Enable PR previews (#3)

* Enable PR previews

* Don't worry about baseurl for now

* Use a different sed separator

.github/workflows/deploy-preview.yml

@@ -0,0 +1,61 @@
+name: deploy-book-preview
+
+on:
+  pull_request:
+    types:
+      - opened
+      - reopened
+      - synchronize
+      - closed
+
+concurrency: preview-${{ github.ref }}
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+
+    concurrency: pages-main
+
+    steps:
+      - name: Checkout book
+        uses: actions/checkout@v4
+
+      - name: Setup Python 3.12
+        if: github.event.action != 'closed'
+        uses: actions/setup-python@v5
+        with:
+          python-version: 3.12
+
+      - name: Install dependencies
+        if: github.event.action != 'closed'
+        run: |
+          pip install -r requirements.txt
+
+      - name: Get GitHub Pages URL
+        id: pages
+        if: github.event.action != 'closed'
+        uses: actions/configure-pages@v4
+
+      - name: Replace base URL
+        if: github.event.action != 'closed'
+        run: |
+          sed -i 's~baseurl: ""~baseurl: "${{ steps.pages.outputs.base_url }}/preview/pr-${{ github.event.number }}"~g' _config.yml
+
+      - name: Build book
+        if: github.event.action != 'closed'
+        run: |
+          jupyter-book build .
+
+      - name: Disable Jekyll to serve static HTML
+        run: |
+          touch _build/html/.nojekyll
+
+      - name: Commit preview to Pages branch
+        uses: rossjrw/pr-preview-action@v1.4.7
+        with:
+          source-dir: "_build/html"
+          umbrella-dir: preview

.github/workflows/deploy.yml

@@ -28,11 +28,12 @@ jobs:
           pip install -r requirements.txt
 
       - name: Get GitHub Pages URL
+        id: pages
         uses: actions/configure-pages@v4
 
       - name: Replace base URL
         run: |
-          sed -i 's/baseurl: ""/baseurl: "${{ steps.pages.outputs.base_url }}"/g' _config.yml
+          sed -i 's~baseurl: ""~baseurl: "${{ steps.pages.outputs.base_url }}"~g' _config.yml
 
       - name: Build book
         run: |
@@ -45,4 +46,6 @@ jobs:
       - name: Deploy book to GitHub Pages
         uses: JamesIves/github-pages-deploy-action@v4
         with:
+          clean-exclude: preview
           folder: "_build/html"
+          force: false