diff --git a/server/src/test/return_station_data/test_return_station_data.py b/server/src/test/return_station_data/test_return_station_data.py
new file mode 100644
index 0000000..a453d16
--- /dev/null
+++ b/server/src/test/return_station_data/test_return_station_data.py
@@ -0,0 +1,126 @@
+import unittest
+from unittest.mock import patch, MagicMock
+from functions.return_station_data.lambda_function import lambda_handler
+
+class TestLambdaFunction(unittest.TestCase):
+
+    @patch('src.functions.return_station_data.lambda_function.requests.get')
+    @patch('src.functions.return_station_data.lambda_function.xmltodict.parse')
+    def lambda_handler_returns_station_data_for_valid_stationCode(self, mock_parse, mock_get):
+        mock_response = MagicMock()
+        mock_response.text = '<xml>test</xml>'
+        mock_get.return_value = mock_response
+        mock_parse.return_value = {'station': 'data'}
+
+        event = {
+            'queryStringParameters': {'stationCode': 'test_station'}
+        }
+        context = {}
+
+        response = lambda_handler(event, context)
+
+        self.assertEqual(response['statusCode'], 200)
+        self.assertEqual(json.loads(response['body']), {'station': 'data'})
+
+    @patch('src.functions.return_station_data.lambda_function.requests.get')
+    def lambda_handler_returns_error_on_exception(self, mock_get):
+        mock_get.side_effect = Exception('Test exception')
+
+        event = {
+            'queryStringParameters': {'stationCode': 'test_station'}
+        }
+        context = {}
+
+        response = lambda_handler(event, context)
+
+        self.assertEqual(response['statusCode'], 500)
+        self.assertIn('error', json.loads(response['body']))
+
+    @patch('src.functions.return_station_data.lambda_function.requests.get')
+    def lambda_handler_returns_error_for_missing_stationCode(self, mock_get):
+        event = {
+            'queryStringParameters': {}
+        }
+        context = {}
+
+        response = lambda_handler(event, context)
+
+        self.assertEqual(response['statusCode'], 500)
+        self.assertIn('error', json.loads(response['body']))
+
+    @patch('src.functions.return_station_data.lambda_function.requests.get')
+    @patch('src.functions.return_station_data.lambda_function.xmltodict.parse')
+    def handles_non_xml_response(self, mock_parse, mock_get):
+        mock_response = MagicMock()
+        mock_response.text = 'Not XML'
+        mock_get.return_value = mock_response
+        mock_parse.side_effect = Exception('Failed to parse XML')
+
+        event = {'queryStringParameters': {'stationCode': 'DART'}}
+        context = {}
+
+        result = lambda_handler(event, context)
+
+        self.assertEqual(result['statusCode'], 500)
+        self.assertIn('error', json.loads(result['body']))
+
+    @patch('src.functions.return_station_data.lambda_function.requests.get')
+    def handles_empty_response(self, mock_get):
+        mock_response = MagicMock()
+        mock_response.text = ''
+        mock_get.return_value = mock_response
+
+        event = {'queryStringParameters': {'stationCode': 'DART'}}
+        context = {}
+
+        result = lambda_handler(event, context)
+
+        self.assertEqual(result['statusCode'], 500)
+        self.assertIn('error', json.loads(result['body']))
+
+    @patch('src.functions.return_station_data.lambda_function.requests.get')
+    @patch('src.functions.return_station_data.lambda_function.xmltodict.parse')
+    def handles_invalid_station_code(self, mock_parse, mock_get):
+        mock_response = MagicMock()
+        mock_response.text = '<root></root>'
+        mock_get.return_value = mock_response
+        mock_parse.return_value = {}
+
+        event = {'queryStringParameters': {'stationCode': 'INVALID'}}
+        context = {}
+
+        result = lambda_handler(event, context)
+
+        self.assertEqual(result['statusCode'], 200)
+        self.assertEqual(json.loads(result['body']), {})
+
+    @patch('src.functions.return_station_data.lambda_function.requests.get')
+    def lambda_handler_handles_timeout(self, mock_get):
+        mock_get.side_effect = TimeoutError('Request timed out')
+
+        event = {
+            'queryStringParameters': {'stationCode': 'test_station'}
+        }
+        context = {}
+
+        response = lambda_handler(event, context)
+
+        self.assertEqual(response['statusCode'], 504)
+        self.assertIn('error', json.loads(response['body']))
+
+    @patch('src.functions.return_station_data.lambda_function.requests.get')
+    def lambda_handler_handles_http_error(self, mock_get):
+        mock_response = MagicMock()
+        mock_response.status_code = 404
+        mock_response.raise_for_status.side_effect = Exception('HTTP error')
+        mock_get.return_value = mock_response
+
+        event = {
+            'queryStringParameters': {'stationCode': 'test_station'}
+        }
+        context = {}
+
+        response = lambda_handler(event, context)
+
+        self.assertEqual(response['statusCode'], 404)
+        self.assertIn('error', json.loads(response['body']))
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