Merge pull request #45 from TeskaLabs/Enhancement/Load-json-var-from-…

…file

Load variables from file.

asabiris/formatter/jinja/service.py

@@ -2,6 +2,8 @@
 import configparser
 
 import asab
+import pathlib
+import json
 import jinja2
 
 from ...exceptions import PathError
@@ -26,6 +28,44 @@ def __init__(self, app, service_name="JinjaService"):
 			self.Variables = {}
 
 		self.Environment = jinja2.Environment()
+		self._load_variables_from_json()
+
+	def _load_variables_from_json(self):
+		"""
+		Load variables from a JSON file specified in the 'jinja' section of the configuration.
+
+		This function attempts to read the path to a JSON file from the 'variables' key
+		under the 'jinja' section of the configuration. If the 'jinja' section or the
+		'variables' key is missing, the function returns without loading any variables.
+
+		If the specified JSON file is found, it reads and updates the internal variables
+		with the contents of the file. If the file is not found, cannot be read, or contains
+		invalid JSON, a warning is logged and the function returns without updating variables.
+
+		Overwrites any existing variables from the configuration file with the same keys.
+		"""
+		try:
+			json_path_str = asab.Config.get('jinja', 'variables')
+		except (configparser.NoSectionError, configparser.NoOptionError):
+			return
+
+		json_path = pathlib.Path(json_path_str)
+		if not json_path.is_file():
+			L.warning("JSON file specified '{}' in configuration does not exist.".format(json_path))
+			return
+
+		try:
+			with open(json_path, 'r') as json_file:
+				json_data = json.load(json_file)
+		except IOError as io_err:
+			L.warning("Failed to read JSON file '{}': {}".format(json_path, io_err))
+			return
+		except json.JSONDecodeError as json_err:
+			L.warning("Invalid JSON format in file '{}': {}".format(json_path, json_err))
+			return
+
+		self.Variables.update(json_data)
+		L.debug("Variables successfully loaded from JSON file '{}'.".format(json_path))
 
 
 	async def format(self, template_path, template_params):

test/test_loading_variables_from_file.py

@@ -0,0 +1,123 @@
+import unittest
+from unittest.mock import patch, MagicMock, mock_open
+from asabiris.formatter.jinja.service import JinjaFormatterService
+
+
+class TestJinjaFormatterService(unittest.TestCase):
+    """
+    Unit tests for the JinjaFormatterService class method _load_variables_from_json.
+    """
+
+    @patch('builtins.open', new_callable=mock_open, read_data='{"key": "value"}')
+    @patch('pathlib.Path.is_file')
+    @patch('asabiris.formatter.jinja.service.asab.Config.get')
+    def test_successful_json_load(self, mock_config_get, mock_is_file, _):
+        """
+        Test loading variables from a valid JSON file.
+        Ensures that variables are correctly loaded and updated.
+        """
+        mock_config_get.return_value = 'valid.json'
+        mock_is_file.return_value = True
+        mock_app = MagicMock()
+        service = JinjaFormatterService(mock_app)
+        service._load_variables_from_json()
+        self.assertEqual(service.Variables, {"key": "value"})
+
+    @patch('builtins.open', new_callable=mock_open, read_data='Not a JSON')
+    @patch('pathlib.Path.is_file')
+    @patch('asabiris.formatter.jinja.service.asab.Config.get')
+    def test_invalid_json_format(self, mock_config_get, mock_is_file, _):
+        """
+        Test behavior when the JSON file is not properly formatted.
+        Ensures that the method handles invalid JSON gracefully.
+        """
+        mock_config_get.return_value = 'invalid.json'
+        mock_is_file.return_value = True
+        mock_app = MagicMock()
+        service = JinjaFormatterService(mock_app)
+        service._load_variables_from_json()
+        self.assertEqual(service.Variables, {})
+
+    @patch('builtins.open', mock_open(), create=True)
+    @patch('pathlib.Path.is_file')
+    @patch('asabiris.formatter.jinja.service.asab.Config.get')
+    def test_io_error_on_file_open(self, mock_config_get, mock_is_file):
+        """
+        Test the handling of IOError when opening the JSON file.
+        Ensures that the method handles file opening errors correctly.
+        """
+        mock_config_get.return_value = 'error.json'
+        mock_is_file.return_value = True
+        mock_open.side_effect = IOError("Failed to open file")
+        mock_app = MagicMock()
+        service = JinjaFormatterService(mock_app)
+        service._load_variables_from_json()
+        self.assertEqual(service.Variables, {})
+
+    @patch('builtins.open', new_callable=mock_open, read_data='{"key": "new_value"}')
+    @patch('pathlib.Path.is_file')
+    @patch('asabiris.formatter.jinja.service.asab.Config.get')
+    def test_update_existing_variables(self, mock_config_get, mock_is_file, _):
+        """
+        Test updating existing variables with new values from the JSON file.
+        Ensures that existing variables are correctly updated.
+        """
+        mock_config_get.return_value = 'update.json'
+        mock_is_file.return_value = True
+        mock_app = MagicMock()
+        service = JinjaFormatterService(mock_app)
+        service.Variables = {"key": "old_value"}
+        service._load_variables_from_json()
+        self.assertEqual(service.Variables, {"key": "new_value"})
+
+    @patch('builtins.open', new_callable=mock_open, read_data='{"new_key": "value"}')
+    @patch('pathlib.Path.is_file')
+    @patch('asabiris.formatter.jinja.service.asab.Config.get')
+    def test_add_new_variables(self, mock_config_get, mock_is_file, _):
+        """
+        Test adding new variables from the JSON file to existing ones.
+        Ensures that new variables are correctly added.
+        """
+        mock_config_get.return_value = 'add.json'
+        mock_is_file.return_value = True
+        mock_app = MagicMock()
+        service = JinjaFormatterService(mock_app)
+        service.Variables = {"existing_key": "existing_value"}
+        service._load_variables_from_json()
+        self.assertEqual(service.Variables, {"existing_key": "existing_value", "new_key": "value"})
+
+    @patch('builtins.open', new_callable=mock_open, read_data='{}')
+    @patch('pathlib.Path.is_file')
+    @patch('asabiris.formatter.jinja.service.asab.Config.get')
+    def test_empty_json_file(self, mock_config_get, mock_is_file, _):
+        """
+        Test behavior when the JSON file is empty.
+        Ensures that the method handles empty JSON files correctly.
+        """
+        mock_config_get.return_value = 'empty.json'
+        mock_is_file.return_value = True
+        mock_app = MagicMock()
+        service = JinjaFormatterService(mock_app)
+        service._load_variables_from_json()
+        self.assertEqual(service.Variables, {})
+
+
+    @patch('builtins.open', new_callable=mock_open, read_data='{"complex": {"nested": {"key": ["value1", {"subkey": "subvalue"}]}}}')
+    @patch('pathlib.Path.is_file')
+    @patch('asabiris.formatter.jinja.service.asab.Config.get')
+    def test_complex_nested_json_structure(self, mock_config_get, mock_is_file, _):
+        """
+        Test loading variables from a JSON file with a complex nested structure.
+        This test is designed to challenge the method's ability to handle complex JSON structures.
+        """
+        mock_config_get.return_value = 'complex.json'
+        mock_is_file.return_value = True
+        mock_app = MagicMock()
+        service = JinjaFormatterService(mock_app)
+        service._load_variables_from_json()
+        expected_structure = {"complex": {"nested": {"key": ["value1", {"subkey": "subvalue"}]}}}
+        self.assertEqual(service.Variables, expected_structure)
+
+
+if __name__ == '__main__':
+    unittest.main()