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// |reftest| shell-option(--enable-new-set-methods) skip-if(!Set.prototype.difference)
assertEq(typeof Set.prototype.difference, "function");
assertDeepEq(Object.getOwnPropertyDescriptor(Set.prototype.difference, "length"), {
value: 1, writable: false, enumerable: false, configurable: true,
});
assertDeepEq(Object.getOwnPropertyDescriptor(Set.prototype.difference, "name"), {
value: "difference", 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]));
}
// Difference of two empty sets is an empty set.
assertSetContainsExactOrderedItems(emptySet.difference(emptySet), []);
assertSetContainsExactOrderedItems(emptySet.difference(emptySetLike), []);
assertSetContainsExactOrderedItems(emptySet.difference(emptyMap), []);
// Test native Set, Set-like, and Map objects.
for (let values of [
[], [1], [1, 2], [1, true, null, {}],
]) {
// Difference with an empty set.
assertSetContainsExactOrderedItems(new Set(values).difference(emptySet), values);
assertSetContainsExactOrderedItems(new Set(values).difference(emptySetLike), values);
assertSetContainsExactOrderedItems(new Set(values).difference(emptyMap), values);
assertSetContainsExactOrderedItems(emptySet.difference(new Set(values)), []);
assertSetContainsExactOrderedItems(emptySet.difference(new SetLike(values)), []);
assertSetContainsExactOrderedItems(emptySet.difference(asMap(values)), []);
// Two sets with the exact same values.
assertSetContainsExactOrderedItems(new Set(values).difference(new Set(values)), []);
assertSetContainsExactOrderedItems(new Set(values).difference(new SetLike(values)), []);
assertSetContainsExactOrderedItems(new Set(values).difference(asMap(values)), []);
// Difference of the same set object.
let set = new Set(values);
assertSetContainsExactOrderedItems(set.difference(set), []);
}
// 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);
log.length = 0;
assertSetContainsExactOrderedItems(emptySet.difference(setLike), []);
assertEqArray(log, [
"[[get]]", "size",
"valueOf()",
"[[get]]", "has",
"[[get]]", "keys",
]);
// Input has more elements than the this-value.
sizeValue = 1;
log.length = 0;
assertSetContainsExactOrderedItems(emptySet.difference(setLike), []);
assertEqArray(log, [
"[[get]]", "size",
"valueOf()",
"[[get]]", "has",
"[[get]]", "keys",
]);
// Input has fewer elements than the this-value.
sizeValue = 0;
log.length = 0;
assertSetContainsExactOrderedItems(new Set([1]).difference(setLike), [1]);
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;
assertSetContainsExactOrderedItems(emptySet.difference(setLike), []);
assertEqArray(log, [
"[[get]]", "size",
"valueOf()",
"[[get]]", "has",
"[[get]]", "keys",
]);
log.length = 0;
assertThrowsInstanceOf(() => new Set([1]).difference(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;
assertSetContainsExactOrderedItems(emptySet.difference(setLike), []);
assertEqArray(log, [
"[[get]]", "size",
"valueOf()",
"[[get]]", "has",
"[[get]]", "keys",
]);
log.length = 0;
assertThrowsInstanceOf(() => new Set([1]).difference(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.difference(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.difference(setLike), TypeError);
assertEqArray(log, [
"[[get]]", "size",
"valueOf()",
"[[get]]", "has",
]);
// Change |size| to NaN.
sizeValue = NaN;
log.length = 0;
assertThrowsInstanceOf(() => emptySet.difference(setLike), TypeError);
assertEqArray(log, [
"[[get]]", "size",
"valueOf()",
]);
// Change |size| to undefined.
sizeValue = undefined;
log.length = 0;
assertThrowsInstanceOf(() => emptySet.difference(setLike), TypeError);
assertEqArray(log, [
"[[get]]", "size",
"valueOf()",
]);
}
// Doesn't accept Array as an input.
assertThrowsInstanceOf(() => emptySet.difference([]), TypeError);
// Works with Set subclasses.
{
class MySet extends Set {}
let myEmptySet = new MySet;
assertSetContainsExactOrderedItems(emptySet.difference(myEmptySet), []);
assertSetContainsExactOrderedItems(myEmptySet.difference(myEmptySet), []);
assertSetContainsExactOrderedItems(myEmptySet.difference(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.difference.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.difference.call(thisValue, emptySet), TypeError);
}
// Doesn't return the original Set object.
{
let set = new Set([1]);
assertEq(set.difference(emptySet) !== set, true);
assertEq(set.difference(new Set([2])) !== set, true);
}
// Test insertion order
{
let set = new Set([1, 2, 3]);
// Case 1: Input is empty.
assertSetContainsExactOrderedItems(set.difference(new Set([])), [1, 2, 3]);
// Case 2: Input has fewer elements.
assertSetContainsExactOrderedItems(set.difference(new Set([1, 2])), [3]);
assertSetContainsExactOrderedItems(set.difference(new Set([2, 1])), [3]);
assertSetContainsExactOrderedItems(set.difference(new Set([11, 2])), [1, 3]);
assertSetContainsExactOrderedItems(set.difference(new Set([2, 11])), [1, 3]);
// Case 3: Input has same number of elements.
assertSetContainsExactOrderedItems(set.difference(new Set([1, 2, 3])), []);
assertSetContainsExactOrderedItems(set.difference(new Set([2, 3, 1])), []);
assertSetContainsExactOrderedItems(set.difference(new Set([3, 2, 1])), []);
assertSetContainsExactOrderedItems(set.difference(new Set([11, 2, 3])), [1]);
assertSetContainsExactOrderedItems(set.difference(new Set([2, 3, 11])), [1]);
assertSetContainsExactOrderedItems(set.difference(new Set([3, 2, 11])), [1]);
// Case 4: Input has more elements.
assertSetContainsExactOrderedItems(set.difference(new Set([2, 3, 4, 5])), [1]);
assertSetContainsExactOrderedItems(set.difference(new Set([4, 5, 2, 3])), [1]);
assertSetContainsExactOrderedItems(set.difference(new Set([5, 4, 3, 2])), [1]);
}
// Calls |has| when the this-value has fewer or the same number of keys.
{
const keys = [1, 2, 3];
for (let size of [keys.length, 100, Infinity]) {
let i = 0;
let setLike = {
size,
has(v) {
assertEq(this, setLike);
assertEq(arguments.length, 1);
assertEq(i < keys.length, true);
assertEq(v, keys[i++]);
return true;
},
keys() {
throw new Error("Unexpected call to |keys| method");
},
};
assertSetContainsExactOrderedItems(new Set(keys).difference(setLike), []);
}
}
// Calls |keys| when the this-value has more keys.
{
const keys = [1, 2, 3];
for (let size of [0, 1, 2]) {
let i = 0;
let setLike = {
size,
has() {
throw new Error("Unexpected call to |keys| method");
},
keys() {
assertEq(this, setLike);
assertEq(arguments.length, 0);
let iterator = {
next() {
assertEq(this, iterator);
assertEq(arguments.length, 0);
if (i < keys.length) {
return {
done: false,
value: keys[i++],
};
}
return {
done: true,
get value() {
throw new Error("Unexpected call to |value| getter");
},
};
}
};
return iterator;
},
};
assertSetContainsExactOrderedItems(new Set(keys).difference(setLike), []);
}
}
// Test result set order when the this-value was modified.
{
let originalKeys = null;
let setLike = {
size: 100,
has(v) {
if (!originalKeys) {
assertSetContainsExactOrderedItems(set, [1, 2, 3, 4]);
originalKeys = [...set.keys()];
// Remove all existing items.
set.clear();
// Add new keys 11 and 22.
set.add(11);
set.add(22);
}
// |has| is called exactly once for each key.
assertEq(originalKeys.includes(v), true);
originalKeys.splice(originalKeys.indexOf(v), 1);
return true;
},
keys() {
throw new Error("Unexpected call to |keys| method");
},
};
let set = new Set([1, 2, 3, 4]);
assertSetContainsExactOrderedItems(set.difference(setLike), []);
assertSetContainsExactOrderedItems(set, [11, 22]);
assertEqArray(originalKeys, []);
}
{
let setLike = {
size: 0,
has() {
throw new Error("Unexpected call to |has| method");
},
*keys() {
assertSetContainsExactOrderedItems(set, [1, 2, 3, 4]);
let originalKeys = [...set.keys()];
// Remove all existing items.
set.clear();
// Add new keys 11 and 22.
set.add(11);
set.add(22);
// Yield the original keys of |set|.
yield* originalKeys;
},
};
let set = new Set([1, 2, 3, 4]);
assertSetContainsExactOrderedItems(set.difference(setLike), []);
assertSetContainsExactOrderedItems(set, [11, 22]);
}
// 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.difference(other), []);
} 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);