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// Copyright 2015 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
var global = this;
var funs = {
Object: [ Object ],
Function: [ Function ],
Array: [ Array ],
String: [ String ],
Boolean: [ Boolean ],
Number: [ Number ],
Date: [ Date ],
RegExp: [ RegExp ],
Error: [ Error, TypeError, RangeError, SyntaxError, ReferenceError,
EvalError, URIError ]
};
for (var f in funs) {
for (var i in funs[f]) {
assertEquals("[object " + f + "]",
Object.prototype.toString.call(new funs[f][i]),
funs[f][i]);
assertEquals("[object Function]",
Object.prototype.toString.call(funs[f][i]),
funs[f][i]);
}
}
function testToStringTag(className) {
// Using builtin toStringTags
var obj = {};
obj[Symbol.toStringTag] = className;
assertEquals("[object " + className + "]",
Object.prototype.toString.call(obj));
// Getter throws
obj = {};
Object.defineProperty(obj, Symbol.toStringTag, {
get: function() { throw className; }
});
assertThrowsEquals(function() {
Object.prototype.toString.call(obj);
}, className);
// Getter does not throw
obj = {};
Object.defineProperty(obj, Symbol.toStringTag, {
get: function() { return className; }
});
assertEquals("[object " + className + "]",
Object.prototype.toString.call(obj));
// Custom, non-builtin toStringTags
obj = {};
obj[Symbol.toStringTag] = "X" + className;
assertEquals("[object X" + className + "]",
Object.prototype.toString.call(obj));
// With getter
obj = {};
Object.defineProperty(obj, Symbol.toStringTag, {
get: function() { return "X" + className; }
});
assertEquals("[object X" + className + "]",
Object.prototype.toString.call(obj));
// Undefined toStringTag should return [object className]
var obj = className === "Arguments" ?
(function() { return arguments; })() : new global[className];
obj[Symbol.toStringTag] = undefined;
assertEquals("[object " + className + "]",
Object.prototype.toString.call(obj));
// With getter
var obj = className === "Arguments" ?
(function() { return arguments; })() : new global[className];
Object.defineProperty(obj, Symbol.toStringTag, {
get: function() { return undefined; }
});
assertEquals("[object " + className + "]",
Object.prototype.toString.call(obj));
}
[
"Arguments",
"Array",
"Boolean",
"Date",
"Error",
"Function",
"Number",
"RegExp",
"String"
].forEach(testToStringTag);
function testToStringTagNonString(value) {
var obj = {};
obj[Symbol.toStringTag] = value;
assertEquals("[object Object]", Object.prototype.toString.call(obj));
// With getter
obj = {};
Object.defineProperty(obj, Symbol.toStringTag, {
get: function() { return value; }
});
assertEquals("[object Object]", Object.prototype.toString.call(obj));
}
[
null,
function() {},
[],
{},
/regexp/,
42,
Symbol("sym"),
new Date(),
(function() { return arguments; })(),
true,
new Error("oops"),
new String("str")
].forEach(testToStringTagNonString);
function testObjectToStringPropertyDesc() {
var desc = Object.getOwnPropertyDescriptor(Object.prototype, "toString");
assertTrue(desc.writable);
assertFalse(desc.enumerable);
assertTrue(desc.configurable);
}
testObjectToStringPropertyDesc();
function testObjectToStringOnNonStringValue(obj) {
Object.defineProperty(obj, Symbol.toStringTag, { value: 1 });
assertEquals("[object Object]", ({}).toString.call(obj));
}
testObjectToStringOnNonStringValue({});
// Proxies
function assertTag(tag, obj) {
assertEquals("[object " + tag + "]", Object.prototype.toString.call(obj));
}
assertTag("Object", new Proxy({}, {}));
assertTag("Array", new Proxy([], {}));
assertTag("Function", new Proxy(() => 42, {}));
assertTag("Foo", new Proxy(() => 42, {get() {return "Foo"}}));
assertTag("Function", new Proxy(() => 42, {get() {return 666}}));
var revocable = Proxy.revocable([], {});
revocable.revoke();
assertThrows(() => Object.prototype.toString.call(revocable.proxy), TypeError);
var handler = {};
revocable = Proxy.revocable([], handler);
// The first get() call, i.e., toString() revokes the proxy
handler.get = () => revocable.revoke();
assertEquals("[object Array]", Object.prototype.toString.call(revocable.proxy));
assertThrows(() => Object.prototype.toString.call(revocable.proxy), TypeError);
revocable = Proxy.revocable([], handler);
handler.get = () => {revocable.revoke(); return "value";};
assertEquals("[object value]", Object.prototype.toString.call(revocable.proxy));
assertThrows(() => Object.prototype.toString.call(revocable.proxy), TypeError);
revocable = Proxy.revocable(function() {}, handler);
handler.get = () => revocable.revoke();
assertEquals("[object Function]", Object.prototype.toString.call(revocable.proxy));
assertThrows(() => Object.prototype.toString.call(revocable.proxy), TypeError);
function* gen() { yield 1; }
assertTag("GeneratorFunction", gen);
Object.defineProperty(gen, Symbol.toStringTag, {writable: true});
gen[Symbol.toStringTag] = "different string";
assertTag("different string", gen);
gen[Symbol.toStringTag] = 1;
assertTag("Function", gen);
function overwriteToStringTagWithNonStringValue(tag, obj) {
assertTag(tag, obj);
Object.defineProperty(obj, Symbol.toStringTag, {
configurable: true,
value: "different string"
});
assertTag("different string", obj);
testObjectToStringOnNonStringValue(obj);
}
overwriteToStringTagWithNonStringValue("global", global);
overwriteToStringTagWithNonStringValue("Generator", gen());
var arrayBuffer = new ArrayBuffer();
overwriteToStringTagWithNonStringValue("ArrayBuffer", arrayBuffer);
overwriteToStringTagWithNonStringValue("DataView", new DataView(arrayBuffer));
overwriteToStringTagWithNonStringValue("Int8Array", new Int8Array());
overwriteToStringTagWithNonStringValue("Uint8Array", new Uint8Array());
overwriteToStringTagWithNonStringValue("Uint8ClampedArray",
new Uint8ClampedArray());
overwriteToStringTagWithNonStringValue("Int16Array", new Int16Array());
overwriteToStringTagWithNonStringValue("Uint16Array", new Uint16Array());
overwriteToStringTagWithNonStringValue("Int32Array", new Int32Array());
overwriteToStringTagWithNonStringValue("Uint32Array", new Uint32Array());
overwriteToStringTagWithNonStringValue("Float32Array", new Float32Array());
overwriteToStringTagWithNonStringValue("Float64Array", new Float64Array());
var set = new Set();
var map = new Map();
overwriteToStringTagWithNonStringValue("Set", set);
overwriteToStringTagWithNonStringValue("Map", map);
overwriteToStringTagWithNonStringValue("Set Iterator", set[Symbol.iterator]());
overwriteToStringTagWithNonStringValue("Map Iterator", map[Symbol.iterator]());
overwriteToStringTagWithNonStringValue("WeakSet", new WeakSet());
overwriteToStringTagWithNonStringValue("WeakMap", new WeakMap());
overwriteToStringTagWithNonStringValue("Promise", new Promise(function() {}));
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