Adding upstream version 124.0.1.upstream/124.0.1

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

39 files changed, 1210 insertions, 0 deletions

diff --git a/js/src/tests/test262/built-ins/Object/assign/ObjectOverride-sameproperty.js b/js/src/tests/test262/built-ins/Object/assign/ObjectOverride-sameproperty.js
new file mode 100644
index 0000000000..81f0f531ac
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/ObjectOverride-sameproperty.js
@@ -0,0 +1,22 @@
+// Copyright 2015 Microsoft Corporation. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+description: >
+  Object properties are assigned to target in ascending index order,
+  i.e. a later assignment to the same property overrides an earlier assignment.
+es6id:  19.1.2.1
+---*/
+
+var target = {
+  a: 1
+};
+var result = Object.assign(target, {
+  a: 2
+}, {
+  a: "c"
+});
+
+assert.sameValue(result.a, "c", "The value should be 'c'.");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/OnlyOneArgument.js b/js/src/tests/test262/built-ins/Object/assign/OnlyOneArgument.js
new file mode 100644
index 0000000000..3fe6d288f2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/OnlyOneArgument.js
@@ -0,0 +1,17 @@
+// Copyright 2015 Microsoft Corporation. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+description: >
+  test Object.Assign(target,...sources),only one argument was passed,
+  return ToObject(target)
+es6id:  19.1.2.1.3
+---*/
+
+var target = "a";
+var result = Object.assign(target);
+
+assert.sameValue(typeof result, "object");
+assert.sameValue(result.valueOf(), "a", "The value should be 'a'.");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/Override-notstringtarget.js b/js/src/tests/test262/built-ins/Object/assign/Override-notstringtarget.js
new file mode 100644
index 0000000000..2ade2ccbbd
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/Override-notstringtarget.js
@@ -0,0 +1,20 @@
+// Copyright 2015 Microsoft Corporation. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+description: >
+  Test override of Object.Assign(target,...sources),
+  Every string from sources will be wrapped to objects, and override from the first letter(result[0]) all the time
+es6id:  19.1.2.1
+---*/
+
+var target = 12;
+var result = Object.assign(target, "aaa", "bb2b", "1c");
+
+assert.sameValue(Object.getOwnPropertyNames(result).length, 4, "The length should be 4 in the final object.");
+assert.sameValue(result[0], "1", "The value should be {\"0\":\"1\"}.");
+assert.sameValue(result[1], "c", "The value should be {\"1\":\"c\"}.");
+assert.sameValue(result[2], "2", "The value should be {\"2\":\"2\"}.");
+assert.sameValue(result[3], "b", "The value should be {\"3\":\"b\"}.");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/Override.js b/js/src/tests/test262/built-ins/Object/assign/Override.js
new file mode 100644
index 0000000000..af125dcca7
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/Override.js
@@ -0,0 +1,37 @@
+// Copyright 2015 Microsoft Corporation. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+description: Test Object.Assign(target,...sources).
+esid: sec-object.assign
+---*/
+
+//"a" will be an property of the final object and the value should be 1
+var target = {
+  a: 1
+};
+/*
+"1a2c3" have own enumerable properties, so it Should be wrapped to objects;
+{b:6} is an object,should be assigned to final object.
+undefined and null should be ignored;
+125 is a number,it cannot has own enumerable properties;
+{a:"c"},{a:5} will override property a, the value should be 5.
+*/
+var result = Object.assign(target, "1a2c3", {
+  a: "c"
+}, undefined, {
+  b: 6
+}, null, 125, {
+  a: 5
+});
+
+assert.sameValue(Object.getOwnPropertyNames(result).length, 7, "The length should be 7 in the final object.");
+assert.sameValue(result.a, 5, "The value should be {a:5}.");
+assert.sameValue(result[0], "1", "The value should be {\"0\":\"1\"}.");
+assert.sameValue(result[1], "a", "The value should be {\"1\":\"a\"}.");
+assert.sameValue(result[2], "2", "The value should be {\"2\":\"2\"}.");
+assert.sameValue(result[3], "c", "The value should be {\"3\":\"c\"}.");
+assert.sameValue(result[4], "3", "The value should be {\"4\":\"3\"}.");
+assert.sameValue(result.b, 6, "The value should be {b:6}.");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/Source-Null-Undefined.js b/js/src/tests/test262/built-ins/Object/assign/Source-Null-Undefined.js
new file mode 100644
index 0000000000..b2f3a87750
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/Source-Null-Undefined.js
@@ -0,0 +1,14 @@
+// Copyright 2015 Microsoft Corporation. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+description: null and undefined source should be ignored,result should be original object.
+esid: sec-object.assign
+---*/
+
+var target = new Object();
+var result = Object.assign(target, undefined, null);
+
+assert.sameValue(result, target, 'The value of result is expected to equal the value of target');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/Source-Number-Boolen-Symbol.js b/js/src/tests/test262/built-ins/Object/assign/Source-Number-Boolen-Symbol.js
new file mode 100644
index 0000000000..60a851d5f9
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/Source-Number-Boolen-Symbol.js
@@ -0,0 +1,17 @@
+// Copyright 2015 Microsoft Corporation. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+description: >
+  Number,Boolean,Symbol cannot have own enumerable properties,
+  So cannot be Assigned.Here result should be original object.
+esid: sec-object.assign
+features: [Symbol]
+---*/
+
+var target = new Object();
+var result = Object.assign(target, 123, true, Symbol('foo'));
+
+assert.sameValue(result, target, 'The value of result is expected to equal the value of target');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/Source-String.js b/js/src/tests/test262/built-ins/Object/assign/Source-String.js
new file mode 100644
index 0000000000..d102c60f45
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/Source-String.js
@@ -0,0 +1,16 @@
+// Copyright 2015 Microsoft Corporation. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+description: Test Object.Assign(target,...sources), string have own enumerable properties, so it can be wrapped to objects.
+esid: sec-object.assign
+---*/
+
+var target = new Object();
+var result = Object.assign(target, "123");
+
+assert.sameValue(result[0], "1", 'The value of result[0] is expected to be "1"');
+assert.sameValue(result[1], "2", 'The value of result[1] is expected to be "2"');
+assert.sameValue(result[2], "3", 'The value of result[2] is expected to be "3"');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/Target-Boolean.js b/js/src/tests/test262/built-ins/Object/assign/Target-Boolean.js
new file mode 100644
index 0000000000..0f367bcf2d
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/Target-Boolean.js
@@ -0,0 +1,17 @@
+// Copyright 2015 Microsoft Corporation. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+description: >
+  Test the first argument(target) of Object.Assign(target,...sources),
+  if target is Boolean,the return value should be a new object whose value is target.
+es6id:  19.1.2.1.1
+---*/
+
+var result = Object.assign(true, {
+  a: 1
+});
+assert.sameValue(typeof result, "object", "Return value should be an object.");
+assert.sameValue(result.valueOf(), true, "Return value should be true.");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/Target-Null.js b/js/src/tests/test262/built-ins/Object/assign/Target-Null.js
new file mode 100644
index 0000000000..ffdd7fdabb
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/Target-Null.js
@@ -0,0 +1,17 @@
+// Copyright 2015 Microsoft Corporation. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+description: >
+  Test the first argument(target) of Object.Assign(target,...sources),
+  if target is null,Should Throw a TypeError exception.
+es6id:  19.1.2.1.1
+---*/
+
+assert.throws(TypeError, function() {
+  Object.assign(null, {
+    a: 1
+  });
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/Target-Number.js b/js/src/tests/test262/built-ins/Object/assign/Target-Number.js
new file mode 100644
index 0000000000..bdda581c38
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/Target-Number.js
@@ -0,0 +1,17 @@
+// Copyright 2015 Microsoft Corporation. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+description: >
+  Test the first argument(target) of Object.Assign(target,...sources),
+  if target is Number,the return value should be a new object whose value is target.
+es6id:  19.1.2.1.1
+---*/
+
+var result = Object.assign(1, {
+  a: 1
+});
+assert.sameValue(typeof result, "object", "Return value should be an object.");
+assert.sameValue(result.valueOf(), 1, "Return value should be 1.");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/Target-Object.js b/js/src/tests/test262/built-ins/Object/assign/Target-Object.js
new file mode 100644
index 0000000000..f8e8a68404
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/Target-Object.js
@@ -0,0 +1,21 @@
+// Copyright 2015 Microsoft Corporation. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+description: >
+  Test the first argument(target) of Object.Assign(target,...sources),
+  if target is Object,its properties will be the properties of new object.
+es6id:  19.1.2.1.1
+---*/
+
+var target = {
+  foo: 1
+};
+var result = Object.assign(target, {
+  a: 2
+});
+
+assert.sameValue(result.foo, 1, "The value should be {foo: 1}.");
+assert.sameValue(result.a, 2, "The value should be {a: 2}.");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/Target-String.js b/js/src/tests/test262/built-ins/Object/assign/Target-String.js
new file mode 100644
index 0000000000..aa16b4f2b3
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/Target-String.js
@@ -0,0 +1,17 @@
+// Copyright 2015 Microsoft Corporation. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+description: >
+  Test the first argument(target) of Object.Assign(target,...sources),
+  if target is String,the return value should be a new object whose value is target.
+es6id:  19.1.2.1.1
+---*/
+
+var result = Object.assign("test", {
+  a: 1
+});
+assert.sameValue(typeof result, "object", "Return value should be an object.");
+assert.sameValue(result.valueOf(), "test", "Return value should be 'test'.");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/Target-Symbol.js b/js/src/tests/test262/built-ins/Object/assign/Target-Symbol.js
new file mode 100644
index 0000000000..1430b4bd4f
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/Target-Symbol.js
@@ -0,0 +1,20 @@
+// Copyright 2015 Microsoft Corporation. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+description: >
+  Test the first argument(target) of Object.Assign(target,...sources),
+  if target is Symbol,the return value should be a new Symbol object whose [[SymbolData]] value is target.
+es6id:  19.1.2.1.1
+features: [Symbol]
+---*/
+
+var target = Symbol('foo');
+var result = Object.assign(target, {
+  a: 1
+});
+
+assert.sameValue(typeof result, "object", "Return value should be a symbol object.");
+assert.sameValue(result.toString(), "Symbol(foo)", "Return value should be 'Symbol(foo)'.");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/Target-Undefined.js b/js/src/tests/test262/built-ins/Object/assign/Target-Undefined.js
new file mode 100644
index 0000000000..882c5b516b
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/Target-Undefined.js
@@ -0,0 +1,17 @@
+// Copyright 2015 Microsoft Corporation. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+description: >
+  Test the first argument(target) of Object.Assign(target,...sources),
+  if target is Undefined,Should Throw a TypeError exception.
+es6id:  19.1.2.1.1
+---*/
+
+assert.throws(TypeError, function() {
+  Object.assign(undefined, {
+    a: 1
+  });
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/assign-descriptor.js b/js/src/tests/test262/built-ins/Object/assign/assign-descriptor.js
new file mode 100644
index 0000000000..5ee1c8216e
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/assign-descriptor.js
@@ -0,0 +1,14 @@
+// Copyright 2015 Microsoft Corporation. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+description: Testing descriptor property of Object.assign
+includes: [propertyHelper.js]
+es6id: 19.1.2.1
+---*/
+
+verifyWritable(Object, "assign");
+verifyNotEnumerable(Object, "assign");
+verifyConfigurable(Object, "assign");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/assign-length.js b/js/src/tests/test262/built-ins/Object/assign/assign-length.js
new file mode 100644
index 0000000000..bcfe2e2eda
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/assign-length.js
@@ -0,0 +1,26 @@
+// Copyright 2015 Microsoft Corporation. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+description: The length property of the assign method should be 2
+es6id:  19.1.2.1
+info: |
+    The length property of the assign method is 2.
+
+    ES6 Section 17:
+
+    Unless otherwise specified, the length property of a built-in Function
+    object has the attributes { [[Writable]]: false, [[Enumerable]]: false,
+    [[Configurable]]: true }.
+includes: [propertyHelper.js]
+---*/
+
+assert.sameValue(
+  Object.assign.length, 2, "The length property of the assign method should be 2."
+);
+
+verifyNotEnumerable(Object.assign, 'length');
+verifyNotWritable(Object.assign, 'length');
+verifyConfigurable(Object.assign, 'length');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/assignment-to-readonly-property-of-target-must-throw-a-typeerror-exception.js b/js/src/tests/test262/built-ins/Object/assign/assignment-to-readonly-property-of-target-must-throw-a-typeerror-exception.js
new file mode 100644
index 0000000000..d144ee5d49
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/assignment-to-readonly-property-of-target-must-throw-a-typeerror-exception.js
@@ -0,0 +1,31 @@
+// Copyright 2020 Rick Waldron. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+esid:  sec-object.assign
+description: >
+  Assignment to readonly property of target must throw a TypeError exception
+info: |
+  Let to be ? ToObject(target).
+  If only one argument was passed, return to.
+  For each element nextSource of sources, do
+    If nextSource is neither undefined nor null, then
+      Let from be ! ToObject(nextSource).
+      Let keys be ? from.[[OwnPropertyKeys]]().
+      For each element nextKey of keys, do
+        Let desc be ? from.[[GetOwnProperty]](nextKey).
+        If desc is not undefined and desc.[[Enumerable]] is true, then
+          Let propValue be ? Get(from, nextKey).
+          Perform ? Set(to, nextKey, propValue, true).
+
+  Set ( O, P, V, Throw ) sec-set-o-p-v-throw
+
+  Let success be ? O.[[Set]](P, V, O).
+  If success is false and Throw is true, throw a TypeError exception.
+---*/
+
+assert.throws(TypeError, () => {
+  Object.assign('a', [1]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/browser.js b/js/src/tests/test262/built-ins/Object/assign/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/browser.js
diff --git a/js/src/tests/test262/built-ins/Object/assign/invoked-as-ctor.js b/js/src/tests/test262/built-ins/Object/assign/invoked-as-ctor.js
new file mode 100644
index 0000000000..e60b4ff645
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/invoked-as-ctor.js
@@ -0,0 +1,18 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 19.1.2.1
+description: Invoked as a constructor
+info: |
+    ES6 Section 9.3:
+
+    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.
+---*/
+
+assert.throws(TypeError, function() {
+  new Object.assign({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/name.js b/js/src/tests/test262/built-ins/Object/assign/name.js
new file mode 100644
index 0000000000..bab32445c2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/name.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.
+/*---
+es6id: 19.1.2.1
+description: '`name` property'
+info: |
+    ES6 Section 17:
+
+    Every built-in Function object, including constructors, that is not
+    identified as an anonymous function has a name property whose value is a
+    String. Unless otherwise specified, this value is the name that is given to
+    the function in this specification.
+
+    [...]
+
+    Unless otherwise specified, the name property of a built-in Function
+    object, if it exists, has the attributes { [[Writable]]: false,
+    [[Enumerable]]: false, [[Configurable]]: true }.
+includes: [propertyHelper.js]
+---*/
+
+assert.sameValue(
+  Object.assign.name,
+  'assign',
+  'The value of `Object.assign.name` is `"assign"`'
+);
+
+verifyNotEnumerable(Object.assign, 'name');
+verifyNotWritable(Object.assign, 'name');
+verifyConfigurable(Object.assign, 'name');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/not-a-constructor.js b/js/src/tests/test262/built-ins/Object/assign/not-a-constructor.js
new file mode 100644
index 0000000000..3c66a4c64a
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/not-a-constructor.js
@@ -0,0 +1,31 @@
+// 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: >
+  Object.assign 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, arrow-function]
+---*/
+
+assert.sameValue(isConstructor(Object.assign), false, 'isConstructor(Object.assign) must return false');
+
+assert.throws(TypeError, () => {
+  new Object.assign({});
+}, '`new Object.assign({})` throws TypeError');
+
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/shell.js b/js/src/tests/test262/built-ins/Object/assign/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/shell.js
diff --git a/js/src/tests/test262/built-ins/Object/assign/source-get-attr-error.js b/js/src/tests/test262/built-ins/Object/assign/source-get-attr-error.js
new file mode 100644
index 0000000000..45dd48223d
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/source-get-attr-error.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.
+/*---
+es6id: 19.1.2.1
+description: Errors thrown during retrieval of source object attributes
+info: |
+    [...]
+    5. For each element nextSource of sources, in ascending index order,
+    [...]
+    c. Repeat for each element nextKey of keys in List order,
+       [...]
+       iii. if desc is not undefined and desc.[[Enumerable]] is true, then
+            1. Let propValue be Get(from, nextKey).
+            2. ReturnIfAbrupt(propValue).
+---*/
+
+var source = {
+  get attr() {
+    throw new Test262Error();
+  }
+};
+
+assert.throws(Test262Error, function() {
+  Object.assign({}, source);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/source-non-enum.js b/js/src/tests/test262/built-ins/Object/assign/source-non-enum.js
new file mode 100644
index 0000000000..e13857c627
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/source-non-enum.js
@@ -0,0 +1,30 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 19.1.2.1
+description: Does not assign non-enumerable source properties
+info: |
+    [...]
+    5. For each element nextSource of sources, in ascending index order,
+       c. Repeat for each element nextKey of keys in List order,
+          i. Let desc be from.[[GetOwnProperty]](nextKey).
+          ii. ReturnIfAbrupt(desc).
+          iii. if desc is not undefined and desc.[[Enumerable]] is true, then
+---*/
+
+var target = {};
+var source = Object.defineProperty({}, 'attr', {
+  value: 1,
+  enumerable: false
+});
+var result;
+
+result = Object.assign(target, source);
+
+assert(
+  !Object.prototype.hasOwnProperty.call(target, 'attr'),
+  "Non-enumerable property 'attr' does not get copied to target"
+);
+assert.sameValue(result, target);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/source-own-prop-desc-missing.js b/js/src/tests/test262/built-ins/Object/assign/source-own-prop-desc-missing.js
new file mode 100644
index 0000000000..54fc0dbe66
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/source-own-prop-desc-missing.js
@@ -0,0 +1,36 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 19.1.2.1
+description: Invoked with a source which does not have a descriptor for an own property
+info: |
+    [...]
+    5. For each element nextSource of sources, in ascending index order,
+       [...]
+       c. Repeat for each element nextKey of keys in List order,
+          i. Let desc be from.[[GetOwnProperty]](nextKey).
+          ii. ReturnIfAbrupt(desc).
+          iii. if desc is not undefined and desc.[[Enumerable]] is true, then
+features: [Proxy]
+---*/
+
+var callCount = 0;
+var target = {};
+var result;
+var source = new Proxy({}, {
+  ownKeys: function() {
+    callCount += 1;
+    return ['missing'];
+  }
+});
+
+result = Object.assign(target, source);
+
+assert.sameValue(callCount, 1, 'Proxy trap was invoked exactly once');
+assert(
+  !Object.prototype.hasOwnProperty.call(target, 'missing'),
+  'An own property was not created for a property without a property descriptor'
+);
+assert.sameValue(result, target);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/source-own-prop-error.js b/js/src/tests/test262/built-ins/Object/assign/source-own-prop-error.js
new file mode 100644
index 0000000000..0229bd3354
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/source-own-prop-error.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.
+/*---
+es6id: 19.1.2.1
+description: Invoked with a source whose own property descriptor cannot be retrieved
+info: |
+    [...]
+    5. For each element nextSource of sources, in ascending index order,
+       [...]
+       c. Repeat for each element nextKey of keys in List order,
+          i. Let desc be from.[[GetOwnProperty]](nextKey).
+          ii. ReturnIfAbrupt(desc).
+features: [Proxy]
+---*/
+
+var source = new Proxy({
+  attr: null
+}, {
+  getOwnPropertyDescriptor: function() {
+    throw new Test262Error();
+  }
+});
+
+assert.throws(Test262Error, function() {
+  Object.assign({}, source);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/source-own-prop-keys-error.js b/js/src/tests/test262/built-ins/Object/assign/source-own-prop-keys-error.js
new file mode 100644
index 0000000000..5cad1fbda1
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/source-own-prop-keys-error.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.
+/*---
+es6id: 19.1.2.1
+description: Invoked with a source whose own property keys cannot be retrieved
+info: |
+    [...]
+    5. For each element nextSource of sources, in ascending index order,
+       a. If nextSource is undefined or null, let keys be an empty List.
+       b. Else,
+          i. Let from be ToObject(nextSource).
+          ii. ReturnIfAbrupt(from).
+          iii. Let keys be from.[[OwnPropertyKeys]]().
+          iv. ReturnIfAbrupt(keys).
+features: [Proxy]
+---*/
+
+var source = new Proxy({}, {
+  ownKeys: function() {
+    throw new Test262Error();
+  }
+});
+
+assert.throws(Test262Error, function() {
+  Object.assign({}, source);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/strings-and-symbol-order-proxy.js b/js/src/tests/test262/built-ins/Object/assign/strings-and-symbol-order-proxy.js
new file mode 100644
index 0000000000..c4523a4df5
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/strings-and-symbol-order-proxy.js
@@ -0,0 +1,43 @@
+// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-object.assign
+description: >
+  Proxy keys are iterated in order they were provided by "ownKeys" trap.
+info: |
+  Object.assign ( target, ...sources )
+
+  [...]
+  4. For each element nextSource of sources, in ascending index order, do
+    a. If nextSource is neither undefined nor null, then
+      [...]
+      ii. Let keys be ? from.[[OwnPropertyKeys]]().
+      iii. For each element nextKey of keys in List order, do
+        1. Let desc be ? from.[[GetOwnProperty]](nextKey).
+
+  [[OwnPropertyKeys]] ( )
+
+  [...]
+  7. Let trapResultArray be ? Call(trap, handler, « target »).
+  8. Let trapResult be ? CreateListFromArrayLike(trapResultArray, « String, Symbol »).
+  [...]
+  23. Return trapResult.
+features: [Proxy, Symbol]
+includes: [compareArray.js]
+---*/
+
+var getOwnKeys = [];
+var ownKeysResult = [Symbol(), "foo", "0"];
+var proxy = new Proxy({}, {
+  getOwnPropertyDescriptor: function(_target, key) {
+    getOwnKeys.push(key);
+  },
+  ownKeys: function() {
+    return ownKeysResult;
+  },
+});
+
+Object.assign({}, proxy);
+assert.compareArray(getOwnKeys, ownKeysResult);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/strings-and-symbol-order.js b/js/src/tests/test262/built-ins/Object/assign/strings-and-symbol-order.js
new file mode 100644
index 0000000000..57cf13c377
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/strings-and-symbol-order.js
@@ -0,0 +1,63 @@
+// Copyright (C) 2018 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-object.assign
+description: >
+  Symbol-valued properties are copied after String-valued properties.
+info: |
+  19.1.2.1 Object.assign ( target, ...sources )
+
+  ...
+  4. For each element nextSource of sources, in ascending index order, do
+    a. ...
+    b. Else,
+      i. Let from be ! ToObject(nextSource).
+      ii. Let keys be ? from.[[OwnPropertyKeys]]().
+    c. For each element nextKey of keys in List order, do
+    ...
+  ...
+
+  9.1.11.1 OrdinaryOwnPropertyKeys ( O )
+
+  ...
+  3. For each own property key P of O that is a String but is not an integer index,
+     in ascending chronological order of property creation, do
+    a. Add P as the last element of keys.
+  4. For each own property key P of O that is a Symbol, in ascending chronological
+     order of property creation, do
+    a. Add P as the last element of keys.
+  ...
+
+includes: [compareArray.js]
+---*/
+
+var log = [];
+
+var sym1 = Symbol("x");
+var sym2 = Symbol("y");
+
+var source = {};
+
+Object.defineProperty(source, sym1, {
+    get: function(){ log.push("get sym(x)") },
+    enumerable: true, configurable: true,
+});
+Object.defineProperty(source, "a", {
+    get: function(){ log.push("get a") },
+    enumerable: true, configurable: true,
+});
+Object.defineProperty(source, sym2, {
+    get: function(){ log.push("get sym(y)") },
+    enumerable: true, configurable: true,
+});
+Object.defineProperty(source, "b", {
+    get: function(){ log.push("get b") },
+    enumerable: true, configurable: true,
+});
+
+var target = Object.assign({}, source);
+
+assert.compareArray(log, ["get a", "get b", "get sym(x)", "get sym(y)"]);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/target-is-frozen-accessor-property-set-succeeds.js b/js/src/tests/test262/built-ins/Object/assign/target-is-frozen-accessor-property-set-succeeds.js
new file mode 100644
index 0000000000..36d3065b26
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/target-is-frozen-accessor-property-set-succeeds.js
@@ -0,0 +1,65 @@
+// Copyright (C) 2021 Alexey Shvayka. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+esid: sec-object.assign
+description: >
+  [[Set]] to accessor property of frozen `target` succeeds.
+info: |
+  SetIntegrityLevel ( O, level )
+
+  [...]
+  3. Let status be ? O.[[PreventExtensions]]().
+  [...]
+  7. Else,
+    a. Assert: level is frozen.
+    b. For each element k of keys, do
+      i. Let currentDesc be ? O.[[GetOwnProperty]](k).
+      ii. If currentDesc is not undefined, then
+        1. If IsAccessorDescriptor(currentDesc) is true, then
+          a. Let desc be the PropertyDescriptor { [[Configurable]]: false }.
+        [...]
+        3. Perform ? DefinePropertyOrThrow(O, k, desc).
+  8. Return true.
+
+  Object.assign ( target, ...sources )
+
+  [...]
+  3. For each element nextSource of sources, do
+    a. If nextSource is neither undefined nor null, then
+      [...]
+      iii. For each element nextKey of keys, do
+        1. Let desc be ? from.[[GetOwnProperty]](nextKey).
+        2. If desc is not undefined and desc.[[Enumerable]] is true, then
+          [...]
+          b. Perform ? Set(to, nextKey, propValue, true).
+
+  OrdinarySetWithOwnDescriptor ( O, P, V, Receiver, ownDesc )
+
+  [...]
+  7. Perform ? Call(setter, Receiver, « V »).
+  8. Return true.
+features: [Symbol]
+---*/
+
+var value1 = 1;
+var target1 = {
+  set foo(val) { value1 = val; },
+};
+
+Object.freeze(target1);
+Object.assign(target1, { foo: 2 });
+assert.sameValue(value1, 2);
+
+
+var sym = Symbol();
+var value2 = 1;
+var target2 = Object.freeze({
+  set [sym](val) { value2 = val; },
+});
+
+Object.freeze(target2);
+Object.assign(target2, { [sym]: 2 });
+assert.sameValue(value2, 2);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/target-is-frozen-data-property-set-throws.js b/js/src/tests/test262/built-ins/Object/assign/target-is-frozen-data-property-set-throws.js
new file mode 100644
index 0000000000..943798ccc6
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/target-is-frozen-data-property-set-throws.js
@@ -0,0 +1,61 @@
+// Copyright (C) 2021 Alexey Shvayka. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+esid: sec-object.assign
+description: >
+  [[Set]] to data property of frozen `target` fails with TypeError.
+info: |
+  SetIntegrityLevel ( O, level )
+
+  [...]
+  3. Let status be ? O.[[PreventExtensions]]().
+  [...]
+  7. Else,
+    a. Assert: level is frozen.
+    b. For each element k of keys, do
+      i. Let currentDesc be ? O.[[GetOwnProperty]](k).
+      ii. If currentDesc is not undefined, then
+        1. If IsAccessorDescriptor(currentDesc) is true, then
+          [...]
+        2. Else,
+          a. Let desc be the PropertyDescriptor { [[Configurable]]: false, [[Writable]]: false }.
+        3. Perform ? DefinePropertyOrThrow(O, k, desc).
+  8. Return true.
+
+  Object.assign ( target, ...sources )
+
+  [...]
+  3. For each element nextSource of sources, do
+    a. If nextSource is neither undefined nor null, then
+      [...]
+      iii. For each element nextKey of keys, do
+        1. Let desc be ? from.[[GetOwnProperty]](nextKey).
+        2. If desc is not undefined and desc.[[Enumerable]] is true, then
+          [...]
+          b. Perform ? Set(to, nextKey, propValue, true).
+
+  OrdinarySetWithOwnDescriptor ( O, P, V, Receiver, ownDesc )
+
+  [...]
+  3. If IsDataDescriptor(ownDesc) is true, then
+    a. If ownDesc.[[Writable]] is false, return false.
+features: [Symbol, Reflect]
+---*/
+
+var sym = Symbol();
+var target1 = { [sym]: 1 };
+
+Object.freeze(target1);
+assert.throws(TypeError, function() {
+  Object.assign(target1, { [sym]: 1 });
+});
+
+
+var target2 = Object.freeze({ foo: 1 });
+
+assert.throws(TypeError, function() {
+  Object.assign(target2, { foo: 1 });
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/target-is-non-extensible-existing-accessor-property.js b/js/src/tests/test262/built-ins/Object/assign/target-is-non-extensible-existing-accessor-property.js
new file mode 100644
index 0000000000..f0d1d126fa
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/target-is-non-extensible-existing-accessor-property.js
@@ -0,0 +1,52 @@
+// Copyright (C) 2021 Alexey Shvayka. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+esid: sec-object.assign
+description: >
+  [[Set]] to existing accessor property of non-extensible `target` is successful.
+info: |
+  OrdinaryPreventExtensions ( O )
+
+  1. Set O.[[Extensible]] to false.
+
+  Object.assign ( target, ...sources )
+
+  [...]
+  3. For each element nextSource of sources, do
+    a. If nextSource is neither undefined nor null, then
+      [...]
+      iii. For each element nextKey of keys, do
+        1. Let desc be ? from.[[GetOwnProperty]](nextKey).
+        2. If desc is not undefined and desc.[[Enumerable]] is true, then
+          [...]
+          b. Perform ? Set(to, nextKey, propValue, true).
+
+  OrdinarySetWithOwnDescriptor ( O, P, V, Receiver, ownDesc )
+
+  [...]
+  7. Perform ? Call(setter, Receiver, « V »).
+  8. Return true.
+features: [Symbol]
+---*/
+
+var value1 = 1;
+var target1 = Object.preventExtensions({
+  set foo(val) { value1 = val; },
+});
+
+Object.assign(target1, { foo: 2 });
+assert.sameValue(value1, 2);
+
+
+var sym = Symbol();
+var value2 = 1;
+var target2 = {
+  set [sym](val) { value2 = val; },
+};
+
+Object.preventExtensions(target2);
+Object.assign(target2, { [sym]: 2 });
+assert.sameValue(value2, 2);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/target-is-non-extensible-existing-data-property.js b/js/src/tests/test262/built-ins/Object/assign/target-is-non-extensible-existing-data-property.js
new file mode 100644
index 0000000000..ebbf3a8e15
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/target-is-non-extensible-existing-data-property.js
@@ -0,0 +1,59 @@
+// Copyright (C) 2021 Alexey Shvayka. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+esid: sec-object.assign
+description: >
+  [[Set]] to existing data property of non-extensible `target` is successful.
+info: |
+  OrdinaryPreventExtensions ( O )
+
+  1. Set O.[[Extensible]] to false.
+
+  Object.assign ( target, ...sources )
+
+  [...]
+  3. For each element nextSource of sources, do
+    a. If nextSource is neither undefined nor null, then
+      [...]
+      iii. For each element nextKey of keys, do
+        1. Let desc be ? from.[[GetOwnProperty]](nextKey).
+        2. If desc is not undefined and desc.[[Enumerable]] is true, then
+          [...]
+          b. Perform ? Set(to, nextKey, propValue, true).
+
+  OrdinarySetWithOwnDescriptor ( O, P, V, Receiver, ownDesc )
+
+  [...]
+  3. If IsDataDescriptor(ownDesc) is true, then
+    [...]
+    c. Let existingDescriptor be ? Receiver.[[GetOwnProperty]](P).
+    d. If existingDescriptor is not undefined, then
+      [...]
+      iii. Let valueDesc be the PropertyDescriptor { [[Value]]: V }.
+      iv. Return ? Receiver.[[DefineOwnProperty]](P, valueDesc).
+
+  ValidateAndApplyPropertyDescriptor ( O, P, extensible, Desc, current )
+
+  [...]
+  9. If O is not undefined, then
+    a. For each field of Desc that is present, set the corresponding attribute
+       of the property named P of object O to the value of the field.
+  10. Return true.
+features: [Symbol]
+---*/
+
+var target1 = Object.preventExtensions({ foo: 1 });
+
+Object.assign(target1, { foo: 2 });
+assert.sameValue(target1.foo, 2);
+
+
+var sym = Symbol();
+var target2 = { [sym]: 1 };
+
+Object.preventExtensions(target2);
+Object.assign(target2, { [sym]: 2 });
+assert.sameValue(target2[sym], 2);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/target-is-non-extensible-property-creation-throws.js b/js/src/tests/test262/built-ins/Object/assign/target-is-non-extensible-property-creation-throws.js
new file mode 100644
index 0000000000..cbc5dda75e
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/target-is-non-extensible-property-creation-throws.js
@@ -0,0 +1,55 @@
+// Copyright (C) 2021 Alexey Shvayka. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+esid: sec-object.assign
+description: >
+  [[Set]] to non-existing property of non-extensible `target` fails with TypeError.
+info: |
+  Object.assign ( target, ...sources )
+
+  [...]
+  3. For each element nextSource of sources, do
+    a. If nextSource is neither undefined nor null, then
+      [...]
+      iii. For each element nextKey of keys, do
+        1. Let desc be ? from.[[GetOwnProperty]](nextKey).
+        2. If desc is not undefined and desc.[[Enumerable]] is true, then
+          [...]
+          b. Perform ? Set(to, nextKey, propValue, true).
+
+  OrdinarySetWithOwnDescriptor ( O, P, V, Receiver, ownDesc )
+
+  [...]
+  3. If IsDataDescriptor(ownDesc) is true, then
+    [...]
+    c. Let existingDescriptor be ? Receiver.[[GetOwnProperty]](P).
+    d. If existingDescriptor is not undefined, then
+      [...]
+    e. Else,
+      i. Assert: Receiver does not currently have a property P.
+      ii. Return ? CreateDataProperty(Receiver, P, V).
+
+  ValidateAndApplyPropertyDescriptor ( O, P, extensible, Desc, current )
+
+  [...]
+  2. If current is undefined, then
+    a. If extensible is false, return false.
+features: [Symbol]
+---*/
+
+var target1 = Object.preventExtensions({ foo: 1 });
+
+assert.throws(TypeError, function() {
+  Object.assign(target1, { get bar() {} });
+});
+
+
+var target2 = {};
+
+Object.preventExtensions(target2);
+assert.throws(TypeError, function() {
+  Object.assign(target2, { [Symbol()]: 1 });
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/target-is-sealed-existing-accessor-property.js b/js/src/tests/test262/built-ins/Object/assign/target-is-sealed-existing-accessor-property.js
new file mode 100644
index 0000000000..102511a969
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/target-is-sealed-existing-accessor-property.js
@@ -0,0 +1,57 @@
+// Copyright (C) 2021 Alexey Shvayka. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+esid: sec-object.assign
+description: >
+  [[Set]] to existing accessor property of sealed `target` is successful.
+info: |
+  SetIntegrityLevel ( O, level )
+
+  [...]
+  3. Let status be ? O.[[PreventExtensions]]().
+  [...]
+
+  OrdinaryPreventExtensions ( O )
+
+  1. Set O.[[Extensible]] to false.
+
+  Object.assign ( target, ...sources )
+
+  [...]
+  3. For each element nextSource of sources, do
+    a. If nextSource is neither undefined nor null, then
+      [...]
+      iii. For each element nextKey of keys, do
+        1. Let desc be ? from.[[GetOwnProperty]](nextKey).
+        2. If desc is not undefined and desc.[[Enumerable]] is true, then
+          [...]
+          b. Perform ? Set(to, nextKey, propValue, true).
+
+  OrdinarySetWithOwnDescriptor ( O, P, V, Receiver, ownDesc )
+
+  [...]
+  7. Perform ? Call(setter, Receiver, « V »).
+  8. Return true.
+---*/
+
+var value1 = 1;
+var target1 = Object.seal({
+  set foo(val) { value1 = val; },
+});
+
+Object.assign(target1, { foo: 2 });
+assert.sameValue(value1, 2);
+
+
+var sym = Symbol();
+var value2 = 1;
+var target2 = {
+  set [sym](val) { value2 = val; },
+};
+
+Object.seal(target2);
+Object.assign(target2, { [sym]: 2 });
+assert.sameValue(value2, 2);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/target-is-sealed-existing-data-property.js b/js/src/tests/test262/built-ins/Object/assign/target-is-sealed-existing-data-property.js
new file mode 100644
index 0000000000..31c05994e1
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/target-is-sealed-existing-data-property.js
@@ -0,0 +1,64 @@
+// Copyright (C) 2021 Alexey Shvayka. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+esid: sec-object.assign
+description: >
+  [[Set]] to existing data property of sealed `target` is successful.
+info: |
+  SetIntegrityLevel ( O, level )
+
+  [...]
+  3. Let status be ? O.[[PreventExtensions]]().
+  [...]
+
+  OrdinaryPreventExtensions ( O )
+
+  1. Set O.[[Extensible]] to false.
+
+  Object.assign ( target, ...sources )
+
+  [...]
+  3. For each element nextSource of sources, do
+    a. If nextSource is neither undefined nor null, then
+      [...]
+      iii. For each element nextKey of keys, do
+        1. Let desc be ? from.[[GetOwnProperty]](nextKey).
+        2. If desc is not undefined and desc.[[Enumerable]] is true, then
+          [...]
+          b. Perform ? Set(to, nextKey, propValue, true).
+
+  OrdinarySetWithOwnDescriptor ( O, P, V, Receiver, ownDesc )
+
+  [...]
+  3. If IsDataDescriptor(ownDesc) is true, then
+    [...]
+    c. Let existingDescriptor be ? Receiver.[[GetOwnProperty]](P).
+    d. If existingDescriptor is not undefined, then
+      [...]
+      iii. Let valueDesc be the PropertyDescriptor { [[Value]]: V }.
+      iv. Return ? Receiver.[[DefineOwnProperty]](P, valueDesc).
+
+  ValidateAndApplyPropertyDescriptor ( O, P, extensible, Desc, current )
+
+  [...]
+  9. If O is not undefined, then
+    a. For each field of Desc that is present, set the corresponding attribute
+       of the property named P of object O to the value of the field.
+  10. Return true.
+---*/
+
+var target1 = Object.seal({ foo: 1 });
+
+Object.assign(target1, { foo: 2 });
+assert.sameValue(target1.foo, 2);
+
+
+var sym = Symbol();
+var target2 = { [sym]: 1 };
+
+Object.seal(target2);
+Object.assign(target2, { [sym]: 2 });
+assert.sameValue(target2[sym], 2);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/target-is-sealed-property-creation-throws.js b/js/src/tests/test262/built-ins/Object/assign/target-is-sealed-property-creation-throws.js
new file mode 100644
index 0000000000..dd7ebae67b
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/target-is-sealed-property-creation-throws.js
@@ -0,0 +1,61 @@
+// Copyright (C) 2021 Alexey Shvayka. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+esid: sec-object.assign
+description: >
+  [[Set]] to non-existing property of sealed `target` fails with TypeError.
+info: |
+  SetIntegrityLevel ( O, level )
+
+  [...]
+  3. Let status be ? O.[[PreventExtensions]]().
+  [...]
+
+  Object.assign ( target, ...sources )
+
+  [...]
+  3. For each element nextSource of sources, do
+    a. If nextSource is neither undefined nor null, then
+      [...]
+      iii. For each element nextKey of keys, do
+        1. Let desc be ? from.[[GetOwnProperty]](nextKey).
+        2. If desc is not undefined and desc.[[Enumerable]] is true, then
+          [...]
+          b. Perform ? Set(to, nextKey, propValue, true).
+
+  OrdinarySetWithOwnDescriptor ( O, P, V, Receiver, ownDesc )
+
+  [...]
+  3. If IsDataDescriptor(ownDesc) is true, then
+    [...]
+    c. Let existingDescriptor be ? Receiver.[[GetOwnProperty]](P).
+    d. If existingDescriptor is not undefined, then
+      [...]
+    e. Else,
+      i. Assert: Receiver does not currently have a property P.
+      ii. Return ? CreateDataProperty(Receiver, P, V).
+
+  ValidateAndApplyPropertyDescriptor ( O, P, extensible, Desc, current )
+
+  [...]
+  2. If current is undefined, then
+    a. If extensible is false, return false.
+features: [Symbol, Reflect]
+---*/
+
+var target1 = Object.seal({ foo: 1 });
+
+assert.throws(TypeError, function() {
+  Object.assign(target1, { get bar() {} });
+});
+
+
+var target2 = {};
+
+Object.seal(target2);
+assert.throws(TypeError, function() {
+  Object.assign(target2, { [Symbol()]: 1 });
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/target-set-not-writable.js b/js/src/tests/test262/built-ins/Object/assign/target-set-not-writable.js
new file mode 100644
index 0000000000..930ddb8302
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/target-set-not-writable.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.
+/*---
+es6id: 19.1.2.1
+description: Errors thrown during definition of target object attributes
+info: |
+    [...]
+    5. For each element nextSource of sources, in ascending index order,
+    [...]
+    c. Repeat for each element nextKey of keys in List order,
+       [...]
+       iii. if desc is not undefined and desc.[[Enumerable]] is true, then
+            [...]
+            3. Let status be Set(to, nextKey, propValue, true).
+            4. ReturnIfAbrupt(status).
+---*/
+
+var target = {};
+Object.defineProperty(target, 'attr', {
+  writable: false
+});
+
+assert.throws(TypeError, function() {
+  Object.assign(target, {
+    attr: 1
+  });
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/Object/assign/target-set-user-error.js b/js/src/tests/test262/built-ins/Object/assign/target-set-user-error.js
new file mode 100644
index 0000000000..9a71116351
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/assign/target-set-user-error.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.
+/*---
+es6id: 19.1.2.1
+description: Errors thrown during definition of target object attributes
+info: |
+    [...]
+    5. For each element nextSource of sources, in ascending index order,
+    [...]
+    c. Repeat for each element nextKey of keys in List order,
+       [...]
+       iii. if desc is not undefined and desc.[[Enumerable]] is true, then
+            [...]
+            3. Let status be Set(to, nextKey, propValue, true).
+            4. ReturnIfAbrupt(status).
+---*/
+
+var target = {};
+Object.defineProperty(target, 'attr', {
+  set: function(_) {
+    throw new Test262Error();
+  }
+});
+
+assert.throws(Test262Error, function() {
+  Object.assign(target, {
+    attr: 1
+  });
+});
+
+reportCompare(0, 0);