Deprecate conversation support in TextGeneration in favour of `Chat…

…Generation` (#676)

* Deprecate conversation support in `TextGeneration`

* Fix linting issue from `develop` merge

src/distilabel/distiset.py

@@ -224,7 +224,7 @@ def create_distiset(  # noqa: C901
         correspond to different configurations of the dataset.
     """
     from distilabel.steps.constants import DISTILABEL_METADATA_KEY
-    
+
     logger = logging.getLogger("distilabel.distiset")
 
     data_dir = Path(data_dir)

src/distilabel/steps/tasks/text_generation.py

@@ -62,14 +62,10 @@ def format_input(self, input: Dict[str, Any]) -> ChatType:
         is the first interaction from the user within a conversation."""
 
         if is_openai_format(input["instruction"]):
-            warnings.warn(
+            raise ValueError(
                 "Providing `instruction` formatted as an OpenAI chat / conversation is"
-                " about to be deprecated in `distilabel v1.2.0`, please make sure to use"
-                " `ChatTextGeneration` with `messages` as input instead.",
-                DeprecationWarning,
-                stacklevel=2,
+                " deprecated, you should use `ChatGeneration` with `messages` as input instead.",
             )
-            return input["instruction"]
 
         if not isinstance(input["instruction"], str):
             raise ValueError(

tests/unit/steps/tasks/test_text_generation.py

@@ -53,6 +53,12 @@ def test_format_input_errors(self) -> None:
             name="task", llm=llm, pipeline=pipeline, use_system_prompt=True
         )
 
+        with pytest.raises(
+            ValueError,
+            match=r"Providing \`instruction\` formatted as an OpenAI chat / conversation is deprecated",
+        ):
+            task.format_input({"instruction": [{"role": "user", "content": "test"}]})
+
         with pytest.raises(
             ValueError, match=r"Input \`instruction\` must be a string. Got: 1."
         ):
@@ -79,23 +85,6 @@ def test_process(self) -> None:
             }
         ]
 
-    def test_deprecation_warning(self) -> None:
-        pipeline = Pipeline(name="unit-test-pipeline")
-        llm = DummyLLM()
-        task = TextGeneration(name="task", llm=llm, pipeline=pipeline)
-
-        with pytest.warns(
-            DeprecationWarning,
-            match=r"Providing \`instruction\` formatted as an OpenAI chat \/ conversation is about to be deprecated in \`distilabel v1.2.0\`",
-        ):
-            task.format_input(
-                {
-                    "instruction": [
-                        {"role": "user", "content": "Tell me a joke."},
-                    ]
-                }
-            )
-
 
 class TestChatGeneration:
     def test_format_input(self) -> None: