Taniwha/bb 2497/ironwood fix root block (#74)

* Handle invalid key errors for root_block

Catch InvalidKeyError as per opaque_keys docs. This is for BB-2497.

* Handle invalid key errors for course_key

While implementing the fix for root_block, it was found that course_key
handling could run into the same problems. This is a preventative fix.

* Correctly order imports

* Be more verbose for invalid keys

* Bump version and update CHANGELOG

* Correct invalid course key error message

* Be more informative when student is not enrolled

As per request by @Agrendalath, also, it just makes sense to do so.

* Fix line length issue

CHANGELOG.rst

@@ -14,6 +14,11 @@ Change Log
 Unreleased
 ~~~~~~~~~~
 
+[2.2.1] - 2020-06-05
+~~~~~~~~~~~~~~~~~~~~
+
+* Fix handling of invalid keys.
+
 [2.1.3] - 2020-05-08
 ~~~~~~~~~~~~~~~~~~~~
 

completion_aggregator/__init__.py

@@ -4,6 +4,6 @@
 
 from __future__ import absolute_import, unicode_literals
 
-__version__ = '2.2.0'
+__version__ = '2.2.1'
 
 default_app_config = 'completion_aggregator.apps.CompletionAggregatorAppConfig'  # pylint: disable=invalid-name

completion_aggregator/api/v1/views.py

@@ -8,6 +8,7 @@
 from collections import defaultdict
 
 import waffle
+from opaque_keys import InvalidKeyError
 from opaque_keys.edx.keys import CourseKey, UsageKey
 from rest_framework.exceptions import NotFound, ParseError
 from rest_framework.views import APIView
@@ -361,7 +362,10 @@ def _parse_aggregator(self, course_key, params=None):
         """
         Handles fetching and return aggregator data, regardless of the method used
         """
-        course_key = CourseKey.from_string(course_key)
+        try:
+            course_key = CourseKey.from_string(course_key)
+        except InvalidKeyError:
+            raise NotFound("Invalid course key: '{}'.".format(course_key))
         paginator = self.pagination_class()  # pylint: disable=not-callable
         requested_fields = self.get_requested_fields()
 
@@ -377,7 +381,10 @@ def _parse_aggregator(self, course_key, params=None):
         else:
             if not UserEnrollments(self.user).is_enrolled(course_key):
                 # Return 404 if effective user does not have an active enrollment in the requested course
-                raise NotFound()
+                raise NotFound(
+                    "User '{user}' does not have an active enrollment in course '{course_key}'."
+                    .format(user=self.user, course_key=course_key)
+                )
             is_stale = StaleCompletion.objects.filter(
                 username=self.user.username,
                 course_key=course_key,
@@ -395,7 +402,10 @@ def _parse_aggregator(self, course_key, params=None):
 
         root_block = params.get('root_block')
         if root_block:
-            root_block = UsageKey.from_string(root_block).map_into_course(course_key)
+            try:
+                root_block = UsageKey.from_string(root_block).map_into_course(course_key)
+            except InvalidKeyError:
+                raise NotFound("Invalid block key: '{}'.".format(root_block))
 
         if is_stale and waffle.flag_is_active(self.request, WAFFLE_AGGREGATE_STALE_FROM_SCRATCH):
             aggregator_queryset = []
@@ -541,7 +551,10 @@ def get(self, request, course_key):
         """
         Handler for GET requests
         """
-        course_key = CourseKey.from_string(course_key)
+        try:
+            course_key = CourseKey.from_string(course_key)
+        except InvalidKeyError:
+            raise NotFound("Invalid course key: '{}'.".format(course_key))
         requested_fields = self.get_requested_fields()
         roles_to_exclude = self.request.query_params.get('exclude_roles', '').split(',')
         cohort_filter = self._parse_cohort_filter(