add: pull request page preview

.github/workflows/CI.yml

@@ -1,9 +1,8 @@
 name: CI
 
 on:
+  pull_request:
   push:
-    branches:
-      - main
 
 permissions:
   contents: read
@@ -14,46 +13,8 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - name: Checkout repo
+        uses: actions/checkout@v4
 
-      - uses: peaceiris/actions-mdbook@v2
-        with:
-          mdbook-version: "latest"
-
-      - name: Build mdbook
-        run: mdbook build --dest-dir out
-
-      - name: Cache Cargo registry and Cargo bin
-        id: cargo-cache
-        uses: actions/cache@v5
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            ~/.cargo/bin
-          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock','**/Cargo.toml') }}
-          restore-keys: |
-            ${{ runner.os }}-cargo-
-
-      - name: Install mdbook-utils
-        if: steps.cargo-cache.outputs.cache-hit != 'true'
-        run: cargo install mdbook-utils
-
-      - name: Generate sitemap
-        run: mdbook-utils sitemap -o out/sitemap.xml -b https://rsdocsjp.org/ -y
-
-      - name: Upload Pages artifact
-        uses: actions/upload-pages-artifact@v4
-        with:
-          path: ./out
-
-  deploy:
-    needs: build
-    runs-on: ubuntu-latest
-    environment:
-      name: github-pages
-      url: ${{ steps.deployment.outputs.page_url }}
-    steps:
-      - name: Deploy
-        id: deployment
-        uses: actions/deploy-pages@v4
+      - name: Build Check
+        uses: ./.github/workflows/build

.github/workflows/build/action.yml

@@ -0,0 +1,34 @@
+name: Build
+
+runs:
+    using: 'composite'
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Install mdbook
+        uses: peaceiris/actions-mdbook@v2
+        with:
+          mdbook-version: "latest"
+
+      - name: Build mdbook
+        run: mdbook build --dest-dir out
+
+      - name: Cache Cargo registry and Cargo bin
+        id: cargo-cache
+        uses: actions/cache@v5
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            ~/.cargo/bin
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock','**/Cargo.toml') }}
+          restore-keys: |
+            ${{ runner.os }}-cargo-
+
+      - name: Install mdbook-utils
+        if: steps.cargo-cache.outputs.cache-hit != 'true'
+        run: cargo install mdbook-utils
+
+      - name: Generate sitemap
+        run: mdbook-utils sitemap -o out/sitemap.xml -b https://rsdocsjp.org/ -y

.github/workflows/deploy.yml

@@ -0,0 +1,63 @@
+name: Deploy site to Github Pages
+
+on:
+  push:
+    branches: ["main"]
+  workflow_dispatch:
+
+permissions:
+  contents: write
+
+concurrency:
+  group: "pages"
+  cancel-in-progress: true
+
+jobs:
+  build-and-commit:
+    name: Deploy
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Build Check
+        uses: ./.github/workflows/build
+
+      - name: Move out directory
+        run: |
+            mkdir -p tmp/out
+            mv out tmp/out
+
+      - name: Checkout gh-pages
+        uses: actions/checkout@v4
+        with:
+          ref: gh-pages
+
+      - name: Preserve specific directories
+        run: |
+            mkdir -p preserve
+            mv out/preview preserve/preview
+
+      - name: Adapt new build
+        run: |
+            mv -f tmp/out out
+            mv -f preserve/preview out/preview
+
+      - name: Clean
+        run: |
+          find . -type f ! -path "./.github/*" ! -path "./out/*" ! -path "./.git/*" -delete
+
+      - name: Commit changes to gh-pages branch
+        run: |
+            git config --global user.name "GitHub Actions"
+            git config --global user.email "action@github.com"
+            git add -N .
+            set +e
+            git diff --exit-code --quiet
+            if [[ $? -eq 1 ]]; then
+                git add .
+                git commit -m "Deploy to gh-pages: ${{ github.sha }}"
+                git push origin gh-pages
+            fi

.github/workflows/gh-pages.yml

@@ -0,0 +1,40 @@
+name: Deploy site to Github Pages
+
+on:
+  push:
+    branches: ["gh-pages"]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: "pages"
+  cancel-in-progress: true
+
+jobs:
+  deploy:
+    name: Deploy
+
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          ref: gh-pages
+
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: ./out
+
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4

.github/workflows/preview.yml

@@ -0,0 +1,75 @@
+name: Deploy PR previews
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened, closed]
+
+permissions:
+  contents: write
+  pull-requests: write
+
+concurrency:
+  group: pr-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+env:
+  PAGE_DIR: pr-preview-${{ github.event.pull_request.number }}
+
+jobs:
+  build-and-commit:
+    if: github.event.action != 'closed'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Build Check
+        uses: ./.github/workflows/build
+
+      - name: Move out directory
+        run: |
+            mkdir -p tmp/out
+            mv -f out tmp/out
+
+      - name: Checkout gh-pages
+        uses: actions/checkout@v4
+        with:
+          ref: gh-pages
+
+      - name: Commit changes to gh-pages branch
+        run: |
+          git config --global user.name "GitHub Actions"
+          git config --global user.email "action@github.com"
+          mkdir -p out/preview/${{ env.PAGE_DIR }}
+          mv tmp/out /out/preview/${{ env.PAGE_DIR }}
+          git add .
+          git commit -m "Deploy PR preview for #${{ github.event.pull_request.number }}"
+          git push origin gh-pages
+
+      - name: Comment PR
+        uses: actions/github-script@v7
+        with:
+          script: |
+            github.rest.issues.createComment({
+              issue_number: context.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              body: `Preview deployed to: https://${context.repo.owner}.github.io/preview/${process.env.PAGE_DIR}`
+            })
+
+  cleanup:
+    if: github.event.action == 'closed'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout gh-pages
+        uses: actions/checkout@v4
+        with:
+          ref: gh-pages
+
+      - name: Remove preview directory
+        run: |
+            rm -rf ./out/preview/${{ env.PAGE_DIR }} || exit 0
+            git config user.name github-actions
+            git config user.email github-actions@github.com
+            git add .
+            git commit -m "Remove PR preview for #${{ github.event.pull_request.number }}" && git push origin gh-pages || echo "No changes to commit"