Add new error for when a resource is found but cannot be accessed

atst/domain/exceptions.py

@@ -34,3 +34,12 @@ class UnauthenticatedError(Exception):
 
 class UploadError(Exception):
     pass
+
+
+class NoAccessError(Exception):
+    def __init__(self, resource_name):
+        self.resource_name = resource_name
+
+    @property
+    def message(self):
+        return "Route for {} cannot be accessed".format(self.resource_name)

atst/routes/errors.py

@@ -27,6 +27,7 @@ def make_error_pages(app):
     @app.errorhandler(exceptions.NotFoundError)
     @app.errorhandler(exceptions.UnauthorizedError)
     @app.errorhandler(PortfolioError)
+    @app.errorhandler(exceptions.NoAccessError)
     # pylint: disable=unused-variable
     def not_found(e):
         return handle_error(e)

atst/routes/portfolios/task_orders.py

@@ -5,7 +5,7 @@ from flask import g, redirect, render_template, url_for, request as http_request
 from . import portfolios_bp
 from atst.database import db
 from atst.domain.task_orders import TaskOrders, DD254s
-from atst.domain.exceptions import NotFoundError
+from atst.domain.exceptions import NotFoundError, NoAccessError
 from atst.domain.portfolios import Portfolios
 from atst.domain.authz import Authorization
 from atst.forms.officers import EditTaskOrderOfficersForm
@@ -93,7 +93,7 @@ def ko_review(portfolio_id, task_order_id):
             form=KOReviewForm(obj=task_order),
         )
     else:
-        raise NotFoundError("task_order")
+        raise NoAccessError("task_order")
 
 
 @portfolios_bp.route(