}
function assertDefined(it){
  if(it == undefined)throw TypeError('Function called on null or undefined');
  return it;