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|
// Test iteration with a mapped arguments object.
function simple() {
function f() {
var sum = 0;
for (var v of arguments) {
sum += v;
}
return sum;
}
for (var i = 0; i < 100; ++i) {
assertEq(f(1, 2, 3), 6);
}
}
simple();
function spreadCall() {
function f() {
var sum = 0;
for (var v of arguments) {
sum += v;
}
return sum;
}
function g() {
return f(...arguments);
}
for (var i = 0; i < 100; ++i) {
assertEq(g(1, 2, 3), 6);
}
}
spreadCall();
function spreadArray() {
function f() {
var arr = [...arguments];
var sum = 0;
for (var v of arr) {
sum += v;
}
return sum;
}
for (var i = 0; i < 100; ++i) {
assertEq(f(1, 2, 3), 6);
}
}
spreadArray();
function reifyIterator() {
var reify = false;
function f() {
if (reify) {
// Redefining any property attributes will reify the iterator property.
Object.defineProperty(arguments, Symbol.iterator, {
writable: false
});
}
var sum = 0;
for (var v of arguments) {
sum += v;
}
return sum;
}
for (var i = 0; i <= 100; ++i) {
reify = i >= 50;
assertEq(f(1, 2, 3), 6);
}
}
reifyIterator();
function overwriteIterator() {
var callCount = 0;
function Iterator() {
callCount += 1;
return Array.prototype[Symbol.iterator].call(this);
}
var overwrite = false;
function f() {
if (overwrite) {
arguments[Symbol.iterator] = Iterator;
}
var sum = 0;
for (var v of arguments) {
sum += v;
}
return sum;
}
for (var i = 0; i <= 100; ++i) {
overwrite = i > 50;
assertEq(f(1, 2, 3), 6);
}
assertEq(callCount, 50);
}
overwriteIterator();
function deleteIterator() {
var remove = false;
function f() {
// Deleting Symbol.iterator won't change the shape of the arguments object.
// That's why we need to use a separate guard instruction to check if the
// iterator property was modified.
if (remove) {
delete arguments[Symbol.iterator];
}
var sum = 0;
for (var v of arguments) {
sum += v;
}
return sum;
}
var error;
try {
for (var i = 0; i <= 100; ++i) {
remove = i === 100;
assertEq(f(1, 2, 3), 6);
}
} catch (e) {
error = e;
}
assertEq(error instanceof TypeError, true);
}
deleteIterator();
function deleteIteratorInherit() {
var callCount = 0;
function Iterator() {
callCount += 1;
return Array.prototype[Symbol.iterator].call(this);
}
Object.prototype[Symbol.iterator] = Iterator;
var remove = false;
function f() {
// Deleting Symbol.iterator won't change the shape of the arguments object.
// That's why we need to use a separate guard instruction to check if the
// iterator property was modified.
if (remove) {
delete arguments[Symbol.iterator];
}
var sum = 0;
for (var v of arguments) {
sum += v;
}
return sum;
}
for (var i = 0; i <= 100; ++i) {
remove = i === 100;
assertEq(f(1, 2, 3), 6);
}
assertEq(callCount, 1);
delete Object.prototype[Symbol.iterator];
}
deleteIteratorInherit();
// Don't add tests below this point because |Object.prototype[Symbol.iterator]|
// was modified, which may lead to engine-wide deoptimisations.
|
