add test for save_data

Author: clavedeluna

tests/clients/test_utils_finetune.py

@@ -0,0 +1,21 @@
+import json
+import os
+
+from dspy.clients.utils_finetune import save_data
+
+
+def test_save_data_writes_jsonl_to_finetune_directory(tmp_path, monkeypatch):
+    monkeypatch.setenv("DSPY_FINETUNEDIR", str(tmp_path))
+    data = [
+        {"messages": [{"role": "user", "content": "What is 1 + 1?"}]},
+        {"messages": [{"role": "assistant", "content": "2"}]},
+    ]
+
+    file_path = save_data(data)
+
+    assert os.path.isabs(file_path)
+    assert os.path.dirname(file_path) == os.path.abspath(str(tmp_path))
+    assert file_path.endswith(".jsonl")
+
+    with open(file_path, encoding="utf-8") as f:
+        assert [json.loads(line) for line in f] == data