fix json parsing

Author: tylerhutcherson

.github/workflows/test.yml

@@ -42,11 +42,16 @@ jobs:
               FILTERED_NBS+=("$nb")
             fi
           done
+          
+          NB_JSON=$(printf '%s\n' "${FILTERED_NBS[@]}" | jq -R . | jq -s -c .)
 
-          # Convert filtered list into JSON array so it can be passed to matrix
-          NB_JSON=$(printf '%s\n' "${FILTERED_NBS[@]}" | jq -R . | jq -s .)
-          echo "Changed notebooks: $NB_JSON"
-          echo "::set-output name=notebooks::$NB_JSON"
+          # Ensure at least "[]" if empty
+          if [ -z "$NB_JSON" ] || [ "$NB_JSON" = "[]" ]; then
+            NB_JSON="[]"
+          fi
+
+          echo "All valid notebooks: $NB_JSON"
+          echo "notebooks=$NB_JSON" >> $GITHUB_OUTPUT
 
   # ---------------------------------------------------------
   # 2) Test each changed notebook in parallel