feat: add test for levy's dpo case

tests/prompt_strategies/test_dpo_chat_templates.py

@@ -86,6 +86,13 @@ def fixture_llama3_tokenizer():
     return tokenizer
 
 
+@pytest.fixture(name="phi3_tokenizer")
+def fixture_phi3_tokenizer():
+    tokenizer = AutoTokenizer.from_pretrained("microsoft/Phi-3-medium-128k-instruct")
+
+    return tokenizer
+
+
 class TestAssistantDPOChatTemplateLlama3:
     """
     Test class for assistant style datasets with llama-3 prompts using the chat_template strategy.
@@ -152,5 +159,36 @@ class TestAssistantDPOChatTemplateLlama3:
         assert result["rejected"] == "party on<|eot_id|>"
 
 
+class TestAssistantDPOChatTemplatePhi3:
+    """
+    Test class for assistant style datasets with phi-3 prompts using the tokenizer's chat_template strategy.
+    """
+
+    def test_phi3_defaults(self, phi3_tokenizer, assistant_dataset):
+        # pylint: disable=duplicate-code
+        transform_fn = default(
+            DictDefault(
+                {
+                    "chat_template": "tokenizer_default",
+                    "datasets": [
+                        {
+                            "type": "chat_template",
+                            "chat_template": "tokenizer_default",
+                        }
+                    ],
+                }
+            )
+        )
+        result = transform_fn(assistant_dataset[0], tokenizer=phi3_tokenizer)
+        assert result["prompt"] == (
+            "<|user|>\nhello<|end|>\n"
+            + "<|assistant|>\nhello<|end|>\n"
+            + "<|user|>\ngoodbye<|end|>\n"
+            + "<|assistant|>\n"
+        )
+        assert result["chosen"] == "goodbye<|end|>"
+        assert result["rejected"] == "party on<|end|>"
+
+
 if __name__ == "__main__":
     unittest.main()