Begin extracting contexts into separate module

tests/test_main.py

@@ -1,18 +1,33 @@
-# test_main.py
-import pytest
-from click.testing import CliRunner
-from iottb.main import cli  # Adjust this import according to your project's structure
+from pathlib import Path
+from iottb.main import load_config
 
 
-@pytest.fixture
-def runner():
-    """Fixture to return a Click CliRunner instance."""
-    return CliRunner()
+class TestLoadConfig:
 
+    #  Loads configuration from an existing file
+    def test_loads_config_from_existing_file(self, mocker):
+        cfg_file = mocker.Mock()
+        cfg_file.is_file.return_value = True
+        mock_open = mocker.mock_open(
+            read_data=f'{{"DefaultDatabase": "test_db", "DefaultDatabasePath": "{Path.home()}/user"}}')
+        mocker.patch('builtins.open', mock_open)
 
-def test_debug_option(runner):
-    """Test if the debug mode sets the appropriate flag in the context."""
-    result = runner.invoke(cli, ['--debug'])
-    assert result.exit_code == 0
-    # If debug mode affects logging or other behavior, validate those:
-    assert 'DEBUG mode on' in result.output
+        result = load_config(cfg_file)
+
+        assert result == {"DefaultDatabase": "test_db", "DefaultDatabasePath": f"{Path.home()}/user"}
+        cfg_file.is_file.assert_called_once()
+        mock_open.assert_called_once_with(cfg_file, 'r')
+
+    #  File path is invalid or inaccessible
+    def test_file_path_invalid_or_inaccessible(self, mocker):
+        cfg_file = mocker.Mock()
+        cfg_file.is_file.return_value = False
+        mock_create_default_config = mocker.patch('iottb.main.create_default_config',
+                                                  return_value={"DefaultDatabase": "default_db",
+                                                                "DefaultDatabasePath": f"{Path.home()}/default"})
+
+        result = load_config(cfg_file)
+
+        assert result == {"DefaultDatabase": "default_db", "DefaultDatabasePath": f"{Path.home()}/default"}
+        cfg_file.is_file.assert_called_once()
+        mock_create_default_config.assert_called_once_with(cfg_file)