Test documentation website build in CI, remove redundant steps from CI

.github/workflows/ci.yml

@@ -211,32 +211,6 @@ jobs:
         path: haddocks.tgz
         retention-days: 1
 
-    # NB: build the haddocks at the end to avoid unecessary recompilations.
-    # We build the haddocks only for one GHC version.
-    - name: Build Haddock documentation
-      if: |
-        github.event_name == 'push'
-        && github.ref == 'refs/heads/main'
-        && matrix.os=='ubuntu-latest'
-        && matrix.ghc=='8.10.7'
-      run: |
-        cabal build --dry-run --enable-tests all
-        ./scripts/docs/haddocks.sh
-        tar vzcf haddocks.tgz ./docs/website/static/haddocks
-
-    - name: Upload haddocks as an artifact
-      if: |
-        github.event_name == 'push'
-        && github.ref == 'refs/heads/main'
-        && matrix.os=='ubuntu-latest'
-        && matrix.ghc=='8.10.7'
-      uses: actions/upload-artifact@v3
-      with:
-        name: haddocks
-        path: haddocks.tgz
-        retention-days: 1
-
-
   deploy-documentation:
     name: Deploy documentation to GitHub Pages
     if: github.event_name == 'push' && github.ref == 'refs/heads/main'

.github/workflows/documentation.yml

@@ -0,0 +1,38 @@
+name: Documentation
+
+# Limit concurrent runs of this workflow within a single PR
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+on:
+  pull_request:
+
+jobs:
+  # https://docusaurus.io/docs/deployment#triggering-deployment-with-github-actions
+  #
+  # We test the website build on pull requests, without building any static
+  # assets (pdfs, haddocks), and without deploying the website to github-pages.
+  # The build should still succeed regardless, and serves as a check before we
+  # deploy the documentation website on the default branch.
+  test-deploy-documentation:
+    name: Test documentation deployment
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: ./docs/website
+    strategy:
+       fail-fast: false
+
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with:
+          node-version: 18
+          cache: yarn
+          cache-dependency-path: './docs/website/yarn.lock'
+
+      - name: Install dependencies
+        run: yarn install --frozen-lockfile
+      - name: Test build website
+        run: yarn build