Combine benchmark jobs with CI to get job dependencies working ok

.github/workflows/CI.yml

@@ -101,3 +101,82 @@ jobs:
           DOCUMENTER_KEY: ${{ secrets.DOCUMENTER_KEY }}
         run: |
           DISPLAY=:0 xvfb-run -s '-screen 0 1024x768x24' julia --project=docs -e 'include("docs/make.jl")'
+
+  benchmark:
+    name: Run performance regression tests
+
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        version:
+          - '1.10'
+        os:
+          - ubuntu-latest
+        arch:
+          - x64
+    steps:
+      - uses: actions/checkout@v4
+      - uses: julia-actions/setup-julia@v1
+        with:
+          version: ${{ matrix.version }}
+          arch: ${{ matrix.arch }}
+      - uses: actions/cache@v4
+        env:
+          cache-name: cache-artifacts
+        with:
+          path: ~/.julia/artifacts
+          key: runner.os−test−env.cache−name−{{ hashFiles('**/Project.toml') }}
+          restore-keys: |
+            runner.os−test−
+            ${{ env.cache-name }}-
+            ${{ runner.os }}-test-
+            ${{ runner.os }}-
+      - name: Run benchmark
+        run: |
+          julia --project=GalerkinToolkitExamples -e '
+            using Pkg
+            Pkg.develop(path=".")
+            include("GalerkinToolkitExamples/benchmarks/run_benchmarks.jl")'
+      - name: Store benchmark result
+        uses: benchmark-action/github-action-benchmark@v1
+        with:
+          name: Julia benchmark result
+          tool: 'julia'
+          output-file-path: output.json
+          gh-pages-branch: benchmarks
+          benchmark-data-dir-path: bench
+          # Use personal access token instead of GITHUB_TOKEN due to https://github.community/t/github-action-not-triggering-gh-pages-upon-push/16096
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          auto-push: true
+          # Show alert with commit comment on detecting possible performance regression
+          alert-threshold: '200%'
+          comment-on-alert: true
+          fail-on-alert: true
+
+  copybenchmarks:
+    name: Copy benchmark results to gh-pages
+    needs: [benchmark, docs]
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - name: Checkout gh-pages branch
+        uses: actions/checkout@v4
+        with:
+          ref: gh-pages
+          path: gh-pages
+      - name: Checkout benchmarks branch
+        uses: actions/checkout@v4
+        with:
+          ref: benchmarks
+          path: benchmarks
+      - name: Copy benchmark results to gh-pages
+        run: |
+          cp -r benchmarks/bench gh-pages/dev/
+          cd gh-pages
+          git config user.name github-actions
+          git config user.email [email protected]
+          git add -A
+          git commit -m 'Copy benchmark results to documentation on gh-pages'
+          git push