Simplify npm publish workflow

Author: jozefizso

.github/workflows/publish.yml

@@ -11,10 +11,12 @@ permissions:
   artifact-metadata: write
 
 jobs:
-  publish:
-    name: publish to npmjs
+  check:
+    name: check npm package version
     if: github.event.release.prerelease == false
     runs-on: ubuntu-latest
+    outputs:
+      should_publish: ${{ steps.npm_version.outputs.should_publish }}
 
     steps:
       - name: checkout
@@ -25,13 +27,37 @@ jobs:
         with:
           node-version: 24
           registry-url: https://registry.npmjs.org
-          cache: npm
 
-      - name: verify publish toolchain
+      - name: check npm package version
+        id: npm_version
         run: |
-          node --version
-          npm --version
-          node -e "const version = require('node:child_process').execFileSync('npm', ['--version'], { encoding: 'utf8' }).trim(); const [major, minor, patch] = version.split('.').map(Number); if (major < 11 || (major === 11 && (minor < 5 || (minor === 5 && patch < 1)))) throw new Error('npm 11.5.1 or newer is required for trusted publishing')"
+          package_name="$(node -p "require('./package.json').name")"
+          package_version="$(node -p "require('./package.json').version")"
+
+          if npm view "${package_name}@${package_version}" version --json >/dev/null 2>&1; then
+            echo "${package_name}@${package_version} is already published; exiting without publishing."
+            echo "should_publish=false" >> "$GITHUB_OUTPUT"
+          else
+            echo "${package_name}@${package_version} is not published yet; continuing."
+            echo "should_publish=true" >> "$GITHUB_OUTPUT"
+          fi
+
+  publish:
+    name: publish to npmjs
+    needs: check
+    if: needs.check.outputs.should_publish == 'true'
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: checkout
+        uses: actions/checkout@v6
+
+      - name: setup node 24
+        uses: actions/setup-node@v6
+        with:
+          node-version: 24
+          registry-url: https://registry.npmjs.org
+          cache: npm
 
       - name: install dependencies
         run: npm ci
@@ -45,22 +71,7 @@ jobs:
       - name: verify runtime dependency tree
         run: npm ls --omit=dev --all
 
-      - name: check npm package version
-        id: npm_version
-        run: |
-          package_name="$(node -p "require('./package.json').name")"
-          package_version="$(node -p "require('./package.json').version")"
-
-          if npm view "${package_name}@${package_version}" version --json >/dev/null 2>&1; then
-            echo "exists=true" >> "$GITHUB_OUTPUT"
-          else
-            echo "exists=false" >> "$GITHUB_OUTPUT"
-          fi
-
-          echo "package=${package_name}@${package_version}" >> "$GITHUB_OUTPUT"
-
       - name: pack package
-        if: steps.npm_version.outputs.exists == 'false'
         id: pack
         run: |
           mkdir -p dist
@@ -70,21 +81,18 @@ jobs:
           echo "tarball=$tarball" >> "$GITHUB_OUTPUT"
 
       - name: attest npm package artifact
-        if: steps.npm_version.outputs.exists == 'false'
         uses: actions/attest@v4
         with:
           subject-path: ${{ steps.pack.outputs.tarball }}
 
       - name: upload npm package artifact
-        if: steps.npm_version.outputs.exists == 'false'
         uses: actions/upload-artifact@v4
         with:
           name: npm-package
           path: ${{ steps.pack.outputs.tarball }}
           if-no-files-found: error
 
       - name: publish package
-        if: steps.npm_version.outputs.exists == 'false'
         run: npm publish "$TARBALL" --provenance --access public
         env:
           TARBALL: ${{ steps.pack.outputs.tarball }}