Extend tf weight converter test

Author: constantinpape

tests/weight_converter/keras/test_tensorflow.py

@@ -1,3 +1,6 @@
+import zipfile
+
+
 def test_tensorflow_converter(any_keras_model, tmp_path):
     from bioimageio.core.weight_converter.keras import convert_weights_to_tensorflow_saved_model_bundle
 
@@ -16,3 +19,9 @@ def test_tensorflow_converter_zipped(any_keras_model, tmp_path):
     ret_val = convert_weights_to_tensorflow_saved_model_bundle(any_keras_model, out_path)
     assert out_path.exists()
     assert ret_val == 0  # check for correctness is done in converter and returns 0 if it passes
+
+    # make sure that the zip package was created correctly
+    expected_names = {"saved_model.pb", "variables/variables.index"}
+    with zipfile.ZipFile(out_path, "r") as f:
+        names = set([name for name in f.namelist()])
+    assert len(expected_names - names) == 0