From 45751322b8985d43ad3e61ea93d4370a3da65857 Mon Sep 17 00:00:00 2001
From: Kurt Steinkraus <kurt@steinkraus.us>
Date: Sun, 7 Jul 2013 20:47:04 -0700
Subject: [PATCH] Validates python type of ObjectGraph.provide() arg.

---
 TODO                         |  5 ++---
 pinject/object_graph.py      |  7 +++++++
 pinject/object_graph_test.py | 17 +++++++++++++++++
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/TODO b/TODO
index 7ff7a62..878f67e 100644
--- a/TODO
+++ b/TODO
@@ -1,8 +1,5 @@
 TODO:
-- validate python types of all input
 - allow binding specs to declare required bindings
-- standard tests for scopes (reentrant? thread-safe?), annotations (eq?
-     hash?), etc.
 - describe features specifically omitted, e.g.,
   - field injection
   - circular injection
@@ -10,6 +7,8 @@ TODO:
 - figure out whether/how Pinject works with inheritance
 
 Maybe TODO:
+- standard tests for scopes (reentrant? thread-safe?), annotations (eq?
+     hash?), etc.
 - change default scope back to prototype?
 - eager singletons
 - allow field injection
diff --git a/pinject/object_graph.py b/pinject/object_graph.py
index 4f33dfe..90b22f5 100644
--- a/pinject/object_graph.py
+++ b/pinject/object_graph.py
@@ -148,6 +148,12 @@ def new_object_graph(
         use_short_stack_traces)
 
 
+def _verify_type(elt, required_type, arg_name):
+    if type(elt) != required_type:
+        raise errors.WrongArgTypeError(
+            arg_name, required_type.__name__, type(elt).__name__)
+
+
 def _verify_types(seq, required_type, arg_name):
     if not isinstance(seq, collections.Sequence):
         raise errors.WrongArgTypeError(
@@ -199,6 +205,7 @@ def provide(self, cls):
         Raises:
           Error: an instance of cls is not providable
         """
+        _verify_type(cls, types.TypeType, 'cls')
         if not self._is_injectable_fn(cls):
             provide_loc = locations.get_back_frame_loc()
             raise errors.NonExplicitlyBoundClassError(provide_loc, cls)
diff --git a/pinject/object_graph_test.py b/pinject/object_graph_test.py
index b2cf1b7..cbaacba 100644
--- a/pinject/object_graph_test.py
+++ b/pinject/object_graph_test.py
@@ -145,6 +145,16 @@ def test_raises_exception_if_is_scope_usable_from_scope_is_wrong_type(self):
                           is_scope_usable_from_scope=42)
 
 
+class VerifyTypeTest(unittest.TestCase):
+
+    def test_verifies_correct_type_ok(self):
+        object_graph._verify_type(types, types.ModuleType, 'unused')
+
+    def test_raises_exception_if_incorrect_type(self):
+        self.assertRaises(errors.WrongArgTypeError, object_graph._verify_type,
+                          'not-a-module', types.ModuleType, 'an-arg-name')
+
+
 class VerifyTypesTest(unittest.TestCase):
 
     def test_verifies_empty_sequence_ok(self):
@@ -540,6 +550,13 @@ def provide_foo(self):
         self.assertRaises(errors.InjectingNoneDisallowedError,
                           obj_graph.provide, SomeClass)
 
+    def test_raises_exception_if_trying_to_provide_nonclass(self):
+        class SomeClass(object):
+            pass
+        obj_graph = object_graph.new_object_graph(
+            modules=None, classes=[SomeClass])
+        self.assertRaises(errors.WrongArgTypeError, obj_graph.provide, 42)
+
 
 class ObjectGraphWrapTest(unittest.TestCase):