Support for mutable and immutable configurations

README.md

@@ -76,7 +76,17 @@ If the configuration file content is:
 
 the result will be `{'section1': {'key1': 'value1', 'key2': 'value2', 'number': 42, 'number2': 3.14, 'number3': -1, 'boolean': True, 'boolean2': False, 'null': None}, 'section2': {'hello': 'world'}, 'section3': {'key': 'value'}}`
 
+
+
+## Full documentation
+
+For the full documentation, see the Python docstrings.
+
 ## Changelog
+
+### Version 1.3.0
+- support for mutable and immutable configurations
+
 ### Version 1.2.1
 - Bug fix: `jeb_utils.exceptions.ConfigurationSyntaxError` has inherited from `SyntaxError`, which is semantically wrong. Now it is a normal exception and it inherits from `Exception`.
 

pyproject.toml

@@ -4,6 +4,6 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "config-parser"
-version = "1.2.1"
+version = "1.3.0"
 description = "A configuration file parser."
 license = "Apache-2.0"

src/config_parser/__init__.py

@@ -24,7 +24,8 @@ Modules:
 - serialize: A package including the serializers.
 '''
 
-from ._configuration import Configuration
+from ._configuration import *
+from ._configuration import __all__ as _configuration__all__
 from . import exceptions
 from . import json
 from . import ini
@@ -32,10 +33,10 @@ from . import parse
 from . import serialize
 
 __all__ = [
-    'Configuration',
     'exceptions',
     'json',
     'ini',
     'parse',
-    'serialize'
+    'serialize',
+    *_configuration__all__
 ]

src/config_parser/_configuration.py

@@ -13,49 +13,117 @@
 #  limitations under the License.
 
 import copy
+from types import FunctionType
+from typing import Any
 
 __all__ = [
-    'Configuration'
+    'Configuration',
+    'set_mutability',
+    'is_mutable',
 ]
 
 class Configuration:
-    def __init__(self, _config: dict = {}):
+    def __init__(self, _config: dict = {}, mutable: bool = True) -> None:
         '''A base class for configurations.'''
 
         self._config = copy.deepcopy(_config)
+        self._mutable = mutable
 
-    def __getattribute__(self, name):
+    def _check_mutability(self) -> None:
-        _config = super().__getattribute__('_config')
+        return self._mutable
+
+    def _mutate(self, func: FunctionType) -> FunctionType:
+        def wrapper(*args, **kwargs) -> Any:
+            if self._check_mutability():
+                return func(*args, **kwargs)
+            else:
+                raise TypeError('configuration is immutable')
+        return wrapper
+
+
+    def _set(self, name: str, value: str) -> None:
+        @self._mutate
+        def _set(name: str, value: str) -> None:
+            self._config[name] = value
+
+        _set(name, value)
+
+    def _delete(self, name: str) -> None:
+        @self._mutate
+        def _delete(name: str) -> None:
+            del self._config[name]
+
+        _delete(name)
+
+    def _get(self, name: str) -> str:
+        return self._config[name]
+
+    def __getattribute__(self, name: str):
         if name.startswith('_') or name in self.__dir__():
             return super().__getattribute__(name)
         else:
-            if name not in _config:
+            if name not in self._config:
                 raise AttributeError(f"'{self.__class__.__name__}' object has no attribute '{name}'")
-            return _config[name]
+            return self._get(name)
 
     def __setattr__(self, name, value):
         if name.startswith('_') or name in self.__dir__():
             super().__setattr__(name, value)
         else:
-            self._config[name] = value
+            self._set(name, value)
 
     def __delattr__(self, name):
         if name.startswith('_') or name in self.__dir__():
             super().__delattr__(name)
         else:
-            del self._config[name]
+            self._delete(name)
 
     def __setitem__(self, key, value):
-        self._config[key] = value
+        self._set(key, value)
 
     def __getitem__(self, key):
         return self._config[key]
 
     def __delitem__(self, key):
-        del self._config[key]
+        self._delete(key)
 
     def __iter__(self):
         return iter(self._config.items())
 
     def __contains__(self, item):
-        return item in self._config
+        return item in self._config
+
+def set_mutability(configuration: Configuration, mutable: bool, *, operate_on_original_object: bool = True) -> Configuration:
+    '''
+    Sets the mutability of a configuration.
+
+    :param configuration: The configuration object.
+    :type configuration: Configuration
+    :param mutable: The new mutability.
+    :type mutable: bool
+    :param operate_on_original_object: If ``True``, the mutability of the
+    original object will be set. If ``False``, the original object will be
+    unchanged. The new configuration will always be returned.
+    :type operate_on_original_object: bool
+
+    :return: The configuration object with the new mutability
+    :rtype: Configuration
+    '''
+
+    if not operate_on_original_object:
+        configuration = copy.deepcopy(configuration)
+
+    configuration._mutable = mutable
+    return configuration
+
+def is_mutable(configuration: Configuration) -> Configuration:
+    '''
+    Checks whether a configuration is mutable.
+
+    :param configuration: The configuration.
+    :type configuration: Configuration
+
+    :return: The mutability
+    :rtype: bool
+    '''
+    return configuration._mutable

tests/ini/test_ini.py

@@ -14,6 +14,7 @@
 
 from src.config_parser.ini import INIConfiguration, INIConfigurationSection
 from src.config_parser.exceptions import INISyntaxError
+from src.config_parser import set_mutability
 
 def test_generating():
     config = INIConfiguration()
@@ -71,4 +72,26 @@ l2=w2''')
     assert dict(INIConfiguration.from_string('''[section1]
 k1=v1
 k2=v2
-k4=v4''', default = default_configuration)) == {'section1': {'k1': 'v1', 'k2': 'v2', 'k3': 'v3', 'k4': 'v4'}, 'section2': {'l1': 'w1', 'l2': 'w2'}}
+k4=v4''', default = default_configuration)) == {'section1': {'k1': 'v1', 'k2': 'v2', 'k3': 'v3', 'k4': 'v4'}, 'section2': {'l1': 'w1', 'l2': 'w2'}}
+
+def test_mutability():
+    config = INIConfiguration(mutable=False)
+    try:
+        config.key = 'value'
+        assert False, 'Expected TypeError'
+    except TypeError:
+        pass
+
+    set_mutability(config, True)
+    assert config._mutable == True
+
+    config.key = 'value'
+
+    set_mutability(config, False)
+    assert config._mutable == False
+
+    try:
+        del config.key
+        assert False, 'Expected TypeError'
+    except TypeError:
+        pass

tests/json/test_json.py

@@ -14,6 +14,7 @@
 
 from src.config_parser.json import JSONConfiguration
 from src.config_parser.exceptions import JSONObjectSyntaxError, JSONValueSyntaxError, JSONStringSyntaxError, JSONArraySyntaxError, EscapeSequenceSyntaxError
+from src.config_parser import set_mutability
 
 def test_json_configuration():
     # Test valid JSON configuration parsing
@@ -220,4 +221,26 @@ def test_json_configuration():
         JSONConfiguration.from_string('')
         assert False, 'Excepted JSONValueSyntaxError'
     except JSONValueSyntaxError:
+        pass
+
+def test_mutability():
+    config = JSONConfiguration(mutable=False)
+    try:
+        config.key = 'value'
+        assert False, 'Expected TypeError'
+    except TypeError:
+        pass
+
+    set_mutability(config, True)
+    assert config._mutable == True
+
+    config.key = 'value'
+
+    set_mutability(config, False)
+    assert config._mutable == False
+
+    try:
+        del config.key
+        assert False, 'Expected TypeError'
+    except TypeError:
         pass

tests/test_configuration_class.py

@@ -12,7 +12,7 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 
-from src.config_parser import Configuration
+from src.config_parser import Configuration, set_mutability, is_mutable
 
 def test_crud_configuration_attrs():
     config = Configuration()
@@ -76,4 +76,37 @@ def test_crud_configuration_config_items():
         config.key1
         assert False, "AttributeError was not raised"
     except AttributeError:
-        pass
+        pass
+
+def test_mutability():
+    config = Configuration(mutable=False)
+    try:
+        config.key = 'value'
+        assert False, 'Expected TypeError'
+    except TypeError:
+        pass
+
+    set_mutability(config, True)
+    assert config._mutable == True
+
+    config.key = 'value'
+
+    set_mutability(config, False)
+    assert config._mutable == False
+    assert is_mutable(config) == False
+
+    try:
+        del config.key
+        assert False, 'Expected TypeError'
+    except TypeError:
+        pass
+
+
+    # Test operate_on_original_object parameter of set_mutability
+    config = Configuration(mutable = True)
+    set_mutability(config, False, operate_on_original_object = True)
+    assert is_mutable(config) == False
+
+    new_config = set_mutability(config, True, operate_on_original_object = False)
+    assert is_mutable(new_config) == True
+    assert is_mutable(config) == False