Fix QA argument handler (#8765)

* Fix QA argument handler

* Attempt to get a better fix for QA (#8768)
Co-authored-by: Nicolas Patry <patry.nicolas@protonmail.com>

src/transformers/pipelines.py

@@ -1624,7 +1624,17 @@ class QuestionAnsweringArgumentHandler(ArgumentHandler):
         elif "data" in kwargs:
             inputs = kwargs["data"]
         elif "question" in kwargs and "context" in kwargs:
+            if isinstance(kwargs["question"], list) and isinstance(kwargs["context"], str):
+                inputs = [{"question": Q, "context": kwargs["context"]} for Q in kwargs["question"]]
+            elif isinstance(kwargs["question"], list) and isinstance(kwargs["context"], list):
+                if len(kwargs["question"]) != len(kwargs["context"]):
+                    raise ValueError("Questions and contexts don't have the same lengths")
+
+                inputs = [{"question": Q, "context": C} for Q, C in zip(kwargs["question"], kwargs["context"])]
+            elif isinstance(kwargs["question"], str) and isinstance(kwargs["context"], str):
                 inputs = [{"question": kwargs["question"], "context": kwargs["context"]}]
+            else:
+                raise ValueError("Arguments can't be understood")
         else:
             raise ValueError("Unknown arguments {}".format(kwargs))
 

tests/test_pipelines_question_answering.py

@@ -23,6 +23,17 @@ class QAPipelineTests(CustomInputPipelineCommonMixin, unittest.TestCase):
             "question": "In what field is HuggingFace working ?",
             "context": "HuggingFace is a startup based in New-York founded in Paris which is trying to solve NLP.",
         },
+        {
+            "question": ["In what field is HuggingFace working ?", "In what field is HuggingFace working ?"],
+            "context": "HuggingFace is a startup based in New-York founded in Paris which is trying to solve NLP.",
+        },
+        {
+            "question": ["In what field is HuggingFace working ?", "In what field is HuggingFace working ?"],
+            "context": [
+                "HuggingFace is a startup based in New-York founded in Paris which is trying to solve NLP.",
+                "HuggingFace is a startup based in New-York founded in Paris which is trying to solve NLP.",
+            ],
+        },
     ]
 
     def _test_pipeline(self, nlp: Pipeline):
@@ -80,6 +91,11 @@ class QAPipelineTests(CustomInputPipelineCommonMixin, unittest.TestCase):
         self.assertEqual(len(normalized), 1)
         self.assertEqual({type(el) for el in normalized}, {SquadExample})
 
+        normalized = qa(question=[Q, Q], context=C)
+        self.assertEqual(type(normalized), list)
+        self.assertEqual(len(normalized), 2)
+        self.assertEqual({type(el) for el in normalized}, {SquadExample})
+
         normalized = qa({"question": Q, "context": C})
         self.assertEqual(type(normalized), list)
         self.assertEqual(len(normalized), 1)
@@ -159,6 +175,26 @@ class QAPipelineTests(CustomInputPipelineCommonMixin, unittest.TestCase):
         with self.assertRaises(ValueError):
             qa([{"question": Q, "context": C}, {"question": Q, "context": ""}])
 
+        with self.assertRaises(ValueError):
+            qa(question={"This": "Is weird"}, context="This is a context")
+
+        with self.assertRaises(ValueError):
+            qa(question=[Q, Q], context=[C, C, C])
+
+        with self.assertRaises(ValueError):
+            qa(question=[Q, Q, Q], context=[C, C])
+
+    def test_argument_handler_old_format(self):
+        qa = QuestionAnsweringArgumentHandler()
+
+        Q = "Where was HuggingFace founded ?"
+        C = "HuggingFace was founded in Paris"
+        # Backward compatibility for this
+        normalized = qa(question=[Q, Q], context=[C, C])
+        self.assertEqual(type(normalized), list)
+        self.assertEqual(len(normalized), 2)
+        self.assertEqual({type(el) for el in normalized}, {SquadExample})
+
     def test_argument_handler_error_handling_odd(self):
         qa = QuestionAnsweringArgumentHandler()
         with self.assertRaises(ValueError):