Source code
Revision control
Copy as Markdown
Other Tools
// This test case check some code frequently used in the wild, with some object
// (proxy) for which the optimization we have deployed do not work, as the
// assumption the Object.keys(...) can be elided without having noticeable
// side-effects.
// Similar functions are part of popular framework such as React and Angular.
function shallowEqual(o1, o2) {
var k1 = Object.keys(o1);
var k2 = Object.keys(o2);
if (k1.length != k2.length) {
return false;
}
for (var k = 0; k < k1.length; k++) {
if (!Object.hasOwnProperty.call(o2, k1[k]) || !Object.is(o1[k1[k]], o2[k1[k]])) {
return false;
}
}
return true;
}
let sideEffectCounter = 0;
const payload = {x: 5, a: 1, b: 2, c: 3, d: 4};
const handler = {
ownKeys(target) {
// side-effect that should not be removed.
sideEffectCounter++;
// answer returned.
return Reflect.ownKeys(target);
},
};
const proxy = new Proxy(payload, handler);
let objs = [
{x:0, a: 1, b: 2},
{x:1, b: 1, c: 2},
{x:2, c: 1, d: 2},
{x:3, a: 1, b: 2, c: 3},
{x:4, b: 1, c: 2, d: 3},
proxy
];
with({}) {}
let iterMax = 1000;
for (let i = 0; i < iterMax; i++) {
for (let o1 of objs) {
for (let o2 of objs) {
assertEq(shallowEqual(o1, o2), Object.is(o1, o2));
}
}
}
let expectedSideEffects = 2 * objs.length * iterMax;
assertEq(sideEffectCounter, expectedSideEffects);