chore: switch to npm

.github/workflows/benchmark.yml

@@ -25,13 +25,16 @@ jobs:
               uses: actions/setup-node@v4
               with:
                   node-version: '20.18.0'
-                  cache: 'yarn'
+                  cache: 'npm'
+
+            - name: Setup npm
+              run: npm install -g [email protected]
 
             - name: Install dependencies
-              run: yarn install --frozen-lockfile
+              run: npm ci
 
             - name: Build benchmarks
-              run: yarn build:performance
+              run: npm run build:performance
 
             - name: Run benchmarks
-              run: yarn test:performance:best:ci
+              run: npm run test:performance:best:ci

.github/workflows/integration.yml

@@ -34,7 +34,10 @@ jobs:
               uses: actions/setup-node@v4
               with:
                   node-version: '20.18.0'
-                  cache: 'yarn'
+                  cache: 'npm'
+
+            - name: Setup npm
+              run: npm install -g [email protected]
 
             # Needed for local browser integration tests
             # chrome-version documentation can be found here: https://github.com/browser-actions/setup-chrome?tab=readme-ov-file#usage
@@ -45,13 +48,13 @@ jobs:
               id: setup-chrome
 
             - name: Install dependencies
-              run: yarn install --frozen-lockfile
+              run: npm ci
               working-directory: ./
 
             # Pin chromedriver to the same version as Chrome above
             - name: Install chromedriver
-              run: yarn add -W chromedriver@^130
+              run: npm install --save-dev chromedriver@^130
               working-directory: ./
 
-            - run: CHROME_BINARY=${{ steps.setup-chrome.outputs.chrome-path }} yarn local:prod:ci
-            - run: CHROME_BINARY=${{ steps.setup-chrome.outputs.chrome-path }} yarn local:dev:ci
+            - run: CHROME_BINARY=${{ steps.setup-chrome.outputs.chrome-path }} npm run local:prod:ci
+            - run: CHROME_BINARY=${{ steps.setup-chrome.outputs.chrome-path }} npm run local:dev:ci

.github/workflows/karma.yml

@@ -39,11 +39,14 @@ jobs:
             - name: Setup Node
               uses: actions/setup-node@v4
               with:
-                  node-version: ${{ env.NODE_VERSION }}
-                  cache: 'yarn'
+                node-version: ${{ env.NODE_VERSION }}
+                cache: 'npm'
+
+            - name: Setup npm
+              run: npm install -g [email protected]
 
             - name: Install dependencies
-              run: yarn install --frozen-lockfile
+              run: npm ci
               working-directory: ./
 
             - uses: saucelabs/sauce-connect-action@v2
@@ -52,12 +55,12 @@ jobs:
                   accessKey: ${{ secrets.SAUCE_ACCESS_KEY }}
                   tunnelName: ${{ env.SAUCE_TUNNEL_ID }}
 
-            - run: yarn sauce:ci
-            - run: DISABLE_SYNTHETIC=1 yarn sauce:ci
-            - run: LEGACY_BROWSERS=1 yarn sauce:ci
-            - run: FORCE_NATIVE_SHADOW_MODE_FOR_TEST=1 yarn sauce:ci
-            - run: DISABLE_NATIVE_CUSTOM_ELEMENT_LIFECYCLE=1 yarn sauce:ci
-            - run: DISABLE_NATIVE_CUSTOM_ELEMENT_LIFECYCLE=1 DISABLE_SYNTHETIC=1 yarn sauce:ci
+            - run: npm run sauce:ci
+            - run: DISABLE_SYNTHETIC=1 npm run sauce:ci
+            - run: LEGACY_BROWSERS=1 npm run sauce:ci
+            - run: FORCE_NATIVE_SHADOW_MODE_FOR_TEST=1 npm run sauce:ci
+            - run: DISABLE_NATIVE_CUSTOM_ELEMENT_LIFECYCLE=1 npm run sauce:ci
+            - run: DISABLE_NATIVE_CUSTOM_ELEMENT_LIFECYCLE=1 DISABLE_SYNTHETIC=1 npm run sauce:ci
 
             - name: Upload coverage results
               uses: actions/upload-artifact@v4
@@ -80,10 +83,13 @@ jobs:
               uses: actions/setup-node@v4
               with:
                   node-version: ${{ env.NODE_VERSION }}
-                  cache: 'yarn'
+                  cache: 'npm'
+
+            - name: Setup npm
+              run: npm install -g [email protected]
 
             - name: Install dependencies
-              run: yarn install --frozen-lockfile
+              run: npm ci
               working-directory: ./
 
             - uses: saucelabs/sauce-connect-action@v2
@@ -92,12 +98,12 @@ jobs:
                   accessKey: ${{ secrets.SAUCE_ACCESS_KEY }}
                   tunnelName: ${{ env.SAUCE_TUNNEL_ID }}
 
-            - run: API_VERSION=58 yarn sauce:ci
-            - run: API_VERSION=58 DISABLE_SYNTHETIC=1 yarn sauce:ci
-            - run: API_VERSION=59 yarn sauce:ci
-            - run: API_VERSION=59 DISABLE_SYNTHETIC=1 yarn sauce:ci
-            - run: API_VERSION=60 yarn sauce:ci
-            - run: API_VERSION=60 DISABLE_SYNTHETIC=1 yarn sauce:ci
+            - run: API_VERSION=58 npm run sauce:ci
+            - run: API_VERSION=58 DISABLE_SYNTHETIC=1 npm run sauce:ci
+            - run: API_VERSION=59 npm run sauce:ci
+            - run: API_VERSION=59 DISABLE_SYNTHETIC=1 npm run sauce:ci
+            - run: API_VERSION=60 npm run sauce:ci
+            - run: API_VERSION=60 DISABLE_SYNTHETIC=1 npm run sauce:ci
 
             - name: Upload coverage results
               uses: actions/upload-artifact@v4
@@ -120,10 +126,13 @@ jobs:
               uses: actions/setup-node@v4
               with:
                   node-version: ${{ env.NODE_VERSION }}
-                  cache: 'yarn'
+                  cache: 'npm'
+
+            - name: Setup npm
+              run: npm install -g [email protected]
 
             - name: Install dependencies
-              run: yarn install --frozen-lockfile
+              run: npm ci
               working-directory: ./
 
             - uses: saucelabs/sauce-connect-action@v2
@@ -132,14 +141,14 @@ jobs:
                   accessKey: ${{ secrets.SAUCE_ACCESS_KEY }}
                   tunnelName: ${{ env.SAUCE_TUNNEL_ID }}
 
-            - run: API_VERSION=61 yarn sauce:ci
-            - run: API_VERSION=61 DISABLE_SYNTHETIC=1 yarn sauce:ci
-            - run: API_VERSION=62 yarn sauce:ci
-            - run: API_VERSION=62 DISABLE_SYNTHETIC=1 yarn sauce:ci
-            - run: DISABLE_SYNTHETIC_SHADOW_SUPPORT_IN_COMPILER=1 DISABLE_SYNTHETIC=1 yarn sauce:ci
-            - run: DISABLE_SYNTHETIC_SHADOW_SUPPORT_IN_COMPILER=1 DISABLE_SYNTHETIC=1 DISABLE_STATIC_CONTENT_OPTIMIZATION=1 yarn sauce:ci
-            - run: ENABLE_ARIA_REFLECTION_GLOBAL_POLYFILL=1 yarn sauce:ci
-            - run: ENABLE_ARIA_REFLECTION_GLOBAL_POLYFILL=1 DISABLE_SYNTHETIC=1 yarn sauce:ci
+            - run: API_VERSION=61 npm run sauce:ci
+            - run: API_VERSION=61 DISABLE_SYNTHETIC=1 npm run sauce:ci
+            - run: API_VERSION=62 npm run sauce:ci
+            - run: API_VERSION=62 DISABLE_SYNTHETIC=1 npm run sauce:ci
+            - run: DISABLE_SYNTHETIC_SHADOW_SUPPORT_IN_COMPILER=1 DISABLE_SYNTHETIC=1 npm run sauce:ci
+            - run: DISABLE_SYNTHETIC_SHADOW_SUPPORT_IN_COMPILER=1 DISABLE_SYNTHETIC=1 DISABLE_STATIC_CONTENT_OPTIMIZATION=1 npm run sauce:ci
+            - run: ENABLE_ARIA_REFLECTION_GLOBAL_POLYFILL=1 npm run sauce:ci
+            - run: ENABLE_ARIA_REFLECTION_GLOBAL_POLYFILL=1 DISABLE_SYNTHETIC=1 npm run sauce:ci
 
             - name: Upload coverage results
               uses: actions/upload-artifact@v4
@@ -162,10 +171,13 @@ jobs:
               uses: actions/setup-node@v4
               with:
                   node-version: ${{ env.NODE_VERSION }}
-                  cache: 'yarn'
+                  cache: 'npm'
+
+            - name: Setup npm
+              run: npm install -g [email protected]
 
             - name: Install dependencies
-              run: yarn install --frozen-lockfile
+              run: npm ci
               working-directory: ./
 
             - uses: saucelabs/sauce-connect-action@v2
@@ -174,15 +186,15 @@ jobs:
                   accessKey: ${{ secrets.SAUCE_ACCESS_KEY }}
                   tunnelName: ${{ env.SAUCE_TUNNEL_ID }}
 
-            - run: DISABLE_STATIC_CONTENT_OPTIMIZATION=1 yarn sauce:ci
-            - run: DISABLE_STATIC_CONTENT_OPTIMIZATION=1 DISABLE_SYNTHETIC=1 yarn sauce:ci
-            - run: NODE_ENV_FOR_TEST=production yarn sauce:ci
-            - run: NODE_ENV_FOR_TEST=production DISABLE_SYNTHETIC=1 yarn sauce:ci
-            - run: yarn hydration:sauce:ci
-            - run: ENABLE_SYNTHETIC_SHADOW_IN_HYDRATION=1 yarn hydration:sauce:ci
-            - run: NODE_ENV_FOR_TEST=production yarn hydration:sauce:ci
-            - run: DISABLE_NATIVE_CUSTOM_ELEMENT_LIFECYCLE=1 yarn hydration:sauce:ci
-            - run: DISABLE_STATIC_CONTENT_OPTIMIZATION=1 yarn hydration:sauce:ci
+            - run: DISABLE_STATIC_CONTENT_OPTIMIZATION=1 npm run sauce:ci
+            - run: DISABLE_STATIC_CONTENT_OPTIMIZATION=1 DISABLE_SYNTHETIC=1 npm run sauce:ci
+            - run: NODE_ENV_FOR_TEST=production npm run sauce:ci
+            - run: NODE_ENV_FOR_TEST=production DISABLE_SYNTHETIC=1 npm run sauce:ci
+            - run: npm run hydration:sauce:ci
+            - run: ENABLE_SYNTHETIC_SHADOW_IN_HYDRATION=1 npm run hydration:sauce:ci
+            - run: NODE_ENV_FOR_TEST=production npm run hydration:sauce:ci
+            - run: DISABLE_NATIVE_CUSTOM_ELEMENT_LIFECYCLE=1 npm run hydration:sauce:ci
+            - run: DISABLE_STATIC_CONTENT_OPTIMIZATION=1 npm run hydration:sauce:ci
 
             - name: Upload coverage results
               uses: actions/upload-artifact@v4
@@ -207,11 +219,14 @@ jobs:
             - name: Setup Node
               uses: actions/setup-node@v4
               with:
-                  node-version: ${{ env.NODE_VERSION }}
-                  cache: 'yarn'
+                node-version: ${{ env.NODE_VERSION }}
+                cache: 'npm'
+
+            - name: Setup npm
+              run: npm install -g [email protected]
 
             - name: Install dependencies
-              run: yarn install --frozen-lockfile
+              run: npm ci
               working-directory: ./
 
             - name: Download coverage results - group 1
@@ -235,7 +250,7 @@ jobs:
                   name: coverage-report-group-4
                   path: ./packages/@lwc/integration-karma/coverage
 
-            - run: yarn coverage
+            - run: npm coverage
 
             - name: Upload combined coverage
               uses: actions/upload-artifact@v4

.github/workflows/unit.yml

@@ -30,7 +30,10 @@ jobs:
               uses: actions/setup-node@v4
               with:
                   node-version: '20.18.0'
-                  cache: 'yarn'
+                  cache: 'npm'
+
+            - name: Setup npm
+              run: npm install -g [email protected]
 
             # Needed for perf smoke tests, matches the chromedriver version installed by tachometer (https://github.com/google/tachometer/blob/main/README.md#on-demand-dependencies)
             # chrome-version documentation can be found here: https://github.com/browser-actions/setup-chrome?tab=readme-ov-file#usage
@@ -41,12 +44,12 @@ jobs:
               id: setup-chrome
 
             - name: Install dependencies
-              run: yarn install --frozen-lockfile
+              run: npm ci
 
             # Pin chromedriver to the same version as Chrome above, so Tachometer uses this version.
             # See: https://github.com/google/tachometer#on-demand-dependencies
             - name: Install chromedriver
-              run: yarn add -W chromedriver@^130
+              run: npm install --save-dev chromedriver@^130
 
             - name: Check package.json integrity
               run: node ./scripts/tasks/check-and-rewrite-package-json.js --test
@@ -57,25 +60,25 @@ jobs:
             - name: Verify that dependencies are declared
               run: node ./scripts/tasks/check-imports-are-declared-dependencies.js
             - name: Check formatting
-              run: yarn prettier --check '{packages,scripts}/**/*.{js,ts,json,md}'
+              run: npm prettier --check '{packages,scripts}/**/*.{js,ts,json,md}'
             - name: Run linter
-              run: yarn lint
+              run: npm run lint
             - name: Check the size of the LWC bundle
-              run: yarn bundlesize
+              run: npm run bundlesize
             - name: Check types
-              run: yarn test:types
+              run: npm run test:types
             - name: Run unit tests
-              run: yarn test:ci
+              run: npm run test:ci
             # TODO [#4815]: enable all SSR v2 tests
             - name: Run experimental SSR fixture tests
-              run: TEST_SSR_COMPILER=1 yarn test packages/@lwc/ssr-compiler/src/__tests__/fixtures.spec.ts
+              run: TEST_SSR_COMPILER=1 npm run test packages/@lwc/ssr-compiler/src/__tests__/fixtures.spec.ts
             - name: Upload unit test coverage report
               uses: actions/upload-artifact@v4
               with:
                   name: test-coverage-report
                   path: coverage/
             - name: Run benchmark smoke tests
-              run: CHROME_BINARY=${{ steps.setup-chrome.outputs.chrome-path }} BENCHMARK_SMOKE_TEST=1 yarn test:performance
+              run: CHROME_BINARY=${{ steps.setup-chrome.outputs.chrome-path }} BENCHMARK_SMOKE_TEST=1 npm run test:performance
             - name: Add step summary
               # 1. Remove leading/trailing "border" lines from output
               # 2. Wrap file names in backticks

.husky/commit-msg

@@ -1 +1 @@
-yarn commitlint --edit $1
+npm run commitlint --edit $1

.husky/pre-commit

@@ -1 +1 @@
-yarn lint-staged
+npm run lint-staged

.npmrc

@@ -1 +1 @@
-registry=https://registry.yarnpkg.com/
+registry=https://registry.npmjs.org/

.nucleus.yaml

@@ -52,20 +52,20 @@ jobs:
 steps:
     node-conformance:
         run:
-            command: yarn run lint
+            command: npm run lint
         after: node-build
     node-unit-tests:
         run:
-            command: yarn test
-    # this project runs yarn build after yarn install so skip explicit build step
+            command: npm run test
+    # this project runs npm run build after npm install so skip explicit build step
     node-build: &node-build
         skip: true
     node-pre-release-tests:
         params:
-            command: yarn test
+            command: npm run test
     npm-configure:
         params:
-            registry-url: https://registry.yarnpkg.com
+            registry-url: https://registry.npmjs.org
     npm-configure-for-publish:
         params:
             registry-url: https://registry.npmjs.org