Add tests to check permission-restricted broadcast pages

Some pages should only be shown to users who have permission to send or
approve broadcasts. This commit adds a test to ensure that this is true,
and that we don’t accidentally regress the checks for this permission.

tests/app/main/views/test_broadcast.py

@@ -75,6 +75,63 @@ def test_broadcast_pages_403_without_permission(
     )
 
 
+@pytest.mark.parametrize('endpoint, extra_args, expected_get_status, expected_post_status', (
+    (
+        '.broadcast',
+        {'template_id': sample_uuid},
+        403, 405,
+    ),
+    (
+        '.preview_broadcast_areas', {'broadcast_message_id': sample_uuid},
+        403, 405,
+    ),
+    (
+        '.choose_broadcast_library', {'broadcast_message_id': sample_uuid},
+        403, 405,
+    ),
+    (
+        '.choose_broadcast_area', {'broadcast_message_id': sample_uuid, 'library_slug': 'countries'},
+        403, 403,
+    ),
+    (
+        '.remove_broadcast_area', {'broadcast_message_id': sample_uuid, 'area_slug': 'england'},
+        403, 405,
+    ),
+    (
+        '.preview_broadcast_message', {'broadcast_message_id': sample_uuid},
+        403, 403,
+    ),
+    (
+        '.cancel_broadcast_message', {'broadcast_message_id': sample_uuid},
+        403, 403,
+    ),
+))
+def test_broadcast_pages_403_for_user_without_permission(
+    mocker,
+    client_request,
+    service_one,
+    active_user_view_permissions,
+    endpoint,
+    extra_args,
+    expected_get_status,
+    expected_post_status,
+):
+    service_one['permissions'] += ['broadcast']
+    mocker.patch('app.user_api_client.get_user', return_value=active_user_view_permissions)
+    client_request.get(
+        endpoint,
+        service_id=SERVICE_ONE_ID,
+        _expected_status=expected_get_status,
+        **extra_args
+    )
+    client_request.post(
+        endpoint,
+        service_id=SERVICE_ONE_ID,
+        _expected_status=expected_post_status,
+        **extra_args
+    )
+
+
 def test_dashboard_redirects_to_broadcast_dashboard(
     client_request,
     service_one,
@@ -94,6 +151,7 @@ def test_dashboard_redirects_to_broadcast_dashboard(
 def test_empty_broadcast_dashboard(
     client_request,
     service_one,
+    active_user_view_permissions,
     mock_get_no_broadcast_messages,
     mock_get_service_templates_when_no_templates_exist,
 ):
@@ -157,6 +215,7 @@ def test_broadcast_dashboard(
 def test_broadcast_dashboard_json(
     logged_in_client,
     service_one,
+    active_user_view_permissions,
     mock_get_broadcast_messages,
 ):
     service_one['permissions'] += ['broadcast']