Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

97 files changed, 2145 insertions, 0 deletions

diff --git a/js/src/tests/test262/built-ins/WeakSet/add-not-callable-throws.js b/js/src/tests/test262/built-ins/WeakSet/add-not-callable-throws.js
new file mode 100644
index 0000000000..54f29d1fe0
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/add-not-callable-throws.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset-iterable
+description: >
+  Throws TypeError if add is not callable on constructor call.
+info: |
+  23.4.1.1 WeakSet ( [ iterable ] )
+
+  ...
+  5. If iterable is not present, let iterable be undefined.
+  6. If iterable is either undefined or null, let iter be undefined.
+  7. Else,
+    a. Let adder be Get(set, "add").
+    b. ReturnIfAbrupt(adder).
+    c. If IsCallable(adder) is false, throw a TypeError exception.
+  ...
+---*/
+
+WeakSet.prototype.add = null;
+new WeakSet();
+
+assert.throws(TypeError, function() {
+  new WeakSet([]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/browser.js b/js/src/tests/test262/built-ins/WeakSet/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/browser.js
diff --git a/js/src/tests/test262/built-ins/WeakSet/constructor.js b/js/src/tests/test262/built-ins/WeakSet/constructor.js
new file mode 100644
index 0000000000..21e8e80f7e
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/constructor.js
@@ -0,0 +1,15 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset-constructor
+description: >
+  The WeakSet constructor is the %WeakSet% intrinsic object and the initial
+  value of the WeakSet property of the global object.
+---*/
+
+assert.sameValue(
+  typeof WeakSet, 'function',
+  'typeof WeakSet is "function"'
+);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/empty-iterable.js b/js/src/tests/test262/built-ins/WeakSet/empty-iterable.js
new file mode 100644
index 0000000000..41ec8a90f7
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/empty-iterable.js
@@ -0,0 +1,33 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset-iterable
+description: >
+  If the iterable argument is empty, return new Weakset object.
+info: |
+  23.4.1.1 WeakSet ( [ iterable ] )
+
+  ...
+  9. Repeat
+    a. Let next be IteratorStep(iter).
+    b. ReturnIfAbrupt(next).
+    c. If next is false, return set.
+  ...
+---*/
+
+var counter = 0;
+var add = WeakSet.prototype.add;
+WeakSet.prototype.add = function(value) {
+  counter++;
+  return add.call(this, value);
+};
+var set = new WeakSet([]);
+
+assert.sameValue(Object.getPrototypeOf(set), WeakSet.prototype);
+assert(set instanceof WeakSet);
+assert.sameValue(
+  counter, 0,
+  'empty iterable does not call WeakSet.prototype.add'
+);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/get-add-method-failure.js b/js/src/tests/test262/built-ins/WeakSet/get-add-method-failure.js
new file mode 100644
index 0000000000..f81704d2fe
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/get-add-method-failure.js
@@ -0,0 +1,32 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset-iterable
+description: >
+  Return abrupt after getting `add` method.
+info: |
+  23.4.1.1 WeakSet ( [ iterable ] )
+
+  ...
+  5. If iterable is not present, let iterable be undefined.
+  6. If iterable is either undefined or null, let iter be undefined.
+  7. Else,
+    a. Let adder be Get(set, "add").
+    b. ReturnIfAbrupt(adder).
+    ...
+---*/
+
+Object.defineProperty(WeakSet.prototype, 'add', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+
+new WeakSet();
+new WeakSet(null);
+
+assert.throws(Test262Error, function() {
+  new WeakSet([]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/is-a-constructor.js b/js/src/tests/test262/built-ins/WeakSet/is-a-constructor.js
new file mode 100644
index 0000000000..c8cdc19cb9
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/is-a-constructor.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2020 Rick Waldron. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-ecmascript-standard-built-in-objects
+description: >
+  The WeakSet constructor implements [[Construct]]
+info: |
+  IsConstructor ( argument )
+
+  The abstract operation IsConstructor takes argument argument (an ECMAScript language value).
+  It determines if argument is a function object with a [[Construct]] internal method.
+  It performs the following steps when called:
+
+  If Type(argument) is not Object, return false.
+  If argument has a [[Construct]] internal method, return true.
+  Return false.
+includes: [isConstructor.js]
+features: [Reflect.construct, WeakSet]
+---*/
+
+assert.sameValue(isConstructor(WeakSet), true, 'isConstructor(WeakSet) must return true');
+new WeakSet();
+  
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/iterable-failure.js b/js/src/tests/test262/built-ins/WeakSet/iterable-failure.js
new file mode 100644
index 0000000000..87dc051cad
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/iterable-failure.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset-iterable
+description: >
+  If the iterable argument is undefined, return new Weakset object.
+info: |
+  23.4.1.1 WeakSet ( [ iterable ] )
+
+  ...
+  7. Else,
+    d. Let iter be GetIterator(iterable).
+    e. ReturnIfAbrupt(iter).
+  ...
+---*/
+
+assert.throws(TypeError, function() {
+  new WeakSet({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/iterable-with-object-values.js b/js/src/tests/test262/built-ins/WeakSet/iterable-with-object-values.js
new file mode 100644
index 0000000000..e5510b1455
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/iterable-with-object-values.js
@@ -0,0 +1,31 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset-iterable
+description: >
+  Returns the new WeakSet adding Object values from the iterable parameter.
+info: |
+  WeakSet ( [ _iterable_ ] )
+  8. Repeat,
+    d. Let _status_ be Completion(Call(_adder_, _set_, « _nextValue_ »)).
+
+  WeakSet.prototype.add ( _value_ ):
+  6. Append _value_ as the last element of _entries_.
+features: [WeakSet]
+---*/
+
+var first = {};
+var second = {};
+var added = [];
+var add = WeakSet.prototype.add;
+WeakSet.prototype.add = function(value) {
+  added.push(value);
+  return add.call(this, value);
+};
+var s = new WeakSet([first, second]);
+
+assert.sameValue(added.length, 2, 'Called WeakSet#add for each object');
+assert.sameValue(added[0], first, 'Adds object in order - first');
+assert.sameValue(added[1], second, 'Adds object in order - second');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/iterable-with-symbol-values.js b/js/src/tests/test262/built-ins/WeakSet/iterable-with-symbol-values.js
new file mode 100644
index 0000000000..a3e1263b6f
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/iterable-with-symbol-values.js
@@ -0,0 +1,37 @@
+// |reftest| skip -- symbols-as-weakmap-keys is not supported
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset-iterable
+description: >
+  Returns the new WeakSet adding Symbol values from the iterable parameter.
+info: |
+  WeakSet ( [ _iterable_ ] )
+  8. Repeat,
+    d. Let _status_ be Completion(Call(_adder_, _set_, « _nextValue_ »)).
+
+  WeakSet.prototype.add ( _value_ ):
+  6. Append _value_ as the last element of _entries_.
+features: [Symbol, WeakSet, symbols-as-weakmap-keys]
+includes: [compareArray.js]
+---*/
+
+var first = Symbol('a description');
+var second = Symbol('a description');
+var added = [];
+var realAdd = WeakSet.prototype.add;
+WeakSet.prototype.add = function(value) {
+  added.push(value);
+  return realAdd.call(this, value);
+};
+var s = new WeakSet([first, second, Symbol.hasInstance]);
+
+assert.compareArray(
+  added,
+  [first, second, Symbol.hasInstance],
+  "add() was called 3 times, on the two unregistered and one well-known symbols in order"
+);
+
+WeakSet.prototype.add = realAdd;
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/iterator-close-after-add-failure.js b/js/src/tests/test262/built-ins/WeakSet/iterator-close-after-add-failure.js
new file mode 100644
index 0000000000..90b8e8e813
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/iterator-close-after-add-failure.js
@@ -0,0 +1,45 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset-iterable
+description: >
+  Return IteratorClose(iter, status) if fail on adding value on constructing.
+info: |
+  WeakSet ( [ iterable ] )
+
+  ...
+  9. Repeat
+    f. Let status be Call(adder, set, «nextValue»).
+    g. If status is an abrupt completion, return IteratorClose(iter, status).
+features: [Symbol.iterator]
+---*/
+
+var count = 0;
+var iterable = {};
+iterable[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return {
+        value: null,
+        done: false
+      };
+    },
+    return: function() {
+      count += 1;
+    }
+  };
+};
+WeakSet.prototype.add = function() {
+  throw new Test262Error();
+};
+
+assert.throws(Test262Error, function() {
+  new WeakSet(iterable);
+});
+
+assert.sameValue(
+  count, 1,
+  'The iterator is closed when `WeakSet.prototype.add` throws an error.'
+);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/iterator-next-failure.js b/js/src/tests/test262/built-ins/WeakSet/iterator-next-failure.js
new file mode 100644
index 0000000000..12925e2cb7
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/iterator-next-failure.js
@@ -0,0 +1,31 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset-iterable
+description: >
+  Return abrupt from next iterator step.
+info: |
+  23.4.1.1 WeakSet ( [ iterable ] )
+
+  ...
+  9. Repeat
+    a. Let next be IteratorStep(iter).
+    b. ReturnIfAbrupt(next).
+    ...
+features: [Symbol.iterator]
+---*/
+
+var iterable = {};
+iterable[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      throw new Test262Error();
+    }
+  };
+};
+
+assert.throws(Test262Error, function() {
+  new WeakSet(iterable);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/iterator-value-failure.js b/js/src/tests/test262/built-ins/WeakSet/iterator-value-failure.js
new file mode 100644
index 0000000000..284145a05d
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/iterator-value-failure.js
@@ -0,0 +1,37 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset-iterable
+description: >
+  If the iterable argument is empty, return new Weakset object.
+info: |
+  23.4.1.1 WeakSet ( [ iterable ] )
+
+  ...
+  9. Repeat
+    ...
+    d. Let nextValue be IteratorValue(next).
+    e. ReturnIfAbrupt(nextValue).
+features: [Symbol.iterator]
+---*/
+
+var count = 0;
+var iterable = {};
+iterable[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return {
+        get value() {
+          throw new Test262Error();
+        },
+        done: false
+      };
+    }
+  };
+};
+
+assert.throws(Test262Error, function() {
+  new WeakSet(iterable);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/length.js b/js/src/tests/test262/built-ins/WeakSet/length.js
new file mode 100644
index 0000000000..a34c33236d
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/length.js
@@ -0,0 +1,16 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-properties-of-the-weakset-constructor
+description: >
+  The length property of the WeakSet constructor is 0.
+includes: [propertyHelper.js]
+---*/
+
+assert.sameValue(WeakSet.length, 0, 'The value of `WeakSet.length` is `0`');
+
+verifyNotEnumerable(WeakSet, 'length');
+verifyNotWritable(WeakSet, 'length');
+verifyConfigurable(WeakSet, 'length');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/name.js b/js/src/tests/test262/built-ins/WeakSet/name.js
new file mode 100644
index 0000000000..dedd6f4fd0
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/name.js
@@ -0,0 +1,22 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset-iterable
+description: >
+    WeakSet ( [ iterable ] )
+
+    17 ECMAScript Standard Built-in Objects
+
+includes: [propertyHelper.js]
+---*/
+
+assert.sameValue(
+  WeakSet.name, 'WeakSet',
+  'The value of `WeakSet.name` is "WeakSet"'
+);
+
+verifyNotEnumerable(WeakSet, 'name');
+verifyNotWritable(WeakSet, 'name');
+verifyConfigurable(WeakSet, 'name');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/no-iterable.js b/js/src/tests/test262/built-ins/WeakSet/no-iterable.js
new file mode 100644
index 0000000000..6413080507
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/no-iterable.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset-iterable
+description: >
+  If the iterable argument is undefined, return new Weakset object.
+info: |
+  23.4.1.1 WeakSet ( [ iterable ] )
+
+  ...
+  5. If iterable is not present, let iterable be undefined.
+  6. If iterable is either undefined or null, let iter be undefined.
+  ...
+  8. If iter is undefined, return set.
+  ...
+---*/
+
+var a = new WeakSet();
+var b = new WeakSet(undefined);
+var c = new WeakSet(null);
+
+assert.sameValue(Object.getPrototypeOf(a), WeakSet.prototype);
+assert.sameValue(Object.getPrototypeOf(b), WeakSet.prototype);
+assert.sameValue(Object.getPrototypeOf(c), WeakSet.prototype);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/properties-of-the-weakset-prototype-object.js b/js/src/tests/test262/built-ins/WeakSet/properties-of-the-weakset-prototype-object.js
new file mode 100644
index 0000000000..26f93b89c0
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/properties-of-the-weakset-prototype-object.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-properties-of-the-weakset-prototype-object
+description: >
+  The WeakSet.prototype's prototype is Object.prototype.
+info: |
+  23.4.3 Properties of the WeakSet Prototype Object
+
+  The WeakSet prototype object is the intrinsic object %WeakSetPrototype%. The
+  value of the [[Prototype]] internal slot of the WeakSet prototype object is
+  the intrinsic object %ObjectPrototype% (19.1.3). The WeakSet prototype
+  object is an ordinary object. It does not have a [[WeakSetData]] internal
+  slot.
+---*/
+
+assert.sameValue(
+  Object.getPrototypeOf(WeakSet.prototype),
+  Object.prototype,
+  '`Object.getPrototypeOf(WeakSet.prototype)` returns `Object.prototype`'
+);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/proto-from-ctor-realm.js b/js/src/tests/test262/built-ins/WeakSet/proto-from-ctor-realm.js
new file mode 100644
index 0000000000..94a58c6e7e
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/proto-from-ctor-realm.js
@@ -0,0 +1,31 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset-iterable
+description: Default [[Prototype]] value derived from realm of the newTarget
+info: |
+    [...]
+    2. Let set be ? OrdinaryCreateFromConstructor(NewTarget,
+       "%WeakSetPrototype%", « [[WeakSetData]] »).
+    [...]
+
+    9.1.14 GetPrototypeFromConstructor
+
+    [...]
+    3. Let proto be ? Get(constructor, "prototype").
+    4. If Type(proto) is not Object, then
+       a. Let realm be ? GetFunctionRealm(constructor).
+       b. Let proto be realm's intrinsic object named intrinsicDefaultProto.
+    [...]
+features: [cross-realm, Reflect]
+---*/
+
+var other = $262.createRealm().global;
+var C = new other.Function();
+C.prototype = null;
+
+var o = Reflect.construct(WeakSet, [], C);
+
+assert.sameValue(Object.getPrototypeOf(o), other.WeakSet.prototype);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype-of-weakset.js b/js/src/tests/test262/built-ins/WeakSet/prototype-of-weakset.js
new file mode 100644
index 0000000000..f46134d487
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype-of-weakset.js
@@ -0,0 +1,16 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-properties-of-the-weakset-constructor
+description: >
+  The value of the [[Prototype]] internal slot of the WeakSet constructor
+  is the intrinsic object %FunctionPrototype% (19.2.3).
+---*/
+
+assert.sameValue(
+  Object.getPrototypeOf(WeakSet),
+  Function.prototype,
+  '`Object.getPrototypeOf(WeakSet)` returns `Function.prototype`'
+);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/Symbol.toStringTag.js b/js/src/tests/test262/built-ins/WeakSet/prototype/Symbol.toStringTag.js
new file mode 100644
index 0000000000..46283bf20b
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/Symbol.toStringTag.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype-@@tostringtag
+description: >
+    `Symbol.toStringTag` property descriptor
+info: |
+    The initial value of the @@toStringTag property is the String value
+    "WeakSet".
+
+    This property has the attributes { [[Writable]]: false, [[Enumerable]]:
+    false, [[Configurable]]: true }.
+includes: [propertyHelper.js]
+features: [Symbol.toStringTag]
+---*/
+
+assert.sameValue(WeakSet.prototype[Symbol.toStringTag], 'WeakSet');
+
+verifyNotEnumerable(WeakSet.prototype, Symbol.toStringTag);
+verifyNotWritable(WeakSet.prototype, Symbol.toStringTag);
+verifyConfigurable(WeakSet.prototype, Symbol.toStringTag);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/add.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/add.js
new file mode 100644
index 0000000000..fdde051296
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/add.js
@@ -0,0 +1,24 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: WeakSet.prototype.add property descriptor
+info: |
+  WeakSet.prototype.add ( value )
+
+  17 ECMAScript Standard Built-in Objects
+
+includes: [propertyHelper.js]
+---*/
+
+assert.sameValue(
+  typeof WeakSet.prototype.add,
+  'function',
+  'typeof WeakSet.prototype.add is "function"'
+);
+
+verifyNotEnumerable(WeakSet.prototype, 'add');
+verifyWritable(WeakSet.prototype, 'add');
+verifyConfigurable(WeakSet.prototype, 'add');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/adds-object-element.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/adds-object-element.js
new file mode 100644
index 0000000000..89c946b923
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/adds-object-element.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: >
+  Adds an Object value.
+info: |
+  WeakSet.prototype.add ( _value_ )
+  6. Append _value_ as the last element of _entries_.
+features: [WeakSet]
+---*/
+
+var s = new WeakSet();
+var foo = {};
+var bar = {};
+var baz = {};
+
+s.add(foo);
+s.add(bar);
+s.add(baz);
+
+assert(s.has(foo));
+assert(s.has(bar));
+assert(s.has(baz));
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/adds-symbol-element.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/adds-symbol-element.js
new file mode 100644
index 0000000000..9b91ce876d
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/adds-symbol-element.js
@@ -0,0 +1,27 @@
+// |reftest| skip -- symbols-as-weakmap-keys is not supported
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: Adds a Symbol value.
+info: |
+  WeakSet.prototype.add ( _value_ )
+  6. Append _value_ as the last element of _entries_.
+features: [Symbol, WeakSet, symbols-as-weakmap-keys]
+---*/
+
+var s = new WeakSet();
+var foo = Symbol('a description');
+var bar = Symbol('a description');
+var baz = Symbol('a different description');
+
+s.add(foo);
+s.add(baz);
+s.add(Symbol.hasInstance);
+
+assert(s.has(foo), 'Regular symbol');
+assert(!s.has(bar), "Symbols with the same description don't alias each other");
+assert(s.has(baz), 'Regular symbol with different description');
+assert(s.has(Symbol.hasInstance), 'Well-known symbol');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/browser.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/browser.js
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/does-not-have-weaksetdata-internal-slot-array.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/does-not-have-weaksetdata-internal-slot-array.js
new file mode 100644
index 0000000000..ad6734e3dd
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/does-not-have-weaksetdata-internal-slot-array.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: >
+  Throws TypeError if context doesn't have a [[WeakSetData]] internal slot.
+info: |
+  WeakSet.prototype.add ( value )
+
+  ...
+  3. If S does not have a [[WeakSetData]] internal slot, throw a TypeError
+  exception.
+  ...
+
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.add.call([], {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.add.call([], {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/does-not-have-weaksetdata-internal-slot-map.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/does-not-have-weaksetdata-internal-slot-map.js
new file mode 100644
index 0000000000..7b8a340c4b
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/does-not-have-weaksetdata-internal-slot-map.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: >
+  Throws TypeError if context doesn't have a [[WeakSetData]] internal slot.
+info: |
+  WeakSet.prototype.add ( value )
+
+  ...
+  3. If S does not have a [[WeakSetData]] internal slot, throw a TypeError
+  exception.
+  ...
+
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.add.call(new Map(), {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.add.call(new Map(), {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/does-not-have-weaksetdata-internal-slot-object.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/does-not-have-weaksetdata-internal-slot-object.js
new file mode 100644
index 0000000000..3b54921c00
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/does-not-have-weaksetdata-internal-slot-object.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: >
+  Throws TypeError if context doesn't have a [[WeakSetData]] internal slot.
+info: |
+  WeakSet.prototype.add ( value )
+
+  ...
+  3. If S does not have a [[WeakSetData]] internal slot, throw a TypeError
+  exception.
+  ...
+
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.add.call({}, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.add.call({}, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/does-not-have-weaksetdata-internal-slot-set.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/does-not-have-weaksetdata-internal-slot-set.js
new file mode 100644
index 0000000000..93c7bbb218
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/does-not-have-weaksetdata-internal-slot-set.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: >
+  Throws TypeError if context doesn't have a [[WeakSetData]] internal slot.
+info: |
+  WeakSet.prototype.add ( value )
+
+  ...
+  3. If S does not have a [[WeakSetData]] internal slot, throw a TypeError
+  exception.
+  ...
+features: [Set]
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.add.call(new Set(), {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.add.call(new Set(), {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/does-not-have-weaksetdata-internal-slot-weakset-prototype.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/does-not-have-weaksetdata-internal-slot-weakset-prototype.js
new file mode 100644
index 0000000000..947d16e2fa
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/does-not-have-weaksetdata-internal-slot-weakset-prototype.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: >
+  Throws TypeError if context doesn't have a [[WeakSetData]] internal slot.
+info: |
+  WeakSet.prototype.add ( value )
+
+  ...
+  3. If S does not have a [[WeakSetData]] internal slot, throw a TypeError
+  exception.
+  ...
+
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.add.call(WeakSet.prototype, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.add.call(WeakSet.prototype, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/length.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/length.js
new file mode 100644
index 0000000000..7112319f12
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/length.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: WeakSet.prototype.add.length descriptor
+info: |
+  WeakSet.prototype.add ( value )
+
+  17 ECMAScript Standard Built-in Objects
+
+includes: [propertyHelper.js]
+---*/
+
+assert.sameValue(
+  WeakSet.prototype.add.length, 1,
+  'The value of `WeakSet.prototype.add.length` is `1`'
+);
+
+verifyNotEnumerable(WeakSet.prototype.add, 'length');
+verifyNotWritable(WeakSet.prototype.add, 'length');
+verifyConfigurable(WeakSet.prototype.add, 'length');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/name.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/name.js
new file mode 100644
index 0000000000..e81470dc1c
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/name.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: WeakSet.prototype.add.name descriptor
+info: |
+  WeakSet.prototype.add ( value )
+
+  17 ECMAScript Standard Built-in Objects
+
+includes: [propertyHelper.js]
+---*/
+
+assert.sameValue(
+  WeakSet.prototype.add.name, 'add',
+  'The value of WeakSet.prototype.add.name is "add"'
+);
+
+verifyNotEnumerable(WeakSet.prototype.add, 'name');
+verifyNotWritable(WeakSet.prototype.add, 'name');
+verifyConfigurable(WeakSet.prototype.add, 'name');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/not-a-constructor.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/not-a-constructor.js
new file mode 100644
index 0000000000..df2a033c51
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/not-a-constructor.js
@@ -0,0 +1,35 @@
+// Copyright (C) 2020 Rick Waldron. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-ecmascript-standard-built-in-objects
+description: >
+  WeakSet.prototype.add does not implement [[Construct]], is not new-able
+info: |
+  ECMAScript Function Objects
+
+  Built-in function objects that are not identified as constructors do not
+  implement the [[Construct]] internal method unless otherwise specified in
+  the description of a particular function.
+
+  sec-evaluatenew
+
+  ...
+  7. If IsConstructor(constructor) is false, throw a TypeError exception.
+  ...
+includes: [isConstructor.js]
+features: [Reflect.construct, WeakSet, arrow-function]
+---*/
+
+assert.sameValue(
+  isConstructor(WeakSet.prototype.add),
+  false,
+  'isConstructor(WeakSet.prototype.add) must return false'
+);
+
+assert.throws(TypeError, () => {
+  let ws = new WeakSet(); new ws.add({});
+}, '`let ws = new WeakSet(); new ws.add({})` throws TypeError');
+
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/returns-this-symbol.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/returns-this-symbol.js
new file mode 100644
index 0000000000..5e8b67fc06
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/returns-this-symbol.js
@@ -0,0 +1,21 @@
+// |reftest| skip -- symbols-as-weakmap-keys is not supported
+// Copyright (C) 2022 Igalia S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-weakset.prototype.add
+description: Returns `this` after adding a new value.
+info: |
+  WeakSet.prototype.add ( value )
+
+  1. Let S be the this value.
+  ...
+  7. Return S.
+features: [Symbol, WeakSet, symbols-as-weakmap-keys]
+---*/
+
+var s = new WeakSet();
+
+assert.sameValue(s.add(Symbol('description')), s, '`s.add(Symbol("description"))` returns `s`');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/returns-this-when-ignoring-duplicate-symbol.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/returns-this-when-ignoring-duplicate-symbol.js
new file mode 100644
index 0000000000..9b3b269f91
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/returns-this-when-ignoring-duplicate-symbol.js
@@ -0,0 +1,25 @@
+// |reftest| skip -- symbols-as-weakmap-keys is not supported
+// Copyright (C) 2022 Igalia S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-weakset.prototype.add
+description: Returns `this` when new value is duplicate.
+info: |
+  WeakSet.prototype.add ( value )
+
+  1. Let S be the this value.
+  ...
+  5. 5. For each element e of entries, do
+    a. If e is not empty and SameValue(e, value) is true, then
+      i. Return S.
+  ...
+features: [Symbol, WeakSet, symbols-as-weakmap-keys]
+---*/
+
+var foo = Symbol('description');
+var s = new WeakSet([foo]);
+
+assert.sameValue(s.add(foo), s, '`s.add(foo)` returns `s`');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/returns-this-when-ignoring-duplicate.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/returns-this-when-ignoring-duplicate.js
new file mode 100644
index 0000000000..0757a57d08
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/returns-this-when-ignoring-duplicate.js
@@ -0,0 +1,22 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: Returns `this` when new value is duplicate.
+info: |
+  WeakSet.prototype.add ( value )
+
+  1. Let S be this value.
+  ...
+  6. Repeat for each e that is an element of entries,
+    a. If e is not empty and SameValueZero(e, value) is true, then
+    i. Return S.
+  ...
+---*/
+
+var foo = {};
+var s = new WeakSet([foo]);
+
+assert.sameValue(s.add(foo), s, '`s.add(foo)` returns `s`');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/returns-this.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/returns-this.js
new file mode 100644
index 0000000000..36bc5d7ab6
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/returns-this.js
@@ -0,0 +1,19 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: Returns `this` after adding a new value.
+info: |
+  WeakSet.prototype.add ( value )
+
+  1. Let S be this value.
+  ...
+  8. Return S.
+
+---*/
+
+var s = new WeakSet();
+
+assert.sameValue(s.add({}), s, '`s.add({})` returns `s`');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/shell.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/shell.js
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-boolean.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-boolean.js
new file mode 100644
index 0000000000..1e42880bd0
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-boolean.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.add ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.add.call(false, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.add.call(false, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-null.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-null.js
new file mode 100644
index 0000000000..1177ac42d8
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-null.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.add ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.add.call(null, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.add.call(null, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-number.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-number.js
new file mode 100644
index 0000000000..84f4ba33d2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-number.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.add ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.add.call(0, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.add.call(0, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-string.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-string.js
new file mode 100644
index 0000000000..851eabfdce
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-string.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.add ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.add.call('', {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.add.call('', {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-symbol.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-symbol.js
new file mode 100644
index 0000000000..a2346d5ed2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-symbol.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.add ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+features: [Symbol]
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.add.call(Symbol(), {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.add.call(Symbol(), {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-undefined.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-undefined.js
new file mode 100644
index 0000000000..6bb069cc3f
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/this-not-object-throw-undefined.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.add ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.add.call(undefined, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.add.call(undefined, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/add/throw-when-value-cannot-be-held-weakly.js b/js/src/tests/test262/built-ins/WeakSet/prototype/add/throw-when-value-cannot-be-held-weakly.js
new file mode 100644
index 0000000000..d92f3a283b
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/add/throw-when-value-cannot-be-held-weakly.js
@@ -0,0 +1,38 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.add
+description: Throws TypeError if value cannot be held weakly.
+info: |
+  WeakSet.prototype.add ( _value_ )
+  3. If CanBeHeldWeakly(_value_) is *false*, throw a *TypeError* exception.
+features: [Symbol, WeakSet]
+---*/
+
+var s = new WeakSet();
+
+assert.throws(TypeError, function() {
+  s.add(1);
+});
+
+assert.throws(TypeError, function() {
+  s.add(false);
+});
+
+assert.throws(TypeError, function() {
+  s.add();
+});
+
+assert.throws(TypeError, function() {
+  s.add('string');
+});
+
+assert.throws(TypeError, function() {
+  s.add(null);
+});
+
+assert.throws(TypeError, function() {
+  s.add(Symbol.for('registered symbol'));
+}, 'Registered symbol not allowed as WeakSet value');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/browser.js b/js/src/tests/test262/built-ins/WeakSet/prototype/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/browser.js
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/constructor/browser.js b/js/src/tests/test262/built-ins/WeakSet/prototype/constructor/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/constructor/browser.js
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/constructor/shell.js b/js/src/tests/test262/built-ins/WeakSet/prototype/constructor/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/constructor/shell.js
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/constructor/weakset-prototype-constructor-intrinsic.js b/js/src/tests/test262/built-ins/WeakSet/prototype/constructor/weakset-prototype-constructor-intrinsic.js
new file mode 100644
index 0000000000..bc2d887649
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/constructor/weakset-prototype-constructor-intrinsic.js
@@ -0,0 +1,16 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.constructor
+description: >
+  The initial value of WeakSet.prototype.constructor is the %WeakSet%
+  intrinsic object.
+---*/
+
+assert.sameValue(
+  WeakSet.prototype.constructor,
+  WeakSet,
+  'The value of WeakSet.prototype.constructor is "WeakSet"'
+);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/constructor/weakset-prototype-constructor.js b/js/src/tests/test262/built-ins/WeakSet/prototype/constructor/weakset-prototype-constructor.js
new file mode 100644
index 0000000000..4c4867f411
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/constructor/weakset-prototype-constructor.js
@@ -0,0 +1,19 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.constructor
+description: >
+  WeakSet.prototype.constructor property descriptor
+info: |
+  WeakSet ( [ iterable ] )
+
+  17 ECMAScript Standard Built-in Objects
+
+includes: [propertyHelper.js]
+---*/
+
+verifyNotEnumerable(WeakSet.prototype, 'constructor');
+verifyWritable(WeakSet.prototype, 'constructor');
+verifyConfigurable(WeakSet.prototype, 'constructor');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/browser.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/browser.js
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/delete-entry-initial-iterable.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/delete-entry-initial-iterable.js
new file mode 100644
index 0000000000..be17a549fa
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/delete-entry-initial-iterable.js
@@ -0,0 +1,29 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: >
+  Delete an entry from initial iterable.
+info: |
+  WeakSet.prototype.delete ( value )
+
+  ...
+  5. Let entries be the List that is the value of S’s [[WeakSetData]] internal
+  slot.
+  6. Repeat for each e that is an element of entries,
+    a. If e is not empty and SameValue(e, value) is true, then
+    i. Replace the element of entries whose value is e with an element whose
+    value is empty.
+    ii. Return true.
+  ...
+---*/
+
+var foo = {};
+var s = new WeakSet([foo]);
+
+var result = s.delete(foo);
+
+assert.sameValue(s.has(foo), false);
+assert.sameValue(result, true, 'WeakSet#delete returns true');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/delete-object-entry.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/delete-object-entry.js
new file mode 100644
index 0000000000..419c0e9d11
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/delete-object-entry.js
@@ -0,0 +1,28 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: >
+  Delete an entry that is an Object
+info: |
+  WeakSet.prototype.delete ( _value_ )
+  4. Let _entries_ be the List that is _S_.[[WeakSetData]].
+  5. For each element _e_ of _entries_, do
+    a. If _e_ is not ~empty~ and SameValue(_e_, _value_) is *true*, then
+      i. Replace the element of _entries_ whose value is _e_ with an element
+        whose value is ~empty~.
+      ii. Return *true*.
+features: [WeakSet]
+---*/
+
+var foo = {};
+var s = new WeakSet();
+
+s.add(foo);
+
+var result = s.delete(foo);
+
+assert.sameValue(s.has(foo), false);
+assert.sameValue(result, true, 'WeakSet#delete returns true');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/delete-symbol-entry.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/delete-symbol-entry.js
new file mode 100644
index 0000000000..daaa0b0d11
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/delete-symbol-entry.js
@@ -0,0 +1,34 @@
+// |reftest| skip -- symbols-as-weakmap-keys is not supported
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: >
+  Delete an entry that is a Symbol
+info: |
+  WeakSet.prototype.delete ( _value_ )
+  4. Let _entries_ be the List that is _S_.[[WeakSetData]].
+  5. For each element _e_ of _entries_, do
+    a. If _e_ is not ~empty~ and SameValue(_e_, _value_) is *true*, then
+      i. Replace the element of _entries_ whose value is _e_ with an element
+        whose value is ~empty~.
+      ii. Return *true*.
+features: [Symbol, WeakSet, symbols-as-weakmap-keys]
+---*/
+
+var foo = Symbol('a description');
+var bar = Symbol('a description');
+var s = new WeakSet();
+
+s.add(foo);
+s.add(bar);
+s.add(Symbol.hasInstance);
+
+assert.sameValue(s.delete(foo), true, 'Returns true for regular symbol');
+assert(!s.has(foo), 'Regular symbol is removed from set');
+assert(s.has(bar), 'Symbols with the same description are not aliased to each other');
+
+assert.sameValue(s.delete(Symbol.hasInstance), true, 'Returns true for well-known symbol');
+assert(!s.has(Symbol.hasInstance), 'Well-known symbol is removed from set');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/delete.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/delete.js
new file mode 100644
index 0000000000..6a6a0c6567
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/delete.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: >
+  WeakSet.prototype.delete property descriptor
+info: |
+  WeakSet.prototype.delete ( value )
+
+  17 ECMAScript Standard Built-in Objects
+
+includes: [propertyHelper.js]
+---*/
+
+assert.sameValue(
+  typeof WeakSet.prototype.delete,
+  'function',
+  'typeof WeakSet.prototype.delete is "function"'
+);
+
+verifyNotEnumerable(WeakSet.prototype, 'delete');
+verifyWritable(WeakSet.prototype, 'delete');
+verifyConfigurable(WeakSet.prototype, 'delete');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/does-not-have-weaksetdata-internal-slot-array.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/does-not-have-weaksetdata-internal-slot-array.js
new file mode 100644
index 0000000000..85af47a0c5
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/does-not-have-weaksetdata-internal-slot-array.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: >
+  Throws TypeError if context doesn't have a [[WeakSetData]] internal slot.
+info: |
+  WeakSet.prototype.delete ( value )
+
+  ...
+  3. If S does not have a [[WeakSetData]] internal slot, throw a TypeError
+  exception.
+  ...
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.delete.call([], {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.delete.call([], {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/does-not-have-weaksetdata-internal-slot-map.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/does-not-have-weaksetdata-internal-slot-map.js
new file mode 100644
index 0000000000..9b66219774
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/does-not-have-weaksetdata-internal-slot-map.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: >
+  Throws TypeError if context doesn't have a [[WeakSetData]] internal slot.
+info: |
+  WeakSet.prototype.delete ( value )
+
+  ...
+  3. If S does not have a [[WeakSetData]] internal slot, throw a TypeError
+  exception.
+  ...
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.delete.call(new Map(), {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.delete.call(new Map(), {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/does-not-have-weaksetdata-internal-slot-object.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/does-not-have-weaksetdata-internal-slot-object.js
new file mode 100644
index 0000000000..e8a65833cd
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/does-not-have-weaksetdata-internal-slot-object.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: >
+  Throws TypeError if context doesn't have a [[WeakSetData]] internal slot.
+info: |
+  WeakSet.prototype.delete ( value )
+
+  ...
+  3. If S does not have a [[WeakSetData]] internal slot, throw a TypeError
+  exception.
+  ...
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.delete.call({}, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.delete.call({}, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/does-not-have-weaksetdata-internal-slot-set.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/does-not-have-weaksetdata-internal-slot-set.js
new file mode 100644
index 0000000000..a870aacbb5
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/does-not-have-weaksetdata-internal-slot-set.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: >
+  Throws TypeError if context doesn't have a [[WeakSetData]] internal slot.
+info: |
+  WeakSet.prototype.delete ( value )
+
+  ...
+  3. If S does not have a [[WeakSetData]] internal slot, throw a TypeError
+  exception.
+  ...
+features: [Set]
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.delete.call(new Set(), {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.delete.call(new Set(), {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/does-not-have-weaksetdata-internal-slot-weakset-prototype.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/does-not-have-weaksetdata-internal-slot-weakset-prototype.js
new file mode 100644
index 0000000000..a50aa93aa9
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/does-not-have-weaksetdata-internal-slot-weakset-prototype.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: >
+  Throws TypeError if context doesn't have a [[WeakSetData]] internal slot.
+info: |
+  WeakSet.prototype.delete ( value )
+
+  ...
+  3. If S does not have a [[WeakSetData]] internal slot, throw a TypeError
+  exception.
+  ...
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.delete.call(WeakSet.prototype, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.delete.call(WeakSet.prototype, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/length.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/length.js
new file mode 100644
index 0000000000..516b074855
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/length.js
@@ -0,0 +1,24 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: >
+  WeakSet.prototype.delete.length value and writability.
+info: |
+  WeakSet.prototype.delete ( value )
+
+  17 ECMAScript Standard Built-in Objects
+
+includes: [propertyHelper.js]
+---*/
+
+assert.sameValue(
+  WeakSet.prototype.delete.length, 1,
+  'The value of WeakSet.prototype.delete.length is 1'
+);
+
+verifyNotEnumerable(WeakSet.prototype.delete, 'length');
+verifyNotWritable(WeakSet.prototype.delete, 'length');
+verifyConfigurable(WeakSet.prototype.delete, 'length');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/name.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/name.js
new file mode 100644
index 0000000000..b759002e7c
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/name.js
@@ -0,0 +1,24 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: >
+  WeakSet.prototype.delete.name value and writability.
+info: |
+  WeakSet.prototype.delete ( value )
+
+  17 ECMAScript Standard Built-in Objects
+
+includes: [propertyHelper.js]
+---*/
+
+assert.sameValue(
+  WeakSet.prototype.delete.name, 'delete',
+  'The value of WeakSet.prototype.delete.name is "delete"'
+);
+
+verifyNotEnumerable(WeakSet.prototype.delete, 'name');
+verifyNotWritable(WeakSet.prototype.delete, 'name');
+verifyConfigurable(WeakSet.prototype.delete, 'name');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/not-a-constructor.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/not-a-constructor.js
new file mode 100644
index 0000000000..3f5c5605d0
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/not-a-constructor.js
@@ -0,0 +1,35 @@
+// Copyright (C) 2020 Rick Waldron. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-ecmascript-standard-built-in-objects
+description: >
+  WeakSet.prototype.delete does not implement [[Construct]], is not new-able
+info: |
+  ECMAScript Function Objects
+
+  Built-in function objects that are not identified as constructors do not
+  implement the [[Construct]] internal method unless otherwise specified in
+  the description of a particular function.
+
+  sec-evaluatenew
+
+  ...
+  7. If IsConstructor(constructor) is false, throw a TypeError exception.
+  ...
+includes: [isConstructor.js]
+features: [Reflect.construct, WeakSet, arrow-function]
+---*/
+
+assert.sameValue(
+  isConstructor(WeakSet.prototype.delete),
+  false,
+  'isConstructor(WeakSet.prototype.delete) must return false'
+);
+
+assert.throws(TypeError, () => {
+  let ws = new WeakSet(); new ws.delete();
+}, '`let ws = new WeakSet(); new ws.delete()` throws TypeError');
+
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/returns-false-when-delete-is-noop.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/returns-false-when-delete-is-noop.js
new file mode 100644
index 0000000000..a122d06edb
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/returns-false-when-delete-is-noop.js
@@ -0,0 +1,19 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: >
+  Return false if entry wasn't in the WeakSet.
+info: |
+  WeakSet.prototype.delete ( value )
+
+  ...
+  7. Return false.
+
+---*/
+
+var s = new WeakSet();
+
+assert.sameValue(s.delete({}), false);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/returns-false-when-value-cannot-be-held-weakly.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/returns-false-when-value-cannot-be-held-weakly.js
new file mode 100644
index 0000000000..cdffefa60a
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/returns-false-when-value-cannot-be-held-weakly.js
@@ -0,0 +1,22 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: >
+  Return false if value cannot be held weakly.
+info: |
+  WeakSet.prototype.delete ( _value_ )
+  3. If CanBeHeldWeakly(_value_) is *false*, return *false*.
+features: [Symbol, WeakSet]
+---*/
+
+var s = new WeakSet();
+
+assert.sameValue(s.delete(1), false);
+assert.sameValue(s.delete(''), false);
+assert.sameValue(s.delete(null), false);
+assert.sameValue(s.delete(undefined), false);
+assert.sameValue(s.delete(true), false);
+assert.sameValue(s.delete(Symbol.for('registered symbol')), false, 'Registered symbol not allowed as value');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/shell.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/shell.js
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-boolean.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-boolean.js
new file mode 100644
index 0000000000..77b60d78c4
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-boolean.js
@@ -0,0 +1,22 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.delete ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.delete.call(false, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.delete.call(false, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-null.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-null.js
new file mode 100644
index 0000000000..728e010f90
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-null.js
@@ -0,0 +1,22 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.delete ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.delete.call(null, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.delete.call(null, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-number.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-number.js
new file mode 100644
index 0000000000..01a602ee90
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-number.js
@@ -0,0 +1,22 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.delete ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.delete.call(0, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.delete.call(0, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-string.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-string.js
new file mode 100644
index 0000000000..f7e89614b9
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-string.js
@@ -0,0 +1,22 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.delete ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.delete.call('', {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.delete.call('', {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-symbol.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-symbol.js
new file mode 100644
index 0000000000..8e0144c3f9
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-symbol.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.delete ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+features: [Symbol]
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.delete.call(Symbol(), {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.delete.call(Symbol(), {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-undefined.js b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-undefined.js
new file mode 100644
index 0000000000..f0b2b22949
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/delete/this-not-object-throw-undefined.js
@@ -0,0 +1,22 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.delete
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.delete ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.delete.call(undefined, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.delete.call(undefined, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/browser.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/browser.js
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/does-not-have-weaksetdata-internal-slot-array.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/does-not-have-weaksetdata-internal-slot-array.js
new file mode 100644
index 0000000000..daa590bb0b
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/does-not-have-weaksetdata-internal-slot-array.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: >
+  Throws TypeError if context doesn't have a [[WeakSetData]] internal slot.
+info: |
+  WeakSet.prototype.has ( value )
+
+  ...
+  3. If S does not have a [[WeakSetData]] internal slot, throw a TypeError
+  exception.
+  ...
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.has.call([], {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.has.call([], {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/does-not-have-weaksetdata-internal-slot-map.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/does-not-have-weaksetdata-internal-slot-map.js
new file mode 100644
index 0000000000..1d2bc18b93
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/does-not-have-weaksetdata-internal-slot-map.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: >
+  Throws TypeError if context doesn't have a [[WeakSetData]] internal slot.
+info: |
+  WeakSet.prototype.has ( value )
+
+  ...
+  3. If S does not have a [[WeakSetData]] internal slot, throw a TypeError
+  exception.
+  ...
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.has.call(new Map(), {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.has.call(new Map(), {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/does-not-have-weaksetdata-internal-slot-object.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/does-not-have-weaksetdata-internal-slot-object.js
new file mode 100644
index 0000000000..b8ffc9af21
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/does-not-have-weaksetdata-internal-slot-object.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: >
+  Throws TypeError if context doesn't have a [[WeakSetData]] internal slot.
+info: |
+  WeakSet.prototype.has ( value )
+
+  ...
+  3. If S does not have a [[WeakSetData]] internal slot, throw a TypeError
+  exception.
+  ...
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.has.call({}, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.has.call({}, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/does-not-have-weaksetdata-internal-slot-set.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/does-not-have-weaksetdata-internal-slot-set.js
new file mode 100644
index 0000000000..9058742811
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/does-not-have-weaksetdata-internal-slot-set.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: >
+  Throws TypeError if context doesn't have a [[WeakSetData]] internal slot.
+info: |
+  WeakSet.prototype.has ( value )
+
+  ...
+  3. If S does not have a [[WeakSetData]] internal slot, throw a TypeError
+  exception.
+  ...
+features: [Set]
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.has.call(new Set(), {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.has.call(new Set(), {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/does-not-have-weaksetdata-internal-slot-weakset-prototype.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/does-not-have-weaksetdata-internal-slot-weakset-prototype.js
new file mode 100644
index 0000000000..85b34cc559
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/does-not-have-weaksetdata-internal-slot-weakset-prototype.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: >
+  Throws TypeError if context doesn't have a [[WeakSetData]] internal slot.
+info: |
+  WeakSet.prototype.has ( value )
+
+  ...
+  3. If S does not have a [[WeakSetData]] internal slot, throw a TypeError
+  exception.
+  ...
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.has.call(WeakSet.prototype, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.has.call(WeakSet.prototype, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/has.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/has.js
new file mode 100644
index 0000000000..9436ad778e
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/has.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: >
+  WeakSet.prototype.has property descriptor
+info: |
+  WeakSet.prototype.has ( value )
+
+  17 ECMAScript Standard Built-in Objects
+
+includes: [propertyHelper.js]
+---*/
+
+assert.sameValue(
+  typeof WeakSet.prototype.has,
+  'function',
+  'typeof WeakSet.prototype.has is "function"'
+);
+
+verifyNotEnumerable(WeakSet.prototype, 'has');
+verifyWritable(WeakSet.prototype, 'has');
+verifyConfigurable(WeakSet.prototype, 'has');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/length.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/length.js
new file mode 100644
index 0000000000..5e4176a5cc
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/length.js
@@ -0,0 +1,24 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: >
+  WeakSet.prototype.has.length value and writability.
+info: |
+  WeakSet.prototype.has ( value )
+
+  17 ECMAScript Standard Built-in Objects
+
+includes: [propertyHelper.js]
+---*/
+
+assert.sameValue(
+  WeakSet.prototype.has.length, 1,
+  'The value of WeakSet.prototype.has.length is 1'
+);
+
+verifyNotEnumerable(WeakSet.prototype.has, 'length');
+verifyNotWritable(WeakSet.prototype.has, 'length');
+verifyConfigurable(WeakSet.prototype.has, 'length');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/name.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/name.js
new file mode 100644
index 0000000000..6fca676585
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/name.js
@@ -0,0 +1,24 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: >
+  WeakSet.prototype.has.name value and writability.
+info: |
+  WeakSet.prototype.has ( value )
+
+  17 ECMAScript Standard Built-in Objects
+
+includes: [propertyHelper.js]
+---*/
+
+assert.sameValue(
+  WeakSet.prototype.has.name, 'has',
+  'The value of WeakSet.prototype.has.name is "has"'
+);
+
+verifyNotEnumerable(WeakSet.prototype.has, 'name');
+verifyNotWritable(WeakSet.prototype.has, 'name');
+verifyConfigurable(WeakSet.prototype.has, 'name');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/not-a-constructor.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/not-a-constructor.js
new file mode 100644
index 0000000000..b21d7cb36f
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/not-a-constructor.js
@@ -0,0 +1,35 @@
+// Copyright (C) 2020 Rick Waldron. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-ecmascript-standard-built-in-objects
+description: >
+  WeakSet.prototype.has does not implement [[Construct]], is not new-able
+info: |
+  ECMAScript Function Objects
+
+  Built-in function objects that are not identified as constructors do not
+  implement the [[Construct]] internal method unless otherwise specified in
+  the description of a particular function.
+
+  sec-evaluatenew
+
+  ...
+  7. If IsConstructor(constructor) is false, throw a TypeError exception.
+  ...
+includes: [isConstructor.js]
+features: [Reflect.construct, WeakSet, arrow-function]
+---*/
+
+assert.sameValue(
+  isConstructor(WeakSet.prototype.has),
+  false,
+  'isConstructor(WeakSet.prototype.has) must return false'
+);
+
+assert.throws(TypeError, () => {
+  let ws = new WeakSet(); new ws.has();
+}, '`let ws = new WeakSet(); new ws.has()` throws TypeError');
+
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/returns-false-when-object-value-not-present.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/returns-false-when-object-value-not-present.js
new file mode 100644
index 0000000000..61bb52e68b
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/returns-false-when-object-value-not-present.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: >
+  Return false when an Object value is not present in the WeakSet entries.
+info: |
+  WeakSet.prototype.has ( _value_ )
+  6. Return *false*.
+features: [WeakSet]
+---*/
+
+var foo = {};
+var bar = {};
+var s = new WeakSet();
+
+assert.sameValue(s.has(foo), false);
+
+s.add(foo);
+assert.sameValue(s.has(bar), false);
+
+s.delete(foo);
+assert.sameValue(s.has(foo), false);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/returns-false-when-symbol-value-not-present.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/returns-false-when-symbol-value-not-present.js
new file mode 100644
index 0000000000..f640fc25be
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/returns-false-when-symbol-value-not-present.js
@@ -0,0 +1,29 @@
+// |reftest| skip -- symbols-as-weakmap-keys is not supported
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: >
+  Return false when a Symbol value is not present in the WeakSet entries.
+info: |
+  WeakSet.prototype.has ( _value_ )
+  6. Return *false*.
+features: [Symbol, WeakSet, symbols-as-weakmap-keys]
+---*/
+
+var foo = Symbol('a description');
+var bar = Symbol('a description');
+var s = new WeakSet();
+
+assert.sameValue(s.has(foo), false, 'Set is initially empty of regular symbol');
+assert.sameValue(s.has(Symbol.hasInstance), false, 'Set is initially empty of well-known symbol');
+
+s.add(foo);
+assert.sameValue(s.has(bar), false, 'Symbols with the same description are not aliased to each other');
+
+s.delete(foo);
+assert.sameValue(s.has(foo), false, 'Set is again empty of regular symbol after deleting');
+s.delete(Symbol.hasInstance);
+assert.sameValue(s.has(Symbol.hasInstance), false, 'Set is again empty of well-known symbol after deleting');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/returns-false-when-value-cannot-be-held-weakly.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/returns-false-when-value-cannot-be-held-weakly.js
new file mode 100644
index 0000000000..257a3084e6
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/returns-false-when-value-cannot-be-held-weakly.js
@@ -0,0 +1,22 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: >
+  Returns false if value cannot be held weakly.
+info: |
+  WeakSet.prototype.has ( _value_ )
+  4. If CanBeHeldWeakly(_value_) is *false*, return *false*.
+features: [Symbol, WeakSet]
+---*/
+
+var s = new WeakSet();
+
+assert.sameValue(s.has(1), false);
+assert.sameValue(s.has(''), false);
+assert.sameValue(s.has(null), false);
+assert.sameValue(s.has(undefined), false);
+assert.sameValue(s.has(true), false);
+assert.sameValue(s.has(Symbol.for('registered symbol')), false, 'Registered symbol not allowed as value');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/returns-true-when-object-value-present.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/returns-true-when-object-value-present.js
new file mode 100644
index 0000000000..a573289c03
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/returns-true-when-object-value-present.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: >
+  Returns true when an Object value is present in the WeakSet entries list.
+info: |
+  WeakSet.prototype.has ( _value_ )
+  5. For each element _e_ of _entries_, do
+    a. If _e_ is not ~empty~ and SameValue(_e_, _value_) is *true*, return *true*.
+features: [WeakSet]
+---*/
+
+var foo = {};
+var s = new WeakSet();
+
+s.add(foo);
+assert.sameValue(s.has(foo), true);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/returns-true-when-symbol-value-present.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/returns-true-when-symbol-value-present.js
new file mode 100644
index 0000000000..3ff3428392
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/returns-true-when-symbol-value-present.js
@@ -0,0 +1,24 @@
+// |reftest| skip -- symbols-as-weakmap-keys is not supported
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: >
+  Returns true when a Symbol value is present in the WeakSet entries list.
+info: |
+  WeakSet.prototype.has ( _value_ )
+  5. For each element _e_ of _entries_, do
+    a. If _e_ is not ~empty~ and SameValue(_e_, _value_) is *true*, return *true*.
+features: [Symbol, WeakSet, symbols-as-weakmap-keys]
+---*/
+
+var foo = Symbol('a description');
+var s = new WeakSet();
+
+s.add(foo);
+assert.sameValue(s.has(foo), true, 'Regular symbol as value');
+
+s.add(Symbol.hasInstance);
+assert.sameValue(s.has(Symbol.hasInstance), true, 'Well-known symbol as value');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/shell.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/shell.js
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-boolean.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-boolean.js
new file mode 100644
index 0000000000..aa0ed435c9
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-boolean.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.has ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.has.call(false, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.has.call(false, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-null.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-null.js
new file mode 100644
index 0000000000..5d8c2507e0
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-null.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.has ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.has.call(null, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.has.call(null, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-number.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-number.js
new file mode 100644
index 0000000000..9ebc28ea00
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-number.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.has ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.has.call(0, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.has.call(0, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-string.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-string.js
new file mode 100644
index 0000000000..2be2567b3f
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-string.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.has ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.has.call('', {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.has.call('', {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-symbol.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-symbol.js
new file mode 100644
index 0000000000..24465cdc64
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-symbol.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.has ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+features: [Symbol]
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.has.call(Symbol(), {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.has.call(Symbol(), {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-undefined.js b/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-undefined.js
new file mode 100644
index 0000000000..33669f28b9
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/has/this-not-object-throw-undefined.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype.has
+description: Throws TypeError if `this` is not Object.
+info: |
+  WeakSet.prototype.has ( value )
+
+  1. Let S be the this value.
+  2. If Type(S) is not Object, throw a TypeError exception.
+
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet.prototype.has.call(undefined, {});
+});
+
+assert.throws(TypeError, function() {
+  var s = new WeakSet();
+  s.has.call(undefined, {});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/prototype-attributes.js b/js/src/tests/test262/built-ins/WeakSet/prototype/prototype-attributes.js
new file mode 100644
index 0000000000..682327d2a7
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/prototype-attributes.js
@@ -0,0 +1,14 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset.prototype
+description: >
+  WeakSet.prototype is not writable, not enumerable and not configurable.
+includes: [propertyHelper.js]
+---*/
+
+verifyNotEnumerable(WeakSet, 'prototype');
+verifyNotWritable(WeakSet, 'prototype');
+verifyNotConfigurable(WeakSet, 'prototype');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/prototype/shell.js b/js/src/tests/test262/built-ins/WeakSet/prototype/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/prototype/shell.js
diff --git a/js/src/tests/test262/built-ins/WeakSet/shell.js b/js/src/tests/test262/built-ins/WeakSet/shell.js
new file mode 100644
index 0000000000..eda1477282
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/shell.js
@@ -0,0 +1,24 @@
+// GENERATED, DO NOT EDIT
+// file: isConstructor.js
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: |
+    Test if a given function is a constructor function.
+defines: [isConstructor]
+features: [Reflect.construct]
+---*/
+
+function isConstructor(f) {
+    if (typeof f !== "function") {
+      throw new Test262Error("isConstructor invoked with a non-function value");
+    }
+
+    try {
+        Reflect.construct(function(){}, [], f);
+    } catch (e) {
+        return false;
+    }
+    return true;
+}
diff --git a/js/src/tests/test262/built-ins/WeakSet/undefined-newtarget.js b/js/src/tests/test262/built-ins/WeakSet/undefined-newtarget.js
new file mode 100644
index 0000000000..1839b33d0b
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/undefined-newtarget.js
@@ -0,0 +1,22 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset-iterable
+description: >
+  The WeakSet constructor is the %WeakSet% intrinsic object and the initial
+  value of the WeakSet property of the global object.
+info: |
+  23.4.1.1 WeakSet ( [ iterable ] )
+
+  1. If NewTarget is undefined, throw a TypeError exception.
+---*/
+
+assert.throws(TypeError, function() {
+  WeakSet();
+});
+
+assert.throws(TypeError, function() {
+  WeakSet([]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/WeakSet/weakset.js b/js/src/tests/test262/built-ins/WeakSet/weakset.js
new file mode 100644
index 0000000000..06e46a27e3
--- /dev/null
+++ b/js/src/tests/test262/built-ins/WeakSet/weakset.js
@@ -0,0 +1,16 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-weakset-iterable
+description: >
+  WeakSet ( [ iterable ] )
+
+  17 ECMAScript Standard Built-in Objects
+includes: [propertyHelper.js]
+---*/
+
+verifyNotEnumerable(this, 'WeakSet');
+verifyWritable(this, 'WeakSet');
+verifyConfigurable(this, 'WeakSet');
+
+reportCompare(0, 0);