From 7cebb873df947a96a02cb38f7cc465f8c5d040b5 Mon Sep 17 00:00:00 2001
From: Chris Dodge <cdodge@edx.org>
Date: Fri, 14 Jun 2013 16:35:21 -0400
Subject: [PATCH] allow for an optional throw_on_not_found on
 contentstore().find() so we can clean up caller logic in the tests

---
 .../contentstore/tests/test_contentstore.py   | 52 +++++--------------
 .../lib/xmodule/xmodule/contentstore/mongo.py |  7 ++-
 2 files changed, 19 insertions(+), 40 deletions(-)

diff --git a/cms/djangoapps/contentstore/tests/test_contentstore.py b/cms/djangoapps/contentstore/tests/test_contentstore.py
index 5b829781c4..a503f22c26 100644
--- a/cms/djangoapps/contentstore/tests/test_contentstore.py
+++ b/cms/djangoapps/contentstore/tests/test_contentstore.py
@@ -435,14 +435,12 @@ class ContentStoreToyCourseTest(ModuleStoreTestCase):
 
         import_from_xml(module_store, 'common/test/data/', ['full'], static_content_store=content_store)
 
-        content = None
-        try:
-            location = StaticContent.get_location_from_path('/c4x/edX/full/asset/circuits_duality.gif')
-            content = content_store.find(location)
-        except NotFoundError:
-            pass
-
+        # look up original (and thumbnail) in content store, should be there after import
+        location = StaticContent.get_location_from_path('/c4x/edX/full/asset/circuits_duality.gif')
+        content = content_store.find(location, throw_on_not_found=False)
+        thumbnail_location = content.thumbnail_location
         self.assertIsNotNone(content)
+        self.assertIsNotNone(thumbnail_location)
 
         # go through the website to do the delete, since the soft-delete logic is in the view
 
@@ -453,26 +451,14 @@ class ContentStoreToyCourseTest(ModuleStoreTestCase):
         asset_location = StaticContent.get_location_from_path('/c4x/edX/full/asset/circuits_duality.gif')
 
         # now try to find it in store, but they should not be there any longer
-        content = None
-        thumbnail = None
-        try:
-            content = content_store.find(asset_location)
-            thumbnail = trash_store.find(content.thumbnail_location)
-        except NotFoundError:
-            pass
+        content = content_store.find(asset_location, throw_on_not_found=False)
+        thumbnail = content_store.find(thumbnail_location, throw_on_not_found=False)
         self.assertIsNone(content)
         self.assertIsNone(thumbnail)
 
-        # now try to find it and the thumbnail in trashcan
-        content = None
-        thumbnail = None
-        try:
-            content = trash_store.find(asset_location)
-            thumbnail = trash_store.find(content.thumbnail_location)
-        except NotFoundError:
-            pass
-
-        # should be in trashcan
+        # now try to find it and the thumbnail in trashcan - should be in there
+        content = trash_store.find(asset_location, throw_on_not_found=False)
+        thumbnail = trash_store.find(thumbnail_location, throw_on_not_found=False)
         self.assertIsNotNone(content)
         self.assertIsNotNone(thumbnail)
 
@@ -480,13 +466,8 @@ class ContentStoreToyCourseTest(ModuleStoreTestCase):
         restore_asset_from_trashcan('/c4x/edX/full/asset/circuits_duality.gif')
 
         # now try to find it in courseware store, and they should be back after restore
-        content = None
-        thumbnail = None
-        try:
-            content = content_store.find(asset_location)
-            thumbnail = trash_store.find(content.thumbnail_location)
-        except NotFoundError:
-            pass
+        content = content_store.find(asset_location, throw_on_not_found=False)
+        thumbnail = content_store.find(thumbnail_location, throw_on_not_found=False)
         self.assertIsNotNone(content)
         self.assertIsNotNone(thumbnail)
 
@@ -502,13 +483,8 @@ class ContentStoreToyCourseTest(ModuleStoreTestCase):
 
         course_location = CourseDescriptor.id_to_location('edX/full/6.002_Spring_2012')
 
-        content = None
-        try:
-            location = StaticContent.get_location_from_path('/c4x/edX/full/asset/circuits_duality.gif')
-            content = content_store.find(location)
-        except NotFoundError:
-            pass
-
+        location = StaticContent.get_location_from_path('/c4x/edX/full/asset/circuits_duality.gif')
+        content = content_store.find(location, throw_on_not_found=False)
         self.assertIsNotNone(content)
 
         # go through the website to do the delete, since the soft-delete logic is in the view
diff --git a/common/lib/xmodule/xmodule/contentstore/mongo.py b/common/lib/xmodule/xmodule/contentstore/mongo.py
index 7d96e132ee..fa0fc95181 100644
--- a/common/lib/xmodule/xmodule/contentstore/mongo.py
+++ b/common/lib/xmodule/xmodule/contentstore/mongo.py
@@ -43,7 +43,7 @@ class MongoContentStore(ContentStore):
         if self.fs.exists({"_id": id}):
             self.fs.delete(id)
 
-    def find(self, location):
+    def find(self, location, throw_on_not_found=True):
         id = StaticContent.get_id_from_location(location)
         try:
             with self.fs.get(id) as fp:
@@ -52,7 +52,10 @@ class MongoContentStore(ContentStore):
                                      thumbnail_location=fp.thumbnail_location if hasattr(fp, 'thumbnail_location') else None,
                                      import_path=fp.import_path if hasattr(fp, 'import_path') else None)
         except NoFile:
-            raise NotFoundError()
+            if throw_on_not_found:
+                raise NotFoundError()
+            else:
+                return None
 
     def export(self, location, output_directory):
         content = self.find(location)