Add data_logging/tests/test_core.py

data_logging/tests/test_core.py

@@ -0,0 +1,80 @@
+import json
+import os
+import tempfile
+from datetime import datetime
+import pytest
+
+import src.data_logging.core as core
+
+
+def _read_json_file(path):
+    with open(path, 'r', encoding='utf-8') as f:
+        return json.load(f)
+
+
+def test_log_data_creates_new_file():
+    with tempfile.TemporaryDirectory() as tmp:
+        output_path = os.path.join(tmp, 'log.json')
+        timestamp = datetime.utcnow()
+        core.log_data(timestamp, 25.3, 13.2)
+        # Move created log to tmp if implementation writes default, handle via os.replace if needed
+        if os.path.exists('output/environment_log.json'):
+            os.replace('output/environment_log.json', output_path)
+
+        assert os.path.isfile(output_path), 'Log file should be created'
+        data = _read_json_file(output_path)
+        assert isinstance(data, list)
+        entry = data[0]
+        assert set(entry.keys()) == {'timestamp', 'temperature', 'wind_speed'}
+        assert abs(entry['temperature'] - 25.3) < 1e-6
+        assert abs(entry['wind_speed'] - 13.2) < 1e-6
+        # ISO format validation
+        datetime.fromisoformat(entry['timestamp'])
+
+
+def test_log_data_appends_data():
+    with tempfile.NamedTemporaryFile(mode='w+', suffix='.json', delete=False) as tmp:
+        json.dump([], tmp)
+        tmp.flush()
+        ts1 = datetime.utcnow()
+        ts2 = datetime.utcnow()
+        core.log_data(ts1, 20.0, 5.0)
+        core.log_data(ts2, 30.0, 10.0)
+
+        # Move possibly default log
+        if os.path.exists('output/environment_log.json'):
+            os.replace('output/environment_log.json', tmp.name)
+
+        data = _read_json_file(tmp.name)
+        assert len(data) >= 2
+        last_record = data[-1]
+        assert isinstance(last_record['temperature'], (float, int))
+        assert isinstance(last_record['wind_speed'], (float, int))
+        datetime.fromisoformat(last_record['timestamp'])
+
+        os.unlink(tmp.name)
+
+
+def test_invalid_inputs_raise(tmp_path):
+    invalid_cases = [
+        (None, 25.0, 5.0),
+        (datetime.utcnow(), 'bad', 5.0),
+        (datetime.utcnow(), 25.0, 'wind'),
+    ]
+    for args in invalid_cases:
+        with pytest.raises((TypeError, ValueError)):
+            core.log_data(*args)
+
+
+def test_log_data_value_ranges(tmp_path):
+    # Temperature extreme but valid floats
+    ts = datetime.utcnow()
+    core.log_data(ts, -50.5, 0.0)
+    core.log_data(ts, 60.0, 200.0)
+    output_path = 'output/environment_log.json'
+    assert os.path.exists(output_path)
+    data = _read_json_file(output_path)
+    for e in data:
+        assert isinstance(e['temperature'], float)
+        assert isinstance(e['wind_speed'], float)
+        datetime.fromisoformat(e['timestamp'])