feat: add build workflow

Signed-off-by: John Molakvoæ <skjnldsv@users.noreply.github.com>

.github/workflows/node.yml

@@ -0,0 +1,71 @@
+# This workflow is provided via the organization template repository
+#
+# https://github.com/nextcloud/.github
+# https://docs.github.com/en/actions/learn-github-actions/sharing-workflows-with-your-organization
+
+name: Node
+
+on:
+  pull_request:
+    paths:
+      - '.github/workflows/**'
+      - 'src/**'
+      - 'appinfo/info.xml'
+      - 'package.json'
+      - 'package-lock.json'
+      - 'tsconfig.json'
+      - '**.js'
+      - '**.ts'
+      - '**.vue'
+  push:
+    branches:
+      - main
+      - master
+      - stable*
+
+permissions:
+  contents: read
+
+concurrency:
+  group: node-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    name: node
+    steps:
+      - name: Checkout
+        uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v3.5.2
+
+      - name: Read package.json node and npm engines version
+        uses: skjnldsv/read-package-engines-version-actions@8205673bab74a63eb9b8093402fd9e0e018663a1 # v2.2
+        id: versions
+        with:
+          fallbackNode: '^16'
+          fallbackNpm: '^7'
+
+      - name: Set up node ${{ steps.versions.outputs.nodeVersion }}
+        uses: actions/setup-node@64ed1c7eab4cce3362f8c340dee64e5eaeef8f7c # v3
+        with:
+          node-version: ${{ steps.versions.outputs.nodeVersion }}
+
+      - name: Set up npm ${{ steps.versions.outputs.npmVersion }}
+        run: npm i -g npm@"${{ steps.versions.outputs.npmVersion }}"
+
+      - name: Install dependencies & build
+        run: |
+          npm ci
+          npm run build --if-present
+
+      - name: Check webpack build changes
+        run: |
+          bash -c "[[ ! \"`git status --porcelain `\" ]] || (echo 'Please recompile and commit the assets, see the section \"Show changes on failure\" for details' && exit 1)"
+
+      - name: Show changes on failure
+        if: failure()
+        run: |
+          git status
+          git --no-pager diff
+          exit 1 # make it red to grab attention