Add __resolved__ property. Closes ionelmc#41.

Author: ionelmc

src/lazy_object_proxy/cext.c

@@ -1080,6 +1080,18 @@ static int Proxy_set_annotations(ProxyObject *self,
 
 /* ------------------------------------------------------------------------- */
 
+static PyObject *Proxy_get_resolved(
+        ProxyObject *self)
+{
+    PyObject *result;
+
+    result = self->wrapped ? Py_True : Py_False;
+    Py_INCREF(result);
+    return result;
+}
+
+/* ------------------------------------------------------------------------- */
+
 static PyObject *Proxy_get_wrapped(
         ProxyObject *self)
 {
@@ -1444,6 +1456,8 @@ static PyGetSetDef Proxy_getset[] = {
                             (setter)Proxy_set_wrapped, 0 },
     { "__factory__",        (getter)Proxy_get_factory,
                             (setter)Proxy_set_factory, 0 },
+    { "__resolved__",       (getter)Proxy_get_resolved,
+                            NULL, 0 },
     { NULL },
 };
 

src/lazy_object_proxy/simple.py

@@ -71,6 +71,10 @@ class Proxy(with_metaclass(_ProxyMetaType)):
     def __init__(self, factory):
         self.__dict__['__factory__'] = factory
 
+    @property
+    def __resolved__(self):
+        return '__wrapped__' in self.__dict__
+
     @cached_property
     def __wrapped__(self):
         self = self.__dict__

src/lazy_object_proxy/slots.py

@@ -72,6 +72,7 @@ class Proxy(with_metaclass(_ProxyMetaType)):
 
     * ``__factory__`` is the callback that "materializes" the object we proxy to.
     * ``__target__`` will contain the object we proxy to, once it's "materialized".
+    * ``__resolved__`` is a boolean, `True` if factory was called.
     * ``__wrapped__`` is a property that does either:
 
       * return ``__target__`` if it's set.
@@ -83,6 +84,15 @@ class Proxy(with_metaclass(_ProxyMetaType)):
     def __init__(self, factory):
         object.__setattr__(self, '__factory__', factory)
 
+    @property
+    def __resolved__(self, __getattr__=object.__getattribute__):
+        try:
+            __getattr__(self, '__target__')
+        except AttributeError:
+            return False
+        else:
+            return True
+
     @property
     def __wrapped__(self, __getattr__=object.__getattribute__, __setattr__=object.__setattr__,
                     __delattr__=object.__delattr__):

tests/test_lazy_object_proxy.py

@@ -1846,6 +1846,7 @@ def test_proto(benchmark, prototype):
 def test_subclassing_with_local_attr(lop):
     class Foo:
         pass
+
     called = []
 
     class LazyProxy(lop.Proxy):
@@ -1897,3 +1898,22 @@ def test_fspath(lop):
 
 def test_fspath_method(lop):
     assert lop.Proxy(FSPathMock).__fspath__() == '/tmp'
+
+
+def test_resolved_new(lop):
+    obj = lop.Proxy.__new__(lop.Proxy)
+    assert obj.__resolved__ is False
+
+
+def test_resolved(lop):
+    obj = lop.Proxy(lambda: None)
+    assert obj.__resolved__ is False
+    assert obj.__wrapped__ is None
+    assert obj.__resolved__ is True
+
+
+def test_resolved_str(lop):
+    obj = lop.Proxy(lambda: None)
+    assert obj.__resolved__ is False
+    str(obj)
+    assert obj.__resolved__ is True