diff --git a/deps/v8/include/v8-script.h b/deps/v8/include/v8-script.h
index 5644a3bb70c6b1..91b0a3d3e73378 100644
--- a/deps/v8/include/v8-script.h
+++ b/deps/v8/include/v8-script.h
@@ -128,10 +128,9 @@ class V8_EXPORT ModuleRequest : public Data {
    *
    * All assertions present in the module request will be supplied in this
    * list, regardless of whether they are supported by the host. Per
-   * https://tc39.es/proposal-import-assertions/#sec-hostgetsupportedimportassertions,
-   * hosts are expected to ignore assertions that they do not support (as
-   * opposed to, for example, triggering an error if an unsupported assertion is
-   * present).
+   * https://tc39.es/proposal-import-attributes/#sec-hostgetsupportedimportattributes,
+   * hosts are expected to throw for assertions that they do not support (as
+   * opposed to, for example, ignoring them).
    */
   Local<FixedArray> GetImportAssertions() const;
 
diff --git a/deps/v8/src/execution/isolate.cc b/deps/v8/src/execution/isolate.cc
index e5dba75764f6a9..d9bb966fe64af1 100644
--- a/deps/v8/src/execution/isolate.cc
+++ b/deps/v8/src/execution/isolate.cc
@@ -4726,7 +4726,7 @@ MaybeHandle<FixedArray> Isolate::GetImportAssertionsFromArgument(
 
   // The parser shouldn't have allowed the second argument to import() if
   // the flag wasn't enabled.
-  DCHECK(FLAG_harmony_import_assertions);
+  DCHECK(FLAG_harmony_import_assertions || FLAG_harmony_import_attributes);
 
   if (!import_assertions_argument->IsJSReceiver()) {
     this->Throw(
@@ -4736,18 +4736,35 @@ MaybeHandle<FixedArray> Isolate::GetImportAssertionsFromArgument(
 
   Handle<JSReceiver> import_assertions_argument_receiver =
       Handle<JSReceiver>::cast(import_assertions_argument);
-  Handle<Name> key = factory()->assert_string();
 
   Handle<Object> import_assertions_object;
-  if (!JSReceiver::GetProperty(this, import_assertions_argument_receiver, key)
-           .ToHandle(&import_assertions_object)) {
-    // This can happen if the property has a getter function that throws
-    // an error.
-    return MaybeHandle<FixedArray>();
+
+  if (FLAG_harmony_import_attributes) {
+    Handle<Name> with_key = factory()->with_string();
+    if (!JSReceiver::GetProperty(this, import_assertions_argument_receiver,
+                                 with_key)
+             .ToHandle(&import_assertions_object)) {
+      // This can happen if the property has a getter function that throws
+      // an error.
+      return MaybeHandle<FixedArray>();
+    }
   }
 
-  // If there is no 'assert' option in the options bag, it's not an error. Just
-  // do the import() as if no assertions were provided.
+  if (FLAG_harmony_import_assertions &&
+      (!FLAG_harmony_import_attributes ||
+       import_assertions_object->IsUndefined())) {
+    Handle<Name> assert_key = factory()->assert_string();
+    if (!JSReceiver::GetProperty(this, import_assertions_argument_receiver,
+                                 assert_key)
+             .ToHandle(&import_assertions_object)) {
+      // This can happen if the property has a getter function that throws
+      // an error.
+      return MaybeHandle<FixedArray>();
+    }
+  }
+
+  // If there is no 'with' or 'assert' option in the options bag, it's not an
+  // error. Just do the import() as if no assertions were provided.
   if (import_assertions_object->IsUndefined()) return import_assertions_array;
 
   if (!import_assertions_object->IsJSReceiver()) {
@@ -4769,6 +4786,8 @@ MaybeHandle<FixedArray> Isolate::GetImportAssertionsFromArgument(
     return MaybeHandle<FixedArray>();
   }
 
+  bool has_non_string_attribute = false;
+
   // The assertions will be passed to the host in the form: [key1,
   // value1, key2, value2, ...].
   constexpr size_t kAssertionEntrySizeForDynamicImport = 2;
@@ -4786,9 +4805,7 @@ MaybeHandle<FixedArray> Isolate::GetImportAssertionsFromArgument(
     }
 
     if (!assertion_value->IsString()) {
-      this->Throw(*factory()->NewTypeError(
-          MessageTemplate::kNonStringImportAssertionValue));
-      return MaybeHandle<FixedArray>();
+      has_non_string_attribute = true;
     }
 
     import_assertions_array->set((i * kAssertionEntrySizeForDynamicImport),
@@ -4797,6 +4814,12 @@ MaybeHandle<FixedArray> Isolate::GetImportAssertionsFromArgument(
                                  *assertion_value);
   }
 
+  if (has_non_string_attribute) {
+    this->Throw(*factory()->NewTypeError(
+        MessageTemplate::kNonStringImportAssertionValue));
+    return MaybeHandle<FixedArray>();
+  }
+
   return import_assertions_array;
 }
 
diff --git a/deps/v8/src/flags/flag-definitions.h b/deps/v8/src/flags/flag-definitions.h
index c101c5730c98f2..3e81ff98868841 100644
--- a/deps/v8/src/flags/flag-definitions.h
+++ b/deps/v8/src/flags/flag-definitions.h
@@ -300,6 +300,7 @@ DEFINE_BOOL(harmony_shipping, true, "enable all shipped harmony features")
 
 // Features that are still work in progress (behind individual flags).
 #define HARMONY_INPROGRESS_BASE(V)                                             \
+  V(harmony_import_attributes, "harmony import attributes")                    \
   V(harmony_weak_refs_with_cleanup_some,                                       \
     "harmony weak references with FinalizationRegistry.prototype.cleanupSome") \
   V(harmony_import_assertions, "harmony import assertions")                    \
diff --git a/deps/v8/src/init/bootstrapper.cc b/deps/v8/src/init/bootstrapper.cc
index d4c4122c22f4d7..ead61d6222907f 100644
--- a/deps/v8/src/init/bootstrapper.cc
+++ b/deps/v8/src/init/bootstrapper.cc
@@ -4482,6 +4482,7 @@ void Genesis::InitializeConsole(Handle<JSObject> extras_binding) {
   void Genesis::InitializeGlobal_##id() {}
 
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_import_assertions)
+EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_import_attributes)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_private_brand_checks)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_class_static_blocks)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_error_cause)
diff --git a/deps/v8/src/init/heap-symbols.h b/deps/v8/src/init/heap-symbols.h
index 8cd69613a678c3..cfff76beb4aaed 100644
--- a/deps/v8/src/init/heap-symbols.h
+++ b/deps/v8/src/init/heap-symbols.h
@@ -432,6 +432,7 @@
   V(_, week_string, "week")                                           \
   V(_, weeks_string, "weeks")                                         \
   V(_, weekOfYear_string, "weekOfYear")                               \
+  V(_, with_string, "with")                                           \
   V(_, word_string, "word")                                           \
   V(_, writable_string, "writable")                                   \
   V(_, yearMonthFromFields_string, "yearMonthFromFields")             \
diff --git a/deps/v8/src/parsing/parser-base.h b/deps/v8/src/parsing/parser-base.h
index cfa91e446f82e9..30dff440f6522b 100644
--- a/deps/v8/src/parsing/parser-base.h
+++ b/deps/v8/src/parsing/parser-base.h
@@ -3725,7 +3725,9 @@ ParserBase<Impl>::ParseImportExpressions() {
   AcceptINScope scope(this, true);
   ExpressionT specifier = ParseAssignmentExpressionCoverGrammar();
 
-  if (FLAG_harmony_import_assertions && Check(Token::COMMA)) {
+  if ((FLAG_harmony_import_assertions ||
+       FLAG_harmony_import_attributes) &&
+      Check(Token::COMMA)) {
     if (Check(Token::RPAREN)) {
       // A trailing comma allowed after the specifier.
       return factory()->NewImportCallExpression(specifier, pos);
diff --git a/deps/v8/src/parsing/parser.cc b/deps/v8/src/parsing/parser.cc
index 9789909456ee5e..92beebba5233ac 100644
--- a/deps/v8/src/parsing/parser.cc
+++ b/deps/v8/src/parsing/parser.cc
@@ -1344,27 +1344,34 @@ ZonePtrList<const Parser::NamedImport>* Parser::ParseNamedImports(int pos) {
 }
 
 ImportAssertions* Parser::ParseImportAssertClause() {
-  // AssertClause :
-  //    assert '{' '}'
-  //    assert '{' AssertEntries '}'
+  // WithClause :
+  //    with '{' '}'
+  //    with '{' WithEntries ','? '}'
 
-  // AssertEntries :
-  //    IdentifierName: AssertionKey
-  //    IdentifierName: AssertionKey , AssertEntries
+  // WithEntries :
+  //    LiteralPropertyName
+  //    LiteralPropertyName ':' StringLiteral , WithEntries
 
-  // AssertionKey :
-  //     IdentifierName
-  //     StringLiteral
+  // (DEPRECATED)
+  // AssertClause :
+  //    assert '{' '}'
+  //    assert '{' WithEntries ','? '}'
 
   auto import_assertions = zone()->New<ImportAssertions>(zone());
 
-  if (!FLAG_harmony_import_assertions) {
-    return import_assertions;
-  }
+  if (FLAG_harmony_import_attributes && Check(Token::WITH)) {
+    // 'with' keyword consumed
+  } else if (FLAG_harmony_import_assertions &&
+             !scanner()->HasLineTerminatorBeforeNext() &&
+             CheckContextualKeyword(ast_value_factory()->assert_string())) {
+    // The 'assert' contextual keyword is deprecated in favor of 'with', and we
+    // need to investigate feasibility of unshipping.
+    //
+    // TODO(v8:13856): Remove once decision is made to unship 'assert' or keep.
 
-  // Assert clause is optional, and cannot be preceded by a LineTerminator.
-  if (scanner()->HasLineTerminatorBeforeNext() ||
-      !CheckContextualKeyword(ast_value_factory()->assert_string())) {
+    // NOTE(Node.js): Commented out to avoid backporting this use counter to Node.js 18
+    // ++use_counts_[v8::Isolate::kImportAssertionDeprecatedSyntax];
+  } else {
     return import_assertions;
   }
 
@@ -1372,8 +1379,12 @@ ImportAssertions* Parser::ParseImportAssertClause() {
 
   while (peek() != Token::RBRACE) {
     const AstRawString* attribute_key = nullptr;
-    if (Check(Token::STRING)) {
+    if (Check(Token::STRING) || Check(Token::SMI)) {
       attribute_key = GetSymbol();
+    } else if (Check(Token::NUMBER)) {
+      attribute_key = GetNumberAsSymbol();
+    } else if (Check(Token::BIGINT)) {
+      attribute_key = GetBigIntAsSymbol();
     } else {
       attribute_key = ParsePropertyName();
     }
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-1.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-1.mjs
new file mode 100644
index 00000000000000..3cf6bac870b80f
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-1.mjs
@@ -0,0 +1,9 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-import-attributes
+
+import { life } from 'modules-skip-1.mjs' with { };
+
+assertEquals(42, life());
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-2.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-2.mjs
new file mode 100644
index 00000000000000..63f5859ca0f1d0
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-2.mjs
@@ -0,0 +1,9 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-import-attributes
+
+import json from 'modules-skip-1.json' with { type: 'json' };
+
+assertEquals(42, json.life);
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-3.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-3.mjs
new file mode 100644
index 00000000000000..34db1852367c19
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-3.mjs
@@ -0,0 +1,9 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-import-attributes
+
+import {life} from 'modules-skip-imports-json-1.mjs';
+
+assertEquals(42, life());
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-4.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-4.mjs
new file mode 100644
index 00000000000000..66bdc11c359ed4
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-4.mjs
@@ -0,0 +1,9 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-import-attributes
+
+import json from 'modules-skip-1.json' with { type: 'json', notARealAssertion: 'value'};
+
+assertEquals(42, json.life);
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-1.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-1.mjs
new file mode 100644
index 00000000000000..644fc96a6e2111
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-1.mjs
@@ -0,0 +1,12 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --harmony-import-attributes
+
+var life;
+import('modules-skip-1.mjs', { }).then(namespace => life = namespace.life());
+
+%PerformMicrotaskCheckpoint();
+
+assertEquals(42, life);
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-10.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-10.mjs
new file mode 100644
index 00000000000000..972fbed24bfff2
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-10.mjs
@@ -0,0 +1,19 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --harmony-import-attributes
+
+var result1;
+var result2;
+import('modules-skip-1.json', { get with() { throw 'bad \'with\' getter!'; } }).then(
+    () => assertUnreachable('Should have failed due to throwing getter'),
+    error => result1 = error);
+import('modules-skip-1.json', { with: { get assertionKey() { throw 'bad \'assertionKey\' getter!'; } } }).then(
+    () => assertUnreachable('Should have failed due to throwing getter'),
+    error => result2 = error);
+
+%PerformMicrotaskCheckpoint();
+
+assertEquals('bad \'with\' getter!', result1);
+assertEquals('bad \'assertionKey\' getter!', result2);
\ No newline at end of file
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-11.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-11.mjs
new file mode 100644
index 00000000000000..c39a5f9d4e2e06
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-11.mjs
@@ -0,0 +1,19 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --harmony-import-attributes --harmony-top-level-await
+
+var life1;
+var life2;
+import('modules-skip-1.json', { with: { type: 'json' } }).then(
+    namespace => life1 = namespace.default.life);
+
+// Try loading the same module a second time.
+import('modules-skip-1.json', { with: { type: 'json' } }).then(
+    namespace => life2 = namespace.default.life);
+
+%PerformMicrotaskCheckpoint();
+
+assertEquals(42, life1);
+assertEquals(42, life2);
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-12.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-12.mjs
new file mode 100644
index 00000000000000..1d8fb21a502237
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-12.mjs
@@ -0,0 +1,26 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --harmony-import-attributes
+
+let result1;
+let result2;
+
+let badAssertProxy1 = new Proxy({}, { ownKeys() { throw "bad ownKeys!"; } });
+import('./modules-skip-1.mjs', { with: badAssertProxy1 }).then(
+    () => assertUnreachable('Should have failed due to throwing ownKeys'),
+    error => result1 = error);
+
+let badAssertProxy2 = new Proxy(
+    {foo: "bar"},
+    { getOwnPropertyDescriptor() { throw "bad getOwnPropertyDescriptor!"; } });
+import('./modules-skip-1.mjs', { with: badAssertProxy2 }).then(
+    () => assertUnreachable(
+        'Should have failed due to throwing getOwnPropertyDescriptor'),
+    error => result2 = error);
+
+%PerformMicrotaskCheckpoint();
+
+assertEquals('bad ownKeys!', result1);
+assertEquals('bad getOwnPropertyDescriptor!', result2);
\ No newline at end of file
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-13.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-13.mjs
new file mode 100644
index 00000000000000..6e23c07c281db1
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-13.mjs
@@ -0,0 +1,26 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --harmony-import-attributes
+
+let getters = 0;
+let result;
+
+import('./modules-skip-1.mjs', { with: {
+    get attr1() {
+        getters++;
+        return {};
+    },
+    get attr2() {
+        getters++;
+        return {};
+    },
+} }).then(
+    () => assertUnreachable('Should have failed due to invalid attributes values'),
+    error => result = error);
+
+%PerformMicrotaskCheckpoint();
+
+assertEquals(2, getters);
+assertInstanceof(result, TypeError);
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-2.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-2.mjs
new file mode 100644
index 00000000000000..b8e59fb0bfe9c3
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-2.mjs
@@ -0,0 +1,13 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --harmony-import-attributes
+
+var life;
+import('modules-skip-1.mjs', { with: { } }).then(
+    namespace => life = namespace.life());
+
+%PerformMicrotaskCheckpoint();
+
+assertEquals(42, life);
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-3.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-3.mjs
new file mode 100644
index 00000000000000..da570eb2836edd
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-3.mjs
@@ -0,0 +1,13 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --harmony-import-attributes
+
+var life;
+import('modules-skip-1.json', { with: { type: 'json' } }).then(
+    namespace => life = namespace.default.life);
+
+%PerformMicrotaskCheckpoint();
+
+assertEquals(42, life);
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-4.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-4.mjs
new file mode 100644
index 00000000000000..fff6fe2bbef84c
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-4.mjs
@@ -0,0 +1,14 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --harmony-import-attributes
+
+var result;
+import('modules-skip-1.json', { with: { type: 'notARealType' } }).then(
+    () => assertUnreachable('Should have failed due to bad module type'),
+    error => result = error.message);
+
+%PerformMicrotaskCheckpoint();
+
+assertEquals('Invalid module type was asserted', result);
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-5.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-5.mjs
new file mode 100644
index 00000000000000..cdb1567c330764
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-5.mjs
@@ -0,0 +1,12 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --harmony-import-attributes
+
+var life;
+import('modules-skip-imports-json-1.mjs',).then(namespace => life = namespace.life());
+
+%PerformMicrotaskCheckpoint();
+
+assertEquals(42, life);
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-6.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-6.mjs
new file mode 100644
index 00000000000000..ad84e3edd5ffe1
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-6.mjs
@@ -0,0 +1,18 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --harmony-import-attributes
+
+var life;
+import('modules-skip-1.json', { with: { type: 'json', notARealAssertion: 'value' } }).then(
+    namespace => life = namespace.default.life);
+
+var life2;
+import('modules-skip-1.json', { with: { 0: 'value', type: 'json' } }).then(
+    namespace => life2 = namespace.default.life);
+
+%PerformMicrotaskCheckpoint();
+
+assertEquals(42, life);
+assertEquals(42, life2);
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-7.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-7.mjs
new file mode 100644
index 00000000000000..530d833cce5a4d
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-7.mjs
@@ -0,0 +1,63 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --harmony-import-attributes
+
+var result1;
+var result2;
+var result3;
+var result4;
+var result5;
+var result6;
+var result7;
+var result8;
+var result9;
+var result10;
+import('modules-skip-1.json', null).then(
+    () => assertUnreachable('Should have failed due to non-object parameter'),
+    error => result1 = error.message);
+import('modules-skip-1.json', 7).then(
+    () => assertUnreachable('Should have failed due to non-object parameter'),
+    error => result2 = error.message);
+import('modules-skip-1.json', 'string').then(
+        () => assertUnreachable('Should have failed due to non-object parameter'),
+        error => result3 = error.message);
+import('modules-skip-1.json', { with: null}).then(
+    () => assertUnreachable('Should have failed due to bad with object'),
+    error => result4 = error.message);
+import('modules-skip-1.json', { with: 7}).then(
+    () => assertUnreachable('Should have failed due to bad with object'),
+    error => result5 = error.message);
+import('modules-skip-1.json', { with: 'string'}).then(
+    () => assertUnreachable('Should have failed due to bad with object'),
+    error => result6 = error.message);
+import('modules-skip-1.json', { with: { a: null }}).then(
+    () => assertUnreachable('Should have failed due to bad with object'),
+    error => result7 = error.message);
+import('modules-skip-1.json', { with: { a: undefined }}).then(
+    () => assertUnreachable('Should have failed due to bad assertion value'),
+    error => result8 = error.message);
+import('modules-skip-1.json', { with: { a: 7 }}).then(
+    () => assertUnreachable('Should have failed due to bad assertion value'),
+    error => result9 = error.message);
+    import('modules-skip-1.json', { with: { a: { } }}).then(
+        () => assertUnreachable('Should have failed due to bad assertion value'),
+        error => result10 = error.message);
+
+%PerformMicrotaskCheckpoint();
+
+const argumentNotObjectError = 'The second argument to import() must be an object';
+const assertOptionNotObjectError = 'The \'assert\' option must be an object';
+const assertionValueNotStringError = 'Import assertion value must be a string';
+
+assertEquals(argumentNotObjectError, result1);
+assertEquals(argumentNotObjectError, result2);
+assertEquals(argumentNotObjectError, result3);
+assertEquals(assertOptionNotObjectError, result4);
+assertEquals(assertOptionNotObjectError, result5);
+assertEquals(assertOptionNotObjectError, result6);
+assertEquals(assertionValueNotStringError, result7);
+assertEquals(assertionValueNotStringError, result8);
+assertEquals(assertionValueNotStringError, result9);
+assertEquals(assertionValueNotStringError, result10);
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-8.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-8.mjs
new file mode 100644
index 00000000000000..74a4504e253d6a
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-8.mjs
@@ -0,0 +1,13 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --harmony-import-attributes
+
+var life;
+import('modules-skip-1.mjs', undefined).then(
+    namespace => life = namespace.life());
+
+%PerformMicrotaskCheckpoint();
+
+assertEquals(42, life);
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-9.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-9.mjs
new file mode 100644
index 00000000000000..1b56c70df61682
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-9.mjs
@@ -0,0 +1,13 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --harmony-import-attributes
+
+var life;
+import('modules-skip-1.mjs', { with: undefined }).then(
+    namespace => life = namespace.life());
+
+%PerformMicrotaskCheckpoint();
+
+assertEquals(42, life);
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-assertions-fallback-1.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-assertions-fallback-1.mjs
new file mode 100644
index 00000000000000..3faaf0dccea1c9
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-assertions-fallback-1.mjs
@@ -0,0 +1,15 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --harmony-import-attributes --harmony-import-assertions
+
+var life;
+import('modules-skip-1.mjs', {
+    with: {},
+    get assert() { throw 'Should not read assert'; }
+}).then(namespace => life = namespace.life());
+
+%PerformMicrotaskCheckpoint();
+
+assertEquals(42, life);
diff --git a/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-assertions-fallback-2.mjs b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-assertions-fallback-2.mjs
new file mode 100644
index 00000000000000..4c83d2fbd716cc
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/modules-import-attributes-dynamic-assertions-fallback-2.mjs
@@ -0,0 +1,15 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --harmony-import-attributes --harmony-import-assertions
+
+var life;
+import('modules-skip-1.json', {
+    with: undefined,
+    assert: { type: 'json' }
+}).then(namespace => life = namespace.default.life);
+
+%PerformMicrotaskCheckpoint();
+
+assertEquals(42, life);