JSTests/es6/WeakMap_constructor_invokes_set.js

function test() {

var passed = false;
var _set = WeakMap.prototype.set;

WeakMap.prototype.set = function(k, v) {
  passed = true;
};

new WeakMap([ [{ }, 42] ]);
WeakMap.prototype.set = _set;

return passed;
      
}

if (!test())
    throw new Error("Test failed");