better handling and logging of empty sharegpt turns (#603)

tests/test_prompt_tokenizers.py

@@ -3,7 +3,9 @@ import json
 import logging
 import unittest
 from pathlib import Path
+from typing import Optional
 
+import pytest
 from transformers import AutoTokenizer, LlamaTokenizer
 
 from axolotl.prompt_strategies.alpaca_chat import NoSystemPrompter
@@ -29,6 +31,12 @@ class TestPromptTokenizationStrategies(unittest.TestCase):
     Test class for prompt tokenization strategies.
     """
 
+    _caplog: Optional[pytest.LogCaptureFixture] = None
+
+    @pytest.fixture(autouse=True)
+    def inject_fixtures(self, caplog):
+        self._caplog = caplog
+
     def setUp(self) -> None:
         # pylint: disable=duplicate-code
         self.tokenizer = AutoTokenizer.from_pretrained("huggyllama/llama-7b")
@@ -64,6 +72,24 @@ class TestPromptTokenizationStrategies(unittest.TestCase):
             self.assertEqual(len(example[fields]), len(tokenized_conversation[fields]))
             self.assertEqual(example[fields], tokenized_conversation[fields])
 
+    def test_sharegpt_warnings_integration(self):
+        with open(
+            Path(__file__).parent / "fixtures/conversation.missingturns.json",
+            encoding="utf-8",
+        ) as fin:
+            data = fin.read()
+            conversation = json.loads(data)
+        prompter = ShareGPTPrompter("chat")
+        strat = ShareGPTPromptTokenizingStrategy(
+            prompter,
+            self.tokenizer,
+            False,
+            2048,
+        )
+        with self._caplog.at_level(logging.WARNING):
+            strat.tokenize_prompt(conversation)
+            assert "assistant turn has empty text" in self._caplog.records[1].message
+
     def test_no_sys_prompt(self):
         """
         tests the interface between the user and assistant parts