Update resource provider string representation

docs/main/changelog.rst

@@ -12,6 +12,7 @@ Development version
 - Add ``.provides`` attribute to ``Singleton`` and its subclasses.
   It's a consistency change to make ``Singleton`` match ``Callable``
   and ``Factory`` interfaces.
+- Update string representation of ``Resource`` provider.
 
 4.13.2
 ------

src/dependency_injector/providers.pyx

@@ -2992,11 +2992,12 @@ cdef class Resource(Provider):
 
         return copied
 
-    def __repr__(self):
+    def __str__(self):
-        return (
+        """Return string representation of provider.
-            f'{self.__class__.__name__}({self.__initializer}, '
+
-            f'initialized={self.__initialized})'
+        :rtype: str
-        )
+        """
+        return represent_provider(provider=self, provides=self.__initializer)
 
     @property
     def args(self):

tests/unit/providers/test_resource_py35.py

@@ -337,9 +337,9 @@ class ResourceTests(unittest.TestCase):
 
         self.assertEqual(
             repr(provider),
-            'Resource({0}, initialized={1})'.format(
+            '<dependency_injector.providers.Resource({0}) at {1}>'.format(
-                init_fn,
+                repr(init_fn),
-                provider.initialized,
+                hex(id(provider)),
             )
         )