src/third_party/mozjs-45/js/src/jit-test/tests/collections/Map-forEach.js

/* test Map.prototype.forEach */

load(libdir + 'asserts.js');
load(libdir + 'iteration.js');

// testing success conditions of Map.prototype.forEach

var testMap = new Map();

function callback(value, key, map) {
    testMap.set(key, value);
    assertEq(map.has(key), true);
    assertEq(map.get(key), value);
}

var initialMap = new Map([['a', 1], ['b', 2.3], [false, undefined]]);
initialMap.forEach(callback);

// test that both the Maps are equal and are in same order
var iterator = initialMap[Symbol.iterator]();
var count = 0;
for (var [k, v] of testMap) {
    assertEq(initialMap.has(k), true);
    assertEq(initialMap.get(k), testMap.get(k));
    assertIteratorNext(iterator, [k, testMap.get(k)]);
    count++;
}

//check both the Maps we have are equal in size
assertEq(initialMap.size, testMap.size);
assertEq(initialMap.size, count);

var x = { abc: 'test'};
function callback2(value, key, map) {
    assertEq(x, this);
}
initialMap = new Map([['a', 1]]);
initialMap.forEach(callback2, x);

// testing failure conditions of Map.prototype.forEach

var s = new Set([1, 2, 3]);
assertThrowsInstanceOf(function() {
    Map.prototype.forEach.call(s, callback);
}, TypeError, "Map.prototype.forEach should raise TypeError if not used on a Map");

var fn = 2;
assertThrowsInstanceOf(function() {
    initialMap.forEach(fn);
}, TypeError, "Map.prototype.forEach should raise TypeError if callback is not a function");

// testing that Map#forEach uses internal next() function and does not stop when
// StopIteration exception is thrown

var m = new Map([["one", 1]]);
Object.getPrototypeOf(m[Symbol.iterator]()).next = function () { throw "FAIL"; };
assertThrowsInstanceOf(function () {
  m.forEach(function () { throw StopIteration; });
}, StopIteration, "Map.prototype.forEach should use intrinsic next method.");