CI: Require at least one code block separator for example files in the Style Checks workflow

Author: seisman

.github/workflows/style_checks.yaml

@@ -49,3 +49,14 @@ jobs:
           find . -type f -not -path '*/\.git/*' -exec grep -Iq . {} \; -exec dos2unix --quiet {} \;
           find . -type f -not -path '*/\.git/*' -exec grep -Iq . {} \; -exec chmod 644 {} \;
           if [[ $(git ls-files -m) ]]; then git --no-pager diff HEAD; exit 1; fi
+
+      - name: Ensure example scripts have at least one code block separator
+        run: |
+          grep -L '# %%' $(find 'examples' -name '*.py') > output.txt
+          nfiles=$(wc -l output.txt | awk '{print $1}')
+          if [[ $nfiles > 0 ]]; then
+            echo "Code block separator '# %%' is required in following example files:"
+            cat output.txt
+            rm output.txt
+            exit $nfiles
+          fi