chore: update gen-readme workflow

Author: aarondill

.github/workflows/gen-readme.yml

@@ -13,20 +13,42 @@ jobs:
       contents: write
     steps:
       - uses: actions/checkout@master
-      - run: |
-          [ -f README.tmpl.md ] || cp README.md README.tmpl.md # Initialize README.tmpl.md
+        with: # We need to fetch enough commits to check if we've waited long enough
+          fetch-depth: 12
+      - name: Check if we've waited long enough (10+ commits)
+        id: commit-count
+        continue-on-error: true
+        run: |
+          [ '${{ github.event_name }}' != 'workflow_dispatch' ] || exit 0
+          last_sha=$(git log --oneline --format=format:%H --grep="^chore: Generate README$" -1)
+          echo "last_sha=$last_sha"
+          if [ -n "$last_sha" ]; then # success if last_sha is empty
+            count=$(git rev-list $last_sha..HEAD --count)
+            echo "count=$count"
+            [ $count -gt 10 ] || exit 1
+          fi
+      - name: Initialize README.md
+        if: ${{ steps.commit-count.outcome == 'success' }}
+        run: |
+          [ -f README.tmpl.md ] || cp README.md README.tmpl.md
           printf '%s\n' "<!-- This file is generated from README.tmpl.md -->" > README.md
           cat README.tmpl.md >> README.md
       - name: CLOC
+        if: ${{ steps.commit-count.outcome == 'success' }}
         uses: djdefi/cloc-action@6
         with:
           options: --md --report-file=cloc.md --hide-rate
         # Note: initial newline is required because files don't end with one
-      - run: |
-          printf '\n%s\n' '### Lines of code' >> README.md
+      - name: Update README
+        if: ${{ steps.commit-count.outcome == 'success' }}
+        run: |
+          printf '\n' >> README.md
+          printf '%s\n' '### Lines of code' "<sup><sub>Generated at commit $(git rev-parse HEAD)</sub></sup>" >> README.md
           cat cloc.md >> README.md
           rm cloc.md
-      - uses: stefanzweifel/git-auto-commit-action@v4
+      - name: Commit README
+        uses: stefanzweifel/git-auto-commit-action@v4
+        if: ${{ steps.commit-count.outcome == 'success' }}
         with:
           commit_message: "chore: Generate README"
           # Note: README.tmpl.md is needed in the first case