[v20.x backport] esm: mark import attributes and JSON module as stable

common.gypi

@@ -36,7 +36,7 @@
 
     # Reset this number to 0 on major V8 upgrades.
     # Increment by one for each non-official patch applied to deps/v8.
-    'v8_embedder_string': '-node.23',
+    'v8_embedder_string': '-node.25',
 
     ##### V8 defaults for Node.js #####
 

deps/v8/src/common/message-template.h

@@ -113,6 +113,9 @@ namespace internal {
   T(IllegalInvocation, "Illegal invocation")                                   \
   T(ImmutablePrototypeSet,                                                     \
     "Immutable prototype object '%' cannot have their prototype set")          \
+  T(ImportAssertDeprecated,                                                    \
+    "'assert' is deprecated in import statements and support will be removed " \
+    "in %; use 'with' instead")                                                \
   T(ImportAssertionDuplicateKey, "Import assertion has duplicate key '%'")     \
   T(ImportCallNotNewExpression, "Cannot use new with import")                  \
   T(ImportOutsideModule, "Cannot use import statement outside a module")       \

deps/v8/src/execution/isolate.cc

@@ -5193,6 +5193,20 @@ MaybeHandle<FixedArray> Isolate::GetImportAssertionsFromArgument(
       // an error.
       return MaybeHandle<FixedArray>();
     }
+
+    if (V8_UNLIKELY(!import_assertions_object->IsUndefined())) {
+      MessageLocation* location = nullptr;
+      MessageLocation computed_location;
+      if (ComputeLocation(&computed_location)) {
+        location = &computed_location;
+      }
+      Handle<JSMessageObject> message = MessageHandler::MakeMessageObject(
+          this, MessageTemplate::kImportAssertDeprecated, location,
+          factory()->NewStringFromAsciiChecked("a future version"),
+          Handle<FixedArray>::null());
+      message->set_error_level(v8::Isolate::kMessageWarning);
+      MessageHandler::ReportMessage(this, location, message);
+    }
   }
 
   // If there is no 'with' or 'assert' option in the options bag, it's not an

deps/v8/src/parsing/parser.cc

@@ -1365,6 +1365,9 @@ ImportAssertions* Parser::ParseImportAssertClause() {
              !scanner()->HasLineTerminatorBeforeNext() &&
              CheckContextualKeyword(ast_value_factory()->assert_string())) {
     // 'assert' keyword consumed
+    info_->pending_error_handler()->ReportWarningAt(
+        position(), end_position(), MessageTemplate::kImportAssertDeprecated,
+        "a future version");
   } else {
     return import_assertions;
   }

deps/v8/test/message/fail/modules-import-assertions-fail-1.out

@@ -1 +1,2 @@
+*%(basename)s:9: 'assert' is deprecated in import statements and support will be removed in a future version; use 'with' instead
 undefined:0: Error: Invalid module type was asserted

deps/v8/test/message/fail/modules-import-assertions-fail-2.out

@@ -1,4 +1,5 @@
+*%(basename)s:9: 'assert' is deprecated in import statements and support will be removed in a future version; use 'with' instead
 undefined:1: SyntaxError: Unexpected token '/', "// Copyrig"... is not valid JSON
 // Copyright 2021 the V8 project authors. All rights reserved.
 ^
-SyntaxError: Unexpected token '/', "// Copyrig"... is not valid JSON
+SyntaxError: Unexpected token '/', "// Copyrig"... is not valid JSON

deps/v8/test/unittests/interpreter/bytecode_expectations/PrivateAccessorAccess.golden

@@ -83,7 +83,7 @@ bytecodes: [
   /*   48 E> */ B(DefineKeyedOwnProperty), R(this), R(0), U8(0), U8(0),
   /*   53 S> */ B(LdaImmutableCurrentContextSlot), U8(3),
   /*   58 E> */ B(GetKeyedProperty), R(this), U8(2),
-                B(Wide), B(LdaSmi), I16(311),
+                B(Wide), B(LdaSmi), I16(312),
                 B(Star2),
                 B(LdaConstant), U8(0),
                 B(Star3),
@@ -115,7 +115,7 @@ bytecodes: [
   /*   41 E> */ B(DefineKeyedOwnProperty), R(this), R(0), U8(0), U8(0),
   /*   46 S> */ B(LdaImmutableCurrentContextSlot), U8(3),
   /*   51 E> */ B(GetKeyedProperty), R(this), U8(2),
-                B(Wide), B(LdaSmi), I16(310),
+                B(Wide), B(LdaSmi), I16(311),
                 B(Star2),
                 B(LdaConstant), U8(0),
                 B(Star3),
@@ -149,7 +149,7 @@ bytecodes: [
                 B(Star2),
                 B(LdaImmutableCurrentContextSlot), U8(3),
   /*   58 E> */ B(GetKeyedProperty), R(this), U8(2),
-                B(Wide), B(LdaSmi), I16(311),
+                B(Wide), B(LdaSmi), I16(312),
                 B(Star3),
                 B(LdaConstant), U8(0),
                 B(Star4),
@@ -181,7 +181,7 @@ bytecodes: [
   /*   41 E> */ B(DefineKeyedOwnProperty), R(this), R(0), U8(0), U8(0),
   /*   46 S> */ B(LdaImmutableCurrentContextSlot), U8(3),
   /*   51 E> */ B(GetKeyedProperty), R(this), U8(2),
-                B(Wide), B(LdaSmi), I16(310),
+                B(Wide), B(LdaSmi), I16(311),
                 B(Star2),
                 B(LdaConstant), U8(0),
                 B(Star3),

deps/v8/test/unittests/interpreter/bytecode_expectations/PrivateMethodAccess.golden

@@ -58,7 +58,7 @@ bytecodes: [
                 B(Star2),
                 B(LdaImmutableCurrentContextSlot), U8(3),
   /*   54 E> */ B(GetKeyedProperty), R(this), U8(2),
-                B(Wide), B(LdaSmi), I16(309),
+                B(Wide), B(LdaSmi), I16(310),
                 B(Star3),
                 B(LdaConstant), U8(0),
                 B(Star4),
@@ -91,7 +91,7 @@ bytecodes: [
   /*   44 E> */ B(DefineKeyedOwnProperty), R(this), R(0), U8(0), U8(0),
   /*   49 S> */ B(LdaImmutableCurrentContextSlot), U8(3),
   /*   54 E> */ B(GetKeyedProperty), R(this), U8(2),
-                B(Wide), B(LdaSmi), I16(309),
+                B(Wide), B(LdaSmi), I16(311),
                 B(Star2),
                 B(LdaConstant), U8(0),
                 B(Star3),

deps/v8/test/unittests/interpreter/bytecode_expectations/StaticPrivateMethodAccess.golden

@@ -24,7 +24,7 @@ bytecodes: [
                 B(TestReferenceEqual), R(this),
                 B(Mov), R(this), R(1),
                 B(JumpIfTrue), U8(16),
-                B(Wide), B(LdaSmi), I16(303),
+                B(Wide), B(LdaSmi), I16(304),
                 B(Star2),
                 B(LdaConstant), U8(0),
                 B(Star3),
@@ -61,13 +61,13 @@ bytecodes: [
                 B(TestReferenceEqual), R(this),
                 B(Mov), R(this), R(0),
                 B(JumpIfTrue), U8(16),
-                B(Wide), B(LdaSmi), I16(303),
+                B(Wide), B(LdaSmi), I16(304),
                 B(Star2),
                 B(LdaConstant), U8(0),
                 B(Star3),
   /*   61 E> */ B(CallRuntime), U16(Runtime::kNewTypeError), R(2), U8(2),
                 B(Throw),
-                B(Wide), B(LdaSmi), I16(309),
+                B(Wide), B(LdaSmi), I16(310),
                 B(Star2),
                 B(LdaConstant), U8(1),
                 B(Star3),
@@ -99,13 +99,13 @@ bytecodes: [
                 B(TestReferenceEqual), R(this),
                 B(Mov), R(this), R(0),
                 B(JumpIfTrue), U8(16),
-                B(Wide), B(LdaSmi), I16(303),
+                B(Wide), B(LdaSmi), I16(304),
                 B(Star1),
                 B(LdaConstant), U8(0),
                 B(Star2),
   /*   61 E> */ B(CallRuntime), U16(Runtime::kNewTypeError), R(1), U8(2),
                 B(Throw),
-                B(Wide), B(LdaSmi), I16(309),
+                B(Wide), B(LdaSmi), I16(310),
                 B(Star1),
                 B(LdaConstant), U8(1),
                 B(Star2),
@@ -145,7 +145,7 @@ bytecodes: [
                 B(TestReferenceEqual), R(this),
                 B(Mov), R(this), R(0),
                 B(JumpIfTrue), U8(16),
-                B(Wide), B(LdaSmi), I16(303),
+                B(Wide), B(LdaSmi), I16(304),
                 B(Star2),
                 B(LdaConstant), U8(0),
                 B(Star3),
@@ -167,7 +167,7 @@ bytecodes: [
                 B(TestReferenceEqual), R(this),
                 B(Mov), R(this), R(0),
                 B(JumpIfTrue), U8(16),
-                B(Wide), B(LdaSmi), I16(303),
+                B(Wide), B(LdaSmi), I16(304),
                 B(Star3),
                 B(LdaConstant), U8(0),
                 B(Star4),
@@ -182,7 +182,7 @@ bytecodes: [
                 B(TestReferenceEqual), R(this),
                 B(Mov), R(this), R(0),
                 B(JumpIfTrue), U8(16),
-                B(Wide), B(LdaSmi), I16(303),
+                B(Wide), B(LdaSmi), I16(304),
                 B(Star2),
                 B(LdaConstant), U8(0),
                 B(Star3),
@@ -216,13 +216,13 @@ bytecodes: [
                 B(TestReferenceEqual), R(this),
                 B(Mov), R(this), R(0),
                 B(JumpIfTrue), U8(16),
-                B(Wide), B(LdaSmi), I16(303),
+                B(Wide), B(LdaSmi), I16(304),
                 B(Star1),
                 B(LdaConstant), U8(0),
                 B(Star2),
   /*   65 E> */ B(CallRuntime), U16(Runtime::kNewTypeError), R(1), U8(2),
                 B(Throw),
-                B(Wide), B(LdaSmi), I16(311),
+                B(Wide), B(LdaSmi), I16(312),
                 B(Star1),
                 B(LdaConstant), U8(1),
                 B(Star2),
@@ -253,13 +253,13 @@ bytecodes: [
                 B(TestReferenceEqual), R(this),
                 B(Mov), R(this), R(0),
                 B(JumpIfTrue), U8(16),
-                B(Wide), B(LdaSmi), I16(303),
+                B(Wide), B(LdaSmi), I16(304),
                 B(Star1),
                 B(LdaConstant), U8(0),
                 B(Star2),
   /*   58 E> */ B(CallRuntime), U16(Runtime::kNewTypeError), R(1), U8(2),
                 B(Throw),
-                B(Wide), B(LdaSmi), I16(310),
+                B(Wide), B(LdaSmi), I16(311),
                 B(Star1),
                 B(LdaConstant), U8(1),
                 B(Star2),
@@ -292,13 +292,13 @@ bytecodes: [
                 B(TestReferenceEqual), R(this),
                 B(Mov), R(this), R(0),
                 B(JumpIfTrue), U8(16),
-                B(Wide), B(LdaSmi), I16(303),
+                B(Wide), B(LdaSmi), I16(304),
                 B(Star2),
                 B(LdaConstant), U8(0),
                 B(Star3),
   /*   65 E> */ B(CallRuntime), U16(Runtime::kNewTypeError), R(2), U8(2),
                 B(Throw),
-                B(Wide), B(LdaSmi), I16(311),
+                B(Wide), B(LdaSmi), I16(312),
                 B(Star2),
                 B(LdaConstant), U8(1),
                 B(Star3),
@@ -327,7 +327,7 @@ bytecode array length: 19
 bytecodes: [
   /*   46 S> */ B(LdaImmutableCurrentContextSlot), U8(3),
   /*   51 E> */ B(GetKeyedProperty), R(this), U8(0),
-                B(Wide), B(LdaSmi), I16(310),
+                B(Wide), B(LdaSmi), I16(311),
                 B(Star1),
                 B(LdaConstant), U8(0),
                 B(Star2),

doc/api/esm.md

@@ -7,6 +7,9 @@
 <!-- YAML
 added: v8.5.0
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/55333
+    description: Import attributes are no longer experimental.
   - version: v20.10.0
     pr-url: https://github.com/nodejs/node/pull/50140
     description: Add experimental support for import attributes.
@@ -262,13 +265,9 @@
     description: Switch from Import Assertions to Import Attributes.
 -->
 
-> Stability: 1.1 - Active development
-
-> This feature was previously named "Import assertions", and using the `assert`
-> keyword instead of `with`. Any uses in code of the prior `assert` keyword
-> should be updated to use `with` instead.
+> Stability: 2 - Stable
 
-The [Import Attributes proposal][] adds an inline syntax for module import
+[Import attributes][Import Attributes MDN] are an inline syntax for module import
 statements to pass on more information alongside the module specifier.
 
 ```js
@@ -278,13 +277,14 @@
   await import('./bar.json', { with: { type: 'json' } });
 ```
 
-Node.js supports the following `type` values, for which the attribute is
-mandatory:
+Node.js only supports the `type` attribute, for which it supports the following values:
 
 | Attribute `type` | Needed for       |
 | ---------------- | ---------------- |
 | `'json'`         | [JSON modules][] |
 
+The `type: 'json'` attribute is mandatory when importing JSON modules.
+
 ## Built-in modules
 
 [Built-in modules][] provide named exports of their public API. A
@@ -591,7 +591,14 @@
 
 ## JSON modules
 
-> Stability: 1 - Experimental
+<!-- YAML
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/55333
+    description: JSON modules are no longer experimental.
+-->
+
+> Stability: 2 - Stable
 
 JSON files can be referenced by `import`:
 
@@ -1129,7 +1136,7 @@
 [Dynamic `import()`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/import
 [ES Module Integration Proposal for WebAssembly]: https://github.com/webassembly/esm-integration
 [Import Attributes]: #import-attributes
-[Import Attributes proposal]: https://github.com/tc39/proposal-import-attributes
+[Import Attributes MDN]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import/with
 [JSON modules]: #json-modules
 [Loading ECMAScript modules using `require()`]: modules.md#loading-ecmascript-modules-using-require
 [Module customization hooks]: module.md#customization-hooks

lib/internal/modules/esm/translators.js

@@ -450,7 +450,6 @@ translators.set('builtin', function builtinStrategy(url) {
 // Strategy for loading a JSON file
 const isWindows = process.platform === 'win32';
 translators.set('json', function jsonStrategy(url, source) {
-  emitExperimentalWarning('Importing JSON modules');
   assertBufferSource(source, true, 'load');
   debug(`Loading JSONModule ${url}`);
   const pathname = StringPrototypeStartsWith(url, 'file:') ?

test/es-module/test-esm-json.mjs

@@ -16,12 +16,12 @@ describe('ESM: importing JSON', () => {
     assert.strictEqual(secret.ofLife, 42);
   });
 
-  it('should print an experimental warning', async () => {
+  it('should not print an experimental warning', async () => {
     const { code, signal, stderr } = await spawnPromisified(execPath, [
       fixtures.path('/es-modules/json-modules.mjs'),
     ]);
 
-    assert.match(stderr, /ExperimentalWarning: Importing JSON modules/);
+    assert.strictEqual(stderr, '');
     assert.strictEqual(code, 0);
     assert.strictEqual(signal, null);
   });