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/* Any copyright is dedicated to the Public Domain.
* http://creativecommons.org/licenses/publicdomain/ */
// ES6 19.1.3.6 Object.prototype.toString ( )
function testToString() {
var tests = [
[undefined, "[object Undefined]"],
[null, "[object Null]"],
[[], "[object Array]"],
[new String("abc"), "[object String]"],
[(function () {return arguments;})(), "[object Arguments]"],
[(function () {"use strict"; return arguments;})(), "[object Arguments]"],
[function() {}, "[object Function]"],
[new Error("abc"), "[object Error]"],
[true, "[object Boolean]"],
[5, "[object Number]"],
[new Date(), "[object Date]"],
[/regexp/, "[object RegExp]"],
[{[Symbol.toStringTag]: "abc"}, "[object abc]"],
[Object.create(JSON), "[object JSON]"],
[Object.create(new Number), "[object Object]"],
[Object.create(new Number, {[Symbol.toStringTag]: {value: "abc"}}), "[object abc]"],
[(function() { var x = new Number(); x[Symbol.toStringTag] = "abc"; return x; })(), "[object abc]"],
[[], "[object Array]"]
];
// Testing if the values are obtained the right way.
for (let [value, expected] of tests) {
let result = Object.prototype.toString.call(value);
assertEq(result, expected);
}
}
testToString();
function testProxy() {
var count = 0;
var metaHandler = new Proxy({}, {
get(target, property, receiver) {
assertEq(property, "get");
return function(target, property, receiver) {
assertEq(property, Symbol.toStringTag);
count++;
return undefined;
}
}
});
assertEq(Object.prototype.toString.call(new Proxy({}, metaHandler)), "[object Object]")
assertEq(Object.prototype.toString.call(new Proxy(new Date, metaHandler)), "[object Object]")
assertEq(Object.prototype.toString.call(new Proxy([], metaHandler)), "[object Array]")
assertEq(Object.prototype.toString.call(new Proxy(function() {}, metaHandler)), "[object Function]")
var {proxy, revoke} = Proxy.revocable({}, metaHandler);
revoke();
assertThrowsInstanceOf(() => Object.prototype.toString.call(proxy), TypeError);
assertEq(count, 4);
}
testProxy();
// Tests the passed objects toStringTag values and ensures it's
// desc is writable: false, enumerable: false, configurable: true
function testDefault(object, expected) {
let desc = Object.getOwnPropertyDescriptor(object, Symbol.toStringTag);
assertEq(desc.value, expected);
assertEq(desc.writable, false);
assertEq(desc.enumerable, false);
assertEq(desc.configurable, true);
}
// ES6 19.4.3.5 Symbol.prototype [ @@toStringTag ]
testDefault(Symbol.prototype, "Symbol");
// ES6 20.2.1.9 Math [ @@toStringTag ]
testDefault(Math, "Math");
// ES6 21.1.5.2.2 %StringIteratorPrototype% [ @@toStringTag ]
testDefault(""[Symbol.iterator]().__proto__, "String Iterator")
// ES6 22.1.5.2.2 %ArrayIteratorPrototype% [ @@toStringTag ]
testDefault([][Symbol.iterator]().__proto__, "Array Iterator")
// ES6 22.2.3.31 get %TypedArray%.prototype [ @@toStringTag ]
function testTypedArray() {
let ta = (new Uint8Array(0)).__proto__.__proto__;
let desc = Object.getOwnPropertyDescriptor(ta, Symbol.toStringTag);
assertEq(desc.enumerable, false);
assertEq(desc.configurable, true);
assertEq(desc.set, undefined);
let get = desc.get;
assertEq(get.name, "get [Symbol.toStringTag]");
assertEq(get.call(3.14), undefined);
assertEq(get.call({}), undefined);
assertEq(get.call(ta), undefined);
let types = [
Int8Array,
Uint8Array,
Int16Array,
Uint16Array,
Int32Array,
Uint32Array,
Float32Array,
Float64Array
];
for (let type of types) {
let array = new type(0);
assertEq(get.call(array), type.name);
assertEq(Object.prototype.toString.call(array), `[object ${type.name}]`);
}
}
testTypedArray();
// ES6 23.1.3.13 Map.prototype [ @@toStringTag ]
testDefault(Map.prototype, "Map");
// ES6 23.1.5.2.2 %MapIteratorPrototype% [ @@toStringTag ]
testDefault(new Map()[Symbol.iterator]().__proto__, "Map Iterator")
// ES6 23.2.3.12 Set.prototype [ @@toStringTag ]
testDefault(Set.prototype, "Set");
// ES6 23.2.5.2.2 %SetIteratorPrototype% [ @@toStringTag ]
testDefault(new Set()[Symbol.iterator]().__proto__, "Set Iterator")
// ES6 23.3.3.6 WeakMap.prototype [ @@toStringTag ]
testDefault(WeakMap.prototype, "WeakMap");
// ES6 23.4.3.5 WeakSet.prototype [ @@toStringTag ]
testDefault(WeakSet.prototype, "WeakSet");
// ES6 24.1.4.4 ArrayBuffer.prototype [ @@toStringTag ]
testDefault(ArrayBuffer.prototype, "ArrayBuffer");
// ES6 24.2.4.21 DataView.prototype[ @@toStringTag ]
testDefault(DataView.prototype, "DataView");
// ES6 24.3.3 JSON [ @@toStringTag ]
testDefault(JSON, "JSON");
// ES6 25.2.3.3 GeneratorFunction.prototype [ @@toStringTag ]
testDefault(function* () {}.constructor.prototype, "GeneratorFunction");
// ES6 25.3.1.5 Generator.prototype [ @@toStringTag ]
testDefault(function* () {}().__proto__.__proto__, "Generator");
// ES6 25.4.5.4 Promise.prototype [ @@toStringTag ]
testDefault(Promise.prototype, "Promise");
// AsyncFunction.prototype [ @@toStringTag ]
testDefault(async function() {}.constructor.prototype, "AsyncFunction");
reportCompare(true, true);
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