ci: optimize the doc translation pipeline to run partial changes

Author: seratch

.github/workflows/update-docs.yml

@@ -38,27 +38,79 @@ jobs:
         uses: actions/checkout@v6
         with:
           fetch-depth: 0
+      - name: Detect translation scope
+        id: translate-scope
+        shell: bash
+        run: |
+          set -euo pipefail
+          before="${{ github.event.before }}"
+          sha="${{ github.sha }}"
+          changed_files=$(git diff --name-only --diff-filter=ACMR "$before" "$sha" -- docs mkdocs.yml || true)
+          page_list="$(mktemp "${RUNNER_TEMP}/page-files-XXXXXX.txt")"
+          non_page_found=false
+          while IFS= read -r file; do
+            if [ -z "$file" ]; then
+              continue
+            fi
+            if [[ "$file" =~ ^docs/.*\.md$ ]] \
+              && [[ ! "$file" =~ ^docs/(ja|ko|zh)/ ]] \
+              && [[ ! "$file" =~ ^docs/ref/ ]]; then
+              if [ -f "$file" ]; then
+                echo "$file" >> "$page_list"
+              fi
+            else
+              non_page_found=true
+            fi
+          done <<< "$changed_files"
+
+          if [ -s "$page_list" ] && [ "$non_page_found" = "false" ]; then
+            echo "mode=partial" >> "$GITHUB_OUTPUT"
+            echo "page_files=$page_list" >> "$GITHUB_OUTPUT"
+          else
+            echo "mode=full" >> "$GITHUB_OUTPUT"
+            rm -f "$page_list"
+          fi
       - name: Setup uv
         uses: astral-sh/setup-uv@v5
         with:
           enable-cache: true
       - name: Install dependencies
         run: make sync
-      - name: Build full docs
-        run: make build-full-docs
+      - name: Build translated docs
+        run: |
+          if [ "${{ steps.translate-scope.outputs.mode }}" = "partial" ]; then
+            echo "Translating changed pages only."
+            while IFS= read -r file; do
+              if [ -n "$file" ]; then
+                uv run docs/scripts/translate_docs.py --file "$file"
+              fi
+            done < "${{ steps.translate-scope.outputs.page_files }}"
+            uv run mkdocs build
+          else
+            echo "Translating full docs set."
+            make build-full-docs
+          fi
+
+      - name: Cleanup temp page list
+        if: steps.translate-scope.outputs.mode == 'partial'
+        run: |
+          page_list="${{ steps.translate-scope.outputs.page_files }}"
+          if [ -n "$page_list" ] && [ -f "$page_list" ]; then
+            rm -f "$page_list"
+          fi
 
       - name: Commit changes
         id: commit
         run: |
           git config user.name "github-actions[bot]"
           git config user.email "github-actions[bot]@users.noreply.github.com"
           git add docs/
-          if [ -n "$(git status --porcelain)" ]; then
-            git commit -m "Update all translated document pages"
-            echo "committed=true" >> "$GITHUB_OUTPUT"
-          else
+          if git diff --cached --quiet; then
             echo "No changes to commit"
             echo "committed=false" >> "$GITHUB_OUTPUT"
+          else
+            git commit -m "Update all translated document pages"
+            echo "committed=true" >> "$GITHUB_OUTPUT"
           fi
 
       - name: Create Pull Request