check-md-links.yml

name: Check Markdown Links

on:
  pull_request:
    types: [opened, synchronize, reopened]

jobs:
  check-md-links:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout PR
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: '3.11'

      - name: Collect added/modified Markdown files
        id: changed
        run: |
          # Only added (A) or modified (M) files in this PR — deletions and renames-source are skipped.
          # Three-dot diff (BASE...HEAD) gives the PR's own changes vs. the merge-base,
          # so commits that landed on the base branch after this PR diverged are excluded.
          {
            echo 'files<<EOF'
            git diff --name-only --diff-filter=AM \
              "${{ github.event.pull_request.base.sha }}...HEAD" \
              -- 'docs/**/*.md' 'docs/**/*.mdx' \
                 'i18n/zh-CN/docusaurus-plugin-content-docs/current/**/*.md' \
                 'i18n/zh-CN/docusaurus-plugin-content-docs/current/**/*.mdx'
            echo EOF
          } >> "$GITHUB_OUTPUT"

      - name: Check links in changed Markdown files
        run: |
          set -u
          FILES="${{ steps.changed.outputs.files }}"
          if [ -z "$FILES" ]; then
            echo "No Markdown files added or modified in this PR. Skipping."
            exit 0
          fi

          echo "Markdown files to check:"
          echo "$FILES"
          echo "------------------------------------------------------------"

          FAILED=()
          while IFS= read -r file; do
            [ -z "$file" ] && continue
            if [ ! -f "$file" ]; then
              echo "Skip (not found in working tree): $file"
              continue
            fi
            echo
            echo "=== Checking: $file ==="
            if ! python3 scripts/check_md_links_single.py "$file" --no-external; then
              FAILED+=("$file")
            fi
          done <<< "$FILES"

          echo
          echo "============================================================"
          if [ ${#FAILED[@]} -gt 0 ]; then
            echo "❌ Broken internal links found in ${#FAILED[@]} file(s):"
            for f in "${FAILED[@]}"; do
              echo "   - $f"
            done
            exit 1
          fi
          echo "✅ All checked Markdown files have valid internal links."