Add data_logging/tests/test_core.py

data_logging/tests/test_core.py

@@ -0,0 +1,33 @@
+import pytest
+from pathlib import Path
+import pandas as pd
+from data_logging import core
+
+@pytest.fixture
+def log_entries():
+    return [
+        core.LogEntry(timestamp="2024-06-01T12:00:00Z", water_level=1.23, ground_vibration=0.05, ai_label="steady"),
+        core.LogEntry(timestamp="2024-06-01T12:01:00Z", water_level=1.45, ground_vibration=0.07, ai_label="periodic"),
+    ]
+
+
+def test_export_to_csv_creates_file(tmp_path: Path, log_entries):
+    csv_path = core.export_to_csv(log_entries)
+    assert isinstance(csv_path, str)
+    output_path = Path(csv_path)
+    assert output_path.exists(), "CSV file was not created."
+
+
+def test_export_to_csv_content(log_entries, tmp_path: Path):
+    csv_path = core.export_to_csv(log_entries)
+    df = pd.read_csv(csv_path)
+    assert not df.empty
+    assert list(df.columns) == ["timestamp", "water_level", "ground_vibration", "ai_label"]
+    assert len(df) == 2
+    assert df.iloc[0]["ai_label"] == "steady"
+    assert pytest.approx(df.iloc[1]["water_level"], 0.001) == 1.45
+
+
+def test_export_to_csv_invalid_input_raises(tmp_path: Path):
+    with pytest.raises((TypeError, AttributeError)):
+        core.export_to_csv([{"timestamp": "bad", "wrong": 123}])