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// |reftest| shell-option(--enable-new-set-methods) skip-if(!Set.prototype.union)
assertEq(typeof Set.prototype.union, "function");
assertDeepEq(Object.getOwnPropertyDescriptor(Set.prototype.union, "length"), {
value: 1, writable: false, enumerable: false, configurable: true,
});
assertDeepEq(Object.getOwnPropertyDescriptor(Set.prototype.union, "name"), {
value: "union", writable: false, enumerable: false, configurable: true,
});
const emptySet = new Set();
const emptySetLike = new SetLike();
const emptyMap = new Map();
function asMap(values) {
return new Map(values.map(v => [v, v]));
}
// Union of two empty sets is an empty set.
assertSetContainsExactOrderedItems(emptySet.union(emptySet), []);
assertSetContainsExactOrderedItems(emptySet.union(emptySetLike), []);
assertSetContainsExactOrderedItems(emptySet.union(emptyMap), []);
// Test native Set, Set-like, and Map objects.
for (let values of [
[], [1], [1, 2], [1, true, null, {}],
]) {
// Union with an empty set.
assertSetContainsExactOrderedItems(new Set(values).union(emptySet), values);
assertSetContainsExactOrderedItems(new Set(values).union(emptySetLike), values);
assertSetContainsExactOrderedItems(new Set(values).union(emptyMap), values);
assertSetContainsExactOrderedItems(emptySet.union(new Set(values)), values);
assertSetContainsExactOrderedItems(emptySet.union(new SetLike(values)), values);
assertSetContainsExactOrderedItems(emptySet.union(asMap(values)), values);
// Two sets with the exact same values.
assertSetContainsExactOrderedItems(new Set(values).union(new Set(values)), values);
assertSetContainsExactOrderedItems(new Set(values).union(new SetLike(values)), values);
assertSetContainsExactOrderedItems(new Set(values).union(asMap(values)), values);
// Union of the same set object.
let set = new Set(values);
assertSetContainsExactOrderedItems(set.union(set), values);
}
// Check property accesses are in the correct order.
{
let log = [];
let sizeValue = 0;
let {proxy: keysIter} = LoggingProxy({
next() {
log.push("next()");
return {done: true};
}
}, log);
let {proxy: setLike} = LoggingProxy({
size: {
valueOf() {
log.push("valueOf()");
return sizeValue;
}
},
has() {
throw new Error("Unexpected call to |has| method");
},
keys() {
log.push("keys()");
return keysIter;
},
}, log);
assertSetContainsExactOrderedItems(emptySet.union(setLike), []);
assertEqArray(log, [
"[[get]]", "size",
"valueOf()",
"[[get]]", "has",
"[[get]]", "keys",
"keys()",
"[[get]]", "next",
"next()",
]);
}
// Check input validation.
{
let log = [];
const nonCallable = {};
let sizeValue = 0;
let {proxy: keysIter} = LoggingProxy({
next: nonCallable,
}, log);
let {proxy: setLike, obj: setLikeObj} = LoggingProxy({
size: {
valueOf() {
log.push("valueOf()");
return sizeValue;
}
},
has() {
throw new Error("Unexpected call to |has| method");
},
keys() {
log.push("keys()");
return keysIter;
},
}, log);
log.length = 0;
assertThrowsInstanceOf(() => emptySet.union(setLike), TypeError);
assertEqArray(log, [
"[[get]]", "size",
"valueOf()",
"[[get]]", "has",
"[[get]]", "keys",
"keys()",
"[[get]]", "next",
]);
// Change |keys| to return a non-object value.
setLikeObj.keys = () => 123;
log.length = 0;
assertThrowsInstanceOf(() => emptySet.union(setLike), TypeError);
assertEqArray(log, [
"[[get]]", "size",
"valueOf()",
"[[get]]", "has",
"[[get]]", "keys",
]);
// Change |keys| to a non-callable value.
setLikeObj.keys = nonCallable;
log.length = 0;
assertThrowsInstanceOf(() => emptySet.union(setLike), TypeError);
assertEqArray(log, [
"[[get]]", "size",
"valueOf()",
"[[get]]", "has",
"[[get]]", "keys",
]);
// Change |has| to a non-callable value.
setLikeObj.has = nonCallable;
log.length = 0;
assertThrowsInstanceOf(() => emptySet.union(setLike), TypeError);
assertEqArray(log, [
"[[get]]", "size",
"valueOf()",
"[[get]]", "has",
]);
// Change |size| to NaN.
sizeValue = NaN;
log.length = 0;
assertThrowsInstanceOf(() => emptySet.union(setLike), TypeError);
assertEqArray(log, [
"[[get]]", "size",
"valueOf()",
]);
// Change |size| to undefined.
sizeValue = undefined;
log.length = 0;
assertThrowsInstanceOf(() => emptySet.union(setLike), TypeError);
assertEqArray(log, [
"[[get]]", "size",
"valueOf()",
]);
}
// Doesn't accept Array as an input.
assertThrowsInstanceOf(() => emptySet.union([]), TypeError);
// Works with Set subclasses.
{
class MySet extends Set {}
let myEmptySet = new MySet;
assertSetContainsExactOrderedItems(emptySet.union(myEmptySet), []);
assertSetContainsExactOrderedItems(myEmptySet.union(myEmptySet), []);
assertSetContainsExactOrderedItems(myEmptySet.union(emptySet), []);
}
// Doesn't access any properties on the this-value.
{
let log = [];
let {proxy: setProto} = LoggingProxy(Set.prototype, log);
let set = new Set([1, 2, 3]);
Object.setPrototypeOf(set, setProto);
assertSetContainsExactOrderedItems(Set.prototype.union.call(set, emptySet), [1, 2, 3]);
assertEqArray(log, []);
}
// Throws a TypeError when the this-value isn't a Set object.
for (let thisValue of [
null, undefined, true, "", {}, new Map, new Proxy(new Set, {}),
]) {
assertThrowsInstanceOf(() => Set.prototype.union.call(thisValue, emptySet), TypeError);
}
// Doesn't return the original Set object.
{
let set = new Set([1]);
assertEq(set.union(emptySet) !== set, true);
assertEq(set.union(new Set([2])) !== set, true);
}
// Test insertion order
{
let set = new Set([1, 2]);
// Case 1: Input is empty.
assertSetContainsExactOrderedItems(set.union(new Set([])), [1, 2]);
// Case 2: Input has fewer elements.
assertSetContainsExactOrderedItems(set.union(new Set([3])), [1, 2, 3]);
// Case 3: Input has same number of elements.
assertSetContainsExactOrderedItems(set.union(new Set([3, 4])), [1, 2, 3, 4]);
// Case 4: Input has more elements.
assertSetContainsExactOrderedItems(set.union(new Set([3, 4, 5])), [1, 2, 3, 4, 5]);
}
// Test that the input set is copied after accessing the |next| property of the keys iterator.
{
let set = new Set([1, 2, 3]);
let setLike = {
size: 0,
has() {
throw new Error("Unexpected call to |has| method");
},
keys() {
return {
get next() {
// Clear the set when getting the |next| method.
set.clear();
// And then add a single new key.
set.add(4);
return function() {
return {done: true};
};
}
};
},
};
// The result should consist of the single, newly added key.
assertSetContainsExactOrderedItems(set.union(setLike), [4]);
}
// Tests which modify any built-ins should appear last, because modifications may disable
// optimised code paths.
// Doesn't call the built-in |Set.prototype.{has, keys, size}| functions.
const SetPrototypeHas = Object.getOwnPropertyDescriptor(Set.prototype, "has");
const SetPrototypeKeys = Object.getOwnPropertyDescriptor(Set.prototype, "keys");
const SetPrototypeSize = Object.getOwnPropertyDescriptor(Set.prototype, "size");
delete Set.prototype.has;
delete Set.prototype.keys;
delete Set.prototype.size;
try {
let set = new Set([1, 2, 3]);
let other = new SetLike([1, 2, 3]);
assertSetContainsExactOrderedItems(set.union(other), [1, 2, 3]);
} finally {
Object.defineProperty(Set.prototype, "has", SetPrototypeHas);
Object.defineProperty(Set.prototype, "keys", SetPrototypeKeys);
Object.defineProperty(Set.prototype, "size", SetPrototypeSize);
}
if (typeof reportCompare === "function")
reportCompare(true, true);