Refactor update creation api

This merge request does the following:

• Raise DRF errors rather than returning response to take advantage of the DRF exception handling mechanism
• Create serialisers for PUT request to simplify the code
• Improve validation checks in several places
• Fixes several issues in DRF infrastructure uses
• Fixes JSON fields handling
• Remove routes that do no fully qualify objects
• Implement a custom DRF exception handler that will allow to log errors
• Improve testing
• Improve permission management

beat/web/code/api.py

@@ -25,11 +25,12 @@
 #                                                                             #
 ###############################################################################
 
+from django.shortcuts import get_object_or_404
 
 from rest_framework import generics
 from rest_framework.response import Response
+from rest_framework import exceptions as drf_exceptions
 
-from ..common.responses import ForbiddenResponse
 from ..common.api import ShareView, RetrieveUpdateDestroyContributionView
 from ..common.serializers import DiffSerializer
 
@@ -54,34 +55,31 @@ class DiffView(generics.RetrieveAPIView):
 
     def get(self, request, author1, name1, version1, author2, name2, version2):
         # Retrieve the objects
-        try:
-            object1 = self.model.objects.get(
-                author__username__iexact=author1,
-                name__iexact=name1,
-                version=int(version1),
-            )
-        except Exception:
-            return Response("%s/%s/%s" % (author1, name1, version1), status=404)
-
-        try:
-            object2 = self.model.objects.get(
-                author__username__iexact=author2,
-                name__iexact=name2,
-                version=int(version2),
-            )
-        except Exception:
-            return Response("%s/%s/%s" % (author2, name2, version2), status=404)
+
+        object1 = get_object_or_404(
+            self.model,
+            author__username__iexact=author1,
+            name__iexact=name1,
+            version=int(version1),
+        )
+
+        object2 = get_object_or_404(
+            self.model,
+            author__username__iexact=author2,
+            name__iexact=name2,
+            version=int(version2),
+        )
 
         # Check that the user can access them
         has_access, open_source, _ = object1.accessibility_for(request.user)
         if not ((request.user == object1.author) or (has_access and open_source)):
-            return ForbiddenResponse(
+            raise drf_exceptions.PermissionDenied(
                 'You cannot access the source-code of "%s"' % object1.fullname()
             )
 
         has_access, open_source, _ = object2.accessibility_for(request.user)
         if not ((request.user == object2.author) or (has_access and open_source)):
-            return ForbiddenResponse(
+            raise drf_exceptions.PermissionDenied(
                 'You cannot access the source-code of "%s"' % object2.fullname()
             )