90: Renamed plugable.Abstract to ProxyTarget, which now subclasses from ReadOnly; updated unit tests

ipalib/plugable.py

@@ -43,7 +43,11 @@ class ReadOnly(object):
     __locked = False
 
     def __lock__(self):
-        assert self.__locked is False
+        """
+        Puts this instance into a read-only state, after which attempting to
+        set or delete an attribute will raise AttributeError.
+        """
+        assert self.__locked is False, '__lock__() can only be called once'
         self.__locked = True
 
     def __setattr__(self, name, value):
@@ -69,7 +73,7 @@ class ReadOnly(object):
         return object.__delattr__(self, name)
 
 
-class Abstract(object):
+class ProxyTarget(ReadOnly):
     __public__ = frozenset()
 
     @classmethod
@@ -86,6 +90,58 @@ class Abstract(object):
         )
 
 
+class Proxy(ReadOnly):
+    __slots__ = (
+        '__base',
+        '__target',
+        '__name_attr',
+        'name',
+        '__public__',
+    )
+
+    def __init__(self, base, target, name_attr='name'):
+        if not inspect.isclass(base):
+            raise TypeError('arg1 must be a class, got %r' % base)
+        if not isinstance(target, base):
+            raise ValueError('arg2 must be instance of arg1, got %r' % target)
+        self.__base = base
+        self.__target = target
+        self.__name_attr = name_attr
+        self.name = getattr(target, name_attr)
+        self.__public__ = base.__public__
+        assert type(self.__public__) is frozenset
+        check_identifier(self.name)
+        self.__lock__()
+
+    def __iter__(self):
+        for name in sorted(self.__public__):
+            yield name
+
+    def __getitem__(self, key):
+        if key in self.__public__:
+            return getattr(self.__target, key)
+        raise KeyError('no proxy attribute %r' % key)
+
+    def __getattr__(self, name):
+        if name in self.__public__:
+            return getattr(self.__target, name)
+        raise AttributeError('no proxy attribute %r' % name)
+
+    def __call__(self, *args, **kw):
+        return self['__call__'](*args, **kw)
+
+    def _clone(self, name_attr):
+        return self.__class__(self.__base, self.__target, name_attr)
+
+    def __repr__(self):
+        return '%s(%s, %r, %r)' % (
+            self.__class__.__name__,
+            self.__base.__name__,
+            self.__target,
+            self.__name_attr,
+        )
+
+
 class Plugin(object):
     """
     Base class for all plugins.
@@ -132,57 +188,7 @@ class Plugin(object):
 
 
 
-class Proxy(ReadOnly):
-    __slots__ = (
-        '__base',
-        '__target',
-        '__name_attr',
-        'name',
-        '__public__',
-    )
 
-    def __init__(self, base, target, name_attr='name'):
-        if not inspect.isclass(base):
-            raise TypeError('arg1 must be a class, got %r' % base)
-        if not isinstance(target, base):
-            raise ValueError('arg2 must be instance of arg1, got %r' % target)
-        self.__base = base
-        self.__target = target
-        self.__name_attr = name_attr
-        self.name = getattr(target, name_attr)
-        self.__public__ = base.__public__
-        assert type(self.__public__) is frozenset
-        check_identifier(self.name)
-        self.__lock__()
-
-
-    def __iter__(self):
-        for name in sorted(self.__public__):
-            yield name
-
-    def __getitem__(self, key):
-        if key in self.__public__:
-            return getattr(self.__target, key)
-        raise KeyError('no proxy attribute %r' % key)
-
-    def __getattr__(self, name):
-        if name in self.__public__:
-            return getattr(self.__target, name)
-        raise AttributeError('no proxy attribute %r' % name)
-
-    def __call__(self, *args, **kw):
-        return self['__call__'](*args, **kw)
-
-    def _clone(self, name_attr):
-        return self.__class__(self.__base, self.__target, name_attr)
-
-    def __repr__(self):
-        return '%s(%s, %r, %r)' % (
-            self.__class__.__name__,
-            self.__base.__name__,
-            self.__target,
-            self.__name_attr,
-        )
 
 
 class NameSpace(ReadOnly):

ipalib/tests/test_plugable.py

@@ -26,6 +26,33 @@ from tstutil import ClassChecker
 from ipalib import plugable, errors
 
 
+def test_valid_identifier():
+    """
+    Test the plugable.valid_identifier function.
+    """
+    f = plugable.check_identifier
+    okay = [
+        'user_add',
+        'stuff2junk',
+        'sixty9',
+    ]
+    nope = [
+        '_user_add',
+        '__user_add',
+        'user_add_',
+        'user_add__',
+        '_user_add_',
+        '__user_add__',
+        '60nine',
+    ]
+    for name in okay:
+        f(name)
+    for name in nope:
+        raises(errors.NameSpaceError, f, name)
+    for name in okay:
+        raises(errors.NameSpaceError, f, name.upper())
+
+
 class test_ReadOnly(ClassChecker):
     """
     Test the plugable.ReadOnly class
@@ -34,6 +61,7 @@ class test_ReadOnly(ClassChecker):
 
     def test_class(self):
         assert self.cls.__bases__ == (object,)
+        assert callable(self.cls.__lock__)
 
     def test_when_unlocked(self):
         """
@@ -73,79 +101,64 @@ class test_ReadOnly(ClassChecker):
         assert read_only(obj, 'an_attribute') == 'Hello world!'
 
 
+class test_ProxyTarget(ClassChecker):
+    """
+    Test the plugable.ProxyTarget class.
+    """
+    _cls = plugable.ProxyTarget
 
-def test_valid_identifier():
-    f = plugable.check_identifier
-    okay = [
-        'user_add',
-        'stuff2junk',
-        'sixty9',
-    ]
-    nope = [
-        '_user_add',
-        '__user_add',
-        'user_add_',
-        'user_add__',
-        '_user_add_',
-        '__user_add__',
-        '60nine',
-    ]
-    for name in okay:
-        f(name)
-    for name in nope:
-        raises(errors.NameSpaceError, f, name)
-    for name in okay:
-        raises(errors.NameSpaceError, f, name.upper())
+    def test_class(self):
+        assert self.cls.__bases__ == (plugable.ReadOnly,)
+        assert self.cls.implements(frozenset())
 
-
-def test_Abstract():
-    cls = plugable.Abstract
-
-    class example(cls):
+    def test_implements(self):
+        """
+        Test the implements() classmethod
+        """
+        class example(self.cls):
             __public__ = frozenset((
                 'some_method',
                 'some_property',
             ))
-
-    # Test using str:
-    assert example.implements('some_method')
-    assert not example.implements('another_method')
-
-    # Test using frozenset:
-    assert example.implements(frozenset(['some_method']))
-    assert not example.implements(
-        frozenset(['some_method', 'another_method'])
-    )
-
-    # Test using another object/class with __public__ frozenset:
-    assert example.implements(example)
-    assert example().implements(example)
-    assert example.implements(example())
-    assert example().implements(example())
-
-    class subset(cls):
-        __public__ = frozenset((
-            'some_property',
-        ))
-    assert example.implements(subset)
-    assert not subset.implements(example)
-
-    class superset(cls):
+        class superset(self.cls):
             __public__ = frozenset((
                 'some_method',
                 'some_property',
                 'another_property',
             ))
-    assert not example.implements(superset)
-    assert superset.implements(example)
-
+        class subset(self.cls):
+            __public__ = frozenset((
+                'some_property',
+            ))
         class any_object(object):
             __public__ = frozenset((
                 'some_method',
                 'some_property',
             ))
-    assert example.implements(any_object)
-    assert example.implements(any_object())
+
+        for ex in (example, example()):
+            # Test using str:
+            assert ex.implements('some_method')
+            assert not ex.implements('another_method')
+
+            # Test using frozenset:
+            assert ex.implements(frozenset(['some_method']))
+            assert not ex.implements(
+                frozenset(['some_method', 'another_method'])
+            )
+
+            # Test using another object/class with __public__ frozenset:
+            assert ex.implements(example)
+            assert ex.implements(example())
+
+            assert ex.implements(subset)
+            assert not subset.implements(ex)
+
+            assert not ex.implements(superset)
+            assert superset.implements(ex)
+
+            assert ex.implements(any_object)
+            assert ex.implements(any_object())
 
 
 def test_Plugin():