firefox-main/dom/base/test/test_htmlcollection_spread_duplicate_keys.html (file symbol)

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Test Info: Warnings

<!DOCTYPE HTML>
<html>
<!--
-->
<head>
<meta charset="UTF-8">
<title>Test for Bug 2067720</title>
<script src="/tests/SimpleTest/SimpleTest.js"></script>
<link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
</head>
<body>
<div id="content"></div>
<script>
// An HTMLCollection reports a named item and an expando with the same name as
// two separate own keys. Copying such a collection into a fresh object must
// still produce a single property for that name.
function makeCollection(name) {
const host = document.createElement("div");
document.getElementById("content").append(host);
const collection = host.getElementsByTagName("span");
for (let i = 0; i < 8; i++) {
Object.defineProperty(collection, "x" + i, {
value: 1000 + i,
writable: true,
enumerable: true,
configurable: true,
});
}
Object.defineProperty(collection, name, {
get() {
return "expando";
},
enumerable: true,
configurable: true,
});
const child = document.createElement("span");
child.id = name;
host.append(child);
return { host, collection };
}
function checkCopy(copy, name, label) {
const keys = Object.keys(copy);
is(
keys.length,
new Set(keys).size,
`${label}: copied keys are unique: ${keys}`
);
is(keys.filter(k => k == name).length, 1, `${label}: ${name} is copied once`);
for (let i = 0; i < 5; i++) {
delete copy["x" + i];
}
delete copy[name];
is(copy[name], undefined, `${label}: ${name} was deleted`);
for (let i = 5; i < 8; i++) {
is(copy["x" + i], 1000 + i, `${label}: x${i} survives the deletes`);
}
copy[name] = "again";
copy.extra1 = 1;
copy.extra2 = 2;
is(copy[name], "again", `${label}: ${name} can be re-added`);
is(copy.extra1, 1, `${label}: extra1`);
is(copy.extra2, 2, `${label}: extra2`);
for (let i = 5; i < 8; i++) {
is(copy["x" + i], 1000 + i, `${label}: x${i} survives the adds`);
}
}
add_task(function test_spread() {
for (let trial = 0; trial < 50; trial++) {
const name = "d" + trial;
const { host, collection } = makeCollection(name);
checkCopy({ ...collection }, name, `spread ${trial}`);
host.remove();
}
});
add_task(function test_object_rest() {
for (let trial = 0; trial < 50; trial++) {
const name = "r" + trial;
const { host, collection } = makeCollection(name);
const { notThere, ...rest } = collection;
is(notThere, undefined, "excluded key is not present");
checkCopy(rest, name, `rest ${trial}`);
host.remove();
}
});
add_task(function test_spread_after_literal_entries() {
const name = "lit";
const { host, collection } = makeCollection(name);
const copy = { first: 1, [name]: "literal", ...collection };
const keys = Object.keys(copy);
is(keys.length, new Set(keys).size, `keys are unique: ${keys}`);
const stringKeys = keys.filter(k => isNaN(k));
is(stringKeys[0], "first", "literal entries stay first");
host.remove();
});
</script>
</body>
</html>