chore: release LWC v9

commitlint.config.js

@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: MIT
  * For full license text, see the LICENSE file in the repo root or https://opensource.org/licenses/MIT
  */
-module.exports = {
+export default {
     rules: {
         'body-leading-blank': [1, 'always'],
         'footer-leading-blank': [1, 'always'],

eslint.config.mjs

@@ -189,7 +189,7 @@ export default tseslint.config(
         },
     },
     {
-        files: ['**/*.js', '**/*.mjs', '**/*.cjs'],
+        files: ['**/*.js', '**/*.mjs'],
         ...tseslint.configs.disableTypeChecked,
     },
 

package.json

@@ -7,6 +7,7 @@
         "type": "git",
         "url": "https://github.com/salesforce/lwc.git"
     },
+    "type": "module",
     "scripts": {
         "prepare": "husky && yarn build",
         "lint": "eslint . --cache",
@@ -25,7 +26,7 @@
         "test:ci": "vitest run --coverage",
         "test:wtr": "nx test @lwc/integration-wtr",
         "test:hydration": "nx test:hydration @lwc/integration-wtr",
-        "test:integration": "nx sauce @lwc/integration-wdio",
+        "test:wdio": "nx sauce @lwc/integration-wdio",
         "test:performance": "nx test @lwc/perf-benchmarks",
         "test:performance:best": "nx test:best @lwc/perf-benchmarks",
         "test:performance:best:ci": "nx test:best:ci @lwc/perf-benchmarks",
@@ -72,7 +73,7 @@
         "rollup": "^4.53.3",
         "terser": "^5.44.1",
         "tslib": "^2.8.1",
-        "typescript": "5.8.2",
+        "typescript": "6.0.0-dev.20251217",
         "typescript-eslint": "8.50.0",
         "vitest": "4.0.16"
     },
@@ -87,9 +88,6 @@
         "packages/lwc",
         "playground"
     ],
-    "engines": {
-        "node": ">=10"
-    },
     "volta": {
         "node": "24.11.1",
         "yarn": "1.22.22"

packages/@lwc/aria-reflection/package.json

@@ -23,13 +23,17 @@
         "url": "https://github.com/salesforce/lwc/issues"
     },
     "license": "MIT",
+    "type": "module",
     "publishConfig": {
         "access": "public"
     },
+    "engines": {
+        "node": ">=16.6.0"
+    },
     "volta": {
         "extends": "../../../package.json"
     },
-    "main": "dist/index.cjs.js",
+    "main": "dist/index.js",
     "module": "dist/index.js",
     "types": "dist/index.d.ts",
     "files": [

packages/@lwc/babel-plugin-component/README.md

@@ -21,8 +21,8 @@ This babel plugin does the following transform:
 ## Usage
 
 ```js
-const babel = require('@babel/core');
-const lwcPlugin = require('@lwc/babel-plugin-component');
+import babel from '@babel/core';
+import lwcPlugin from '@lwc/babel-plugin-component';
 
 const source = `
 import { LightningElement } from 'lwc';

packages/@lwc/babel-plugin-component/package.json

@@ -19,13 +19,17 @@
         "url": "https://github.com/salesforce/lwc/issues"
     },
     "license": "MIT",
+    "type": "module",
     "publishConfig": {
         "access": "public"
     },
+    "engines": {
+        "node": ">=16.6.0"
+    },
     "volta": {
         "extends": "../../../package.json"
     },
-    "main": "dist/index.cjs.js",
+    "main": "dist/index.js",
     "module": "dist/index.js",
     "types": "dist/index.d.ts",
     "files": [

packages/@lwc/babel-plugin-component/src/__tests__/index.spec.ts

@@ -81,7 +81,7 @@ function transform(source: string, opts = {}) {
 describe('fixtures', () => {
     testFixtureDir<TestConfig>(
         {
-            root: path.resolve(__dirname, 'fixtures'),
+            root: path.resolve(import.meta.dirname, 'fixtures'),
             pattern: '**/actual.js',
             ssrVersion: 2,
         },

packages/@lwc/babel-plugin-component/src/component.ts

@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: MIT
  * For full license text, see the LICENSE file in the repo root or https://opensource.org/licenses/MIT
  */
-import { basename, extname } from 'path';
+import { basename, extname } from 'node:path';
 import { addDefault, addNamed } from '@babel/helper-module-imports';
 import { generateCustomElementTagName, getAPIVersionFromNumber } from '@lwc/shared';
 import {

packages/@lwc/compiler/README.md

@@ -42,7 +42,7 @@ const { code } = transformSync(source, filename, options);
     - `name` (type: `string`, required) - name of the component, e.g. `foo` in `x/foo`.
     - `namespace` (type: `string`, required) - namespace of the component, e.g. `x` in `x/foo`.
     - `stylesheetConfig` (type: `object`, default: `{}`) - Deprecated. Ignored by compiler.
-    - `experimentalDynamicComponent` (type: `DynamicImportConfig`, default: `null`) - The configuration to pass to `@lwc/compiler`.
+    - `dynamicImports` (type: `DynamicImportConfig`, default: `null`) - The configuration to pass to `@lwc/compiler`.
     - `experimentalDynamicDirective` (type: `boolean`, default: `false`) - The configuration to pass to `@lwc/template-compiler` to enable deprecated dynamic components.
     - `enableDynamicComponents` (type: `boolean`, default: `false`) - The configuration to pass to `@lwc/template-compiler` to enable dynamic components.
     - `outputConfig` (type: `object`, optional) - see below:

packages/@lwc/compiler/package.json

@@ -19,13 +19,17 @@
         "url": "https://github.com/salesforce/lwc/issues"
     },
     "license": "MIT",
+    "type": "module",
     "publishConfig": {
         "access": "public"
     },
+    "engines": {
+        "node": ">=16.6.0"
+    },
     "volta": {
         "extends": "../../../package.json"
     },
-    "main": "dist/index.cjs.js",
+    "main": "dist/index.js",
     "module": "dist/index.js",
     "types": "dist/index.d.ts",
     "files": [

packages/@lwc/compiler/src/options.ts

@@ -102,9 +102,8 @@ export interface TransformOptions {
     namespace: string;
     /** @deprecated Ignored by compiler. */
     stylesheetConfig?: StylesheetConfig;
-    // TODO [#5031]: Unify dynamicImports and experimentalDynamicComponent options
     /** Config applied in usage of dynamic import statements in javascript */
-    experimentalDynamicComponent?: DynamicImportConfig;
+    dynamicImports?: DynamicImportConfig;
     // TODO [#3331]: deprecate and remove lwc:dynamic
     /** Flag to enable usage of dynamic component(lwc:dynamic) directive in HTML template */
     experimentalDynamicDirective?: boolean;
@@ -163,7 +162,7 @@ type OptionalTransformKeys =
     | 'enableDynamicComponents'
     | 'enableSyntheticElementInternals'
     | 'experimentalDynamicDirective'
-    | 'experimentalDynamicComponent'
+    | 'dynamicImports'
     | 'componentFeatureFlagModulePath'
     | 'instrumentation';
 
@@ -246,9 +245,9 @@ function normalizeOptions(options: TransformOptions): NormalizedTransformOptions
         },
     };
 
-    const experimentalDynamicComponent: Required<DynamicImportConfig> = {
+    const dynamicImports: Required<DynamicImportConfig> = {
         ...DEFAULT_DYNAMIC_IMPORT_CONFIG,
-        ...options.experimentalDynamicComponent,
+        ...options.dynamicImports,
     };
 
     const apiVersion = getAPIVersionFromNumber(options.apiVersion);
@@ -258,7 +257,7 @@ function normalizeOptions(options: TransformOptions): NormalizedTransformOptions
         ...options,
         stylesheetConfig,
         outputConfig,
-        experimentalDynamicComponent,
+        dynamicImports,
         apiVersion,
     };
 }

packages/@lwc/compiler/src/transformers/__tests__/transform-javascript.spec.ts

@@ -131,7 +131,7 @@ describe('instrumentation', () => {
         `;
         await transform(actual, 'foo.js', {
             ...BASE_TRANSFORM_OPTIONS,
-            experimentalDynamicComponent: {
+            dynamicImports: {
                 loader: '@custom/loader',
                 strictSpecifier: true,
             },

packages/@lwc/compiler/src/transformers/javascript.ts

@@ -41,8 +41,7 @@ export default function scriptTransform(
     const {
         isExplicitImport,
         enableSyntheticElementInternals,
-        // TODO [#5031]: Unify dynamicImports and experimentalDynamicComponent options
-        experimentalDynamicComponent: dynamicImports,
+        dynamicImports,
         outputConfig: { sourcemap },
         enableLightningWebSecurityTransforms,
         namespace,

packages/@lwc/compiler/src/transformers/template.ts

@@ -33,7 +33,7 @@ export default function templateTransform(
     options: NormalizedTransformOptions
 ): TransformResult {
     const {
-        experimentalDynamicComponent,
+        dynamicImports,
         // TODO [#3370]: remove experimental template expression flag
         experimentalComplexExpressions,
         preserveHtmlComments,
@@ -49,8 +49,7 @@ export default function templateTransform(
         disableSyntheticShadowSupport,
         experimentalErrorRecoveryMode,
     } = options;
-    const experimentalDynamicDirective =
-        deprecatedDynamicDirective ?? Boolean(experimentalDynamicComponent);
+    const experimentalDynamicDirective = deprecatedDynamicDirective ?? Boolean(dynamicImports);
 
     let result;
     try {

packages/@lwc/compiler/src/transformers/transformer.ts

@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: MIT
  * For full license text, see the LICENSE file in the repo root or https://opensource.org/licenses/MIT
  */
-import * as path from 'path';
+import * as path from 'node:path';
 
 import { isString } from '@lwc/shared';
 import { TransformerErrors, generateCompilerError, invariant } from '@lwc/errors';

packages/@lwc/engine-core/package.json

@@ -19,13 +19,17 @@
         "url": "https://github.com/salesforce/lwc/issues"
     },
     "license": "MIT",
+    "type": "module",
     "publishConfig": {
         "access": "public"
     },
+    "engines": {
+        "node": ">=16.6.0"
+    },
     "volta": {
         "extends": "../../../package.json"
     },
-    "main": "dist/index.cjs.js",
+    "main": "dist/index.js",
     "module": "dist/index.js",
     "types": "dist/index.d.ts",
     "files": [

packages/@lwc/engine-core/src/framework/decorators/register.ts

@@ -39,7 +39,7 @@ export const enum PropType {
 
 interface PropCompilerDef {
     config: PropType; // 0 m
-    type: string; // TODO [#1301]: make this an enum
+    type: string;
 }
 interface WireCompilerDef {
     method?: number;
@@ -75,7 +75,7 @@ function validateObservedField(
         const type = getClassDescriptorType(descriptor);
         const message = `Invalid observed ${fieldName} field. Found a duplicate ${type} with the same name.`;
 
-        // TODO [#3408]: this should throw, not log
+        // TODO [#4450]: this should throw, not log
         logError(message);
     }
 }
@@ -88,7 +88,7 @@ function validateFieldDecoratedWithTrack(
     assertNotProd(); // this method should never leak to prod
     if (!isUndefined(descriptor)) {
         const type = getClassDescriptorType(descriptor);
-        // TODO [#3408]: this should throw, not log
+        // TODO [#4450]: this should throw, not log
         logError(
             `Invalid @track ${fieldName} field. Found a duplicate ${type} with the same name.`
         );
@@ -103,7 +103,7 @@ function validateFieldDecoratedWithWire(
     assertNotProd(); // this method should never leak to prod
     if (!isUndefined(descriptor)) {
         const type = getClassDescriptorType(descriptor);
-        // TODO [#3408]: this should throw, not log
+        // TODO [#4450]: this should throw, not log
         logError(`Invalid @wire ${fieldName} field. Found a duplicate ${type} with the same name.`);
     }
 }
@@ -115,7 +115,7 @@ function validateMethodDecoratedWithWire(
 ) {
     assertNotProd(); // this method should never leak to prod
     if (isUndefined(descriptor) || !isFunction(descriptor.value) || isFalse(descriptor.writable)) {
-        // TODO [#3441]: This line of code does not seem possible to reach.
+        // TODO [#4450]: This line of code does not seem possible to reach.
         logError(
             `Invalid @wire ${methodName} field. The field should have a valid writable descriptor.`
         );
@@ -132,7 +132,7 @@ function validateFieldDecoratedWithApi(
         const type = getClassDescriptorType(descriptor);
         const message = `Invalid @api ${fieldName} field. Found a duplicate ${type} with the same name.`;
 
-        // TODO [#3408]: this should throw, not log
+        // TODO [#4450]: this should throw, not log
         logError(message);
     }
 }
@@ -145,7 +145,7 @@ function validateAccessorDecoratedWithApi(
     assertNotProd(); // this method should never leak to prod
     if (isFunction(descriptor.set)) {
         if (!isFunction(descriptor.get)) {
-            // TODO [#3441]: This line of code does not seem possible to reach.
+            // TODO [#4450]: This line of code does not seem possible to reach.
             logError(
                 `Missing getter for property ${fieldName} decorated with @api in ${Ctor}. You cannot have a setter without the corresponding getter.`
             );
@@ -246,7 +246,7 @@ export function registerDecorators(
             if (method === 1) {
                 if (process.env.NODE_ENV !== 'production') {
                     if (!adapter) {
-                        // TODO [#3408]: this should throw, not log
+                        // TODO [#4450]: this should throw, not log
                         logError(
                             `@wire on method "${fieldOrMethodName}": adapter id must be truthy.`
                         );
@@ -261,7 +261,7 @@ export function registerDecorators(
             } else {
                 if (process.env.NODE_ENV !== 'production') {
                     if (!adapter) {
-                        // TODO [#3408]: this should throw, not log
+                        // TODO [#4450]: this should throw, not log
                         logError(
                             `@wire on field "${fieldOrMethodName}": adapter id must be truthy.`
                         );

packages/@lwc/engine-core/src/framework/decorators/wire.ts

@@ -59,10 +59,10 @@ interface WireDecorator<Value, Class> {
  * }
  */
 export default function wire<
-    ReactiveConfig extends ConfigValue = ConfigValue,
-    Value = any,
-    Context extends ContextValue = ContextValue,
-    Class = LightningElement,
+    const ReactiveConfig extends ConfigValue = ConfigValue,
+    const Value = any,
+    const Context extends ContextValue = ContextValue,
+    const Class = LightningElement,
 >(
     // eslint-disable-next-line @typescript-eslint/no-unused-vars
     adapter:

packages/@lwc/engine-core/src/framework/rendering.ts

@@ -870,7 +870,6 @@ function createKeyToOldIdx(
 ): Record<Key, number> {
     const map: Record<Key, number> = {};
 
-    // TODO [#1637]: simplify this by assuming that all vnodes has keys
     for (let j = beginIdx; j <= endIdx; ++j) {
         const ch = children[j];
         if (isVNode(ch)) {

packages/@lwc/engine-dom/package.json

@@ -19,13 +19,17 @@
         "url": "https://github.com/salesforce/lwc/issues"
     },
     "license": "MIT",
+    "type": "module",
     "publishConfig": {
         "access": "public"
     },
+    "engines": {
+        "node": ">=16.6.0"
+    },
     "volta": {
         "extends": "../../../package.json"
     },
-    "main": "dist/index.cjs.js",
+    "main": "dist/index.js",
     "module": "dist/index.js",
     "types": "dist/index.d.ts",
     "files": [