Use author_in_programming_group? policy for files & RfCs

* Allow all members of a programming group to list and solve RfCs
* Also adjust policy specs to respect programming groups

app/policies/application_policy.rb

@@ -50,9 +50,21 @@ class ApplicationPolicy
   private :teacher_in_study_group?
 
   def author_in_programming_group?
-    return false unless @record.contributor.programming_group?
+    if @record.respond_to? :contributor # e.g. submission
+      possible_programming_group = @record.contributor
 
-    @record.contributor.users.include?(@user)
+    elsif @record.respond_to? :context # e.g. file
+      possible_programming_group = @record.context.contributor
+
+    elsif @record.respond_to? :submission # e.g. request_for_comment
+      possible_programming_group = @record.submission.contributor
+    else
+      return false
+    end
+
+    return false unless possible_programming_group.programming_group?
+
+    possible_programming_group.users.include?(@user)
   end
   private :author_in_programming_group?
 

app/policies/code_ocean/file_policy.rb

@@ -38,7 +38,7 @@ module CodeOcean
       if @record.context.is_a?(Exercise)
         admin? || author?
       elsif @record.context.is_a?(Submission) && @record.context.exercise.allow_file_creation
-        author?
+        author? || author_in_programming_group?
       else
         no_one
       end

app/policies/request_for_comment_policy.rb

@@ -6,7 +6,7 @@ class RequestForCommentPolicy < ApplicationPolicy
   end
 
   def show?
-    admin? || author? || rfc_visibility
+    admin? || author? || author_in_programming_group? || rfc_visibility
   end
 
   def destroy?
@@ -14,11 +14,11 @@ class RequestForCommentPolicy < ApplicationPolicy
   end
 
   def mark_as_solved?
-    admin? || author?
+    admin? || author? || author_in_programming_group?
   end
 
   def set_thank_you_note?
-    admin? || author?
+    admin? || author? || author_in_programming_group?
   end
 
   def clear_question?