test the zip files

.github/workflows/check_export.yml

@@ -19,20 +19,30 @@ jobs:
                 exit 1
               fi
               pushd $f
+
+              if !( grep -w "^reflex" requirements.txt >/dev/null 2>&1 ); then
+                echo "$f/requirements.txt does not contain 'reflex'"
+                exit 1
+              fi
+
               python -m venv venv
               source venv/bin/activate
+
               # pin reflex version - no moving target
               pip install reflex==0.2.7
               pip install -r requirements.txt
               reflex init
               reflex export
+              for a in frontend.zip backend.zip; do
+                if unzip -t "$a"; then
+                  echo "$a prepared as expected"
+                else
+                  echo "ERROR: $a is not a valid zip file"
+                  exit 1
+                fi
+              done
+
               deactivate
-              if ls frontend.zip backend.zip; then
-                echo "Archives prepared as expected"
-              else
-                echo "ERROR: Archives not prepared as expected"
-                exit 1
-              fi
               popd
             fi
           done