ci: update Next.js deployment workflow for GitHub Pages

- Replace old deploy.yml with new nextjs.yml workflow
- Configure Next.js for static export with basePath support
- Add proper caching and package manager detection
- Update deployment steps to match Next.js requirements

Author: Mahdirnj

.github/workflows/deploy.yml

@@ -0,0 +1,85 @@
+name: Deploy Next.js site to Pages
+
+on:
+  push:
+    branches: ["main"]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: "pages"
+  cancel-in-progress: false
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Detect package manager
+        id: detect-package-manager
+        run: |
+          if [ -f "${{ github.workspace }}/yarn.lock" ]; then
+            echo "manager=yarn" >> $GITHUB_OUTPUT
+            echo "command=install" >> $GITHUB_OUTPUT
+            echo "runner=yarn" >> $GITHUB_OUTPUT
+            exit 0
+          elif [ -f "${{ github.workspace }}/package.json" ]; then
+            echo "manager=npm" >> $GITHUB_OUTPUT
+            echo "command=ci" >> $GITHUB_OUTPUT
+            echo "runner=npx --no-install" >> $GITHUB_OUTPUT
+            exit 0
+          else
+            echo "Unable to determine package manager"
+            exit 1
+          fi
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+          cache: ${{ steps.detect-package-manager.outputs.manager }}
+
+      - name: Setup Pages
+        uses: actions/configure-pages@v5
+        with:
+          static_site_generator: next
+
+      - name: Restore cache
+        uses: actions/cache@v4
+        with:
+          path: |
+            .next/cache
+          key: ${{ runner.os }}-nextjs-${{ hashFiles('**/package-lock.json', '**/yarn.lock') }}-${{ hashFiles('**.[jt]s', '**.[jt]sx') }}
+          restore-keys: |
+            ${{ runner.os }}-nextjs-${{ hashFiles('**/package-lock.json', '**/yarn.lock') }}-
+
+      - name: Install dependencies
+        run: ${{ steps.detect-package-manager.outputs.manager }} ${{ steps.detect-package-manager.outputs.command }}
+
+      - name: Build with Next.js
+        run: ${{ steps.detect-package-manager.outputs.runner }} next build
+
+      - name: Static export (ensure out/ exists)
+        run: ${{ steps.detect-package-manager.outputs.runner }} next export
+
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: ./out
+
+  deploy:
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4

.github/workflows/nextjs.yml

@@ -1,7 +1,23 @@
 import type { NextConfig } from "next";
 
+// Optional base path for Project Pages (https://<user>.github.io/<repo>)
+// Set via env: NEXT_PUBLIC_BASE_PATH="/<repo>"
+const basePath = process.env.NEXT_PUBLIC_BASE_PATH || "";
+
 const nextConfig: NextConfig = {
-  /* config options here */
+  // Generate a static export for GitHub Pages
+  output: "export",
+
+  // Apply basePath only when provided (for Project Pages). For User/Org Pages, leave empty.
+  ...(basePath
+    ? {
+        basePath,
+        assetPrefix: `${basePath}/`,
+      }
+    : {}),
+
+  // If you use next/image, set unoptimized for static export.
+  images: { unoptimized: true },
 };
 
 export default nextConfig;