bulk_inference: fix tests on pypy

The bulk_inference code is now multithreaded. For this reason, the trick of
returning different values in the Mock based on the order of the calls no longer works.
This was somewhat accidentally working on CPython, but not on pypy.

Author: mhaas

tests/sap/aibus/dar/client/test_inference_client.py

@@ -3,7 +3,7 @@
 # mypy cannot deal with some of the monkey-patching we do below.
 # https://github.com/python/mypy/issues/2427
 from typing import Optional
-from unittest.mock import call
+from unittest.mock import call, Mock
 
 import pytest
 from requests import RequestException, Timeout
@@ -267,20 +267,41 @@ def test_bulk_inference_error(self, inference_client: InferenceClient):
 
         exception_404 = DARHTTPException.create_from_response(url, response_404)
 
+        # The old trick to return different values in a Mock based on the call order
+        # does not work here because the code is concurrent. Instead, we use a different
+        # objectId for those objects where we want the request to fail
+        def make_mock_post(exc):
+            def post_to_endpoint(*args, **kwargs):
+                payload = kwargs.pop("payload")
+                object_id = payload["objects"][0]["objectId"]
+                if object_id == "expected-to-fail":
+                    raise exc
+                elif object_id == "b5cbcb34-7ab9-4da5-b7ec-654c90757eb9":
+                    response = Mock()
+                    response.json.return_value = self.inference_response(
+                        len(payload["objects"])
+                    )
+                    return response
+                else:
+                    raise ValueError(f"objectId '{object_id}' not handled in test.")
+
+            return post_to_endpoint
+
+        # Try different exceptions
         exceptions = [
             exception_404,
             RequestException("Request Error"),
             Timeout("Timeout"),
         ]
-        # Try different exceptions
         for exc in exceptions:
-            inference_client.session.post_to_endpoint.return_value.json.side_effect = [
-                self.inference_response(50),
-                exc,
-                self.inference_response(40),
-            ]
+            inference_client.session.post_to_endpoint.side_effect = make_mock_post(exc)
 
-            many_objects = [self.objects()[0] for _ in range(50 + 50 + 40)]
+            many_objects = []
+            many_objects.extend([self.objects()[0] for _ in range(50)])
+            many_objects.extend(
+                [self.objects(object_id="expected-to-fail")[0] for _ in range(50)]
+            )
+            many_objects.extend([self.objects()[0] for _ in range(40)])
             assert len(many_objects) == 50 + 50 + 40
 
             response = inference_client.do_bulk_inference(
@@ -290,7 +311,7 @@ def test_bulk_inference_error(self, inference_client: InferenceClient):
             )
 
             expected_error_response = {
-                "objectId": "b5cbcb34-7ab9-4da5-b7ec-654c90757eb9",
+                "objectId": "expected-to-fail",
                 "labels": None,
                 # If this test fails, I found it can make pytest/PyCharm hang because it
                 # takes too much time in difflib.
@@ -302,6 +323,7 @@ def test_bulk_inference_error(self, inference_client: InferenceClient):
             expected_response.extend(expected_error_response for _ in range(50))
             expected_response.extend(self.inference_response(40)["predictions"])
 
+            assert len(response) == len(expected_response)
             assert response == expected_response
 
     def test_bulk_inference_error_no_object_ids(