fix(smolagents): add test for issue #1972

tests/test_issue_1972.py

@@ -0,0 +1,28 @@
+from unittest.mock import MagicMock, patch
+
+from smolagents.models import LiteLLMModel
+
+
+def test_issue_1972():
+    mock_litellm = MagicMock()
+    mock_response = MagicMock()
+    mock_response.choices = [MagicMock()]
+    mock_response.choices[0].message.role = "assistant"
+    mock_response.choices[0].message.content = "FOO.BAR"
+    mock_response.choices[0].message.tool_calls = None
+    mock_response.usage.prompt_tokens = 10
+    mock_response.usage.completion_tokens = 5
+    mock_litellm.completion.return_value = mock_response
+
+    messages = [
+        {"role": "system", "content": "When you say anything Start with 'FOO'"},
+        {"role": "system", "content": "When you say anything End with 'BAR'"},
+        {"role": "user", "content": "Just say '.'"},
+    ]
+
+    with patch("smolagents.models.LiteLLMModel.create_client", return_value=mock_litellm):
+        model = LiteLLMModel(model_id="gemini/gemini-2.5-flash", api_key="test_api_key")
+        response = model(messages)
+
+    assert response.content == "FOO.BAR"
+    assert mock_litellm.completion.call_count == 1