Add test case?

lib/galaxy/app_unittest_utils/galaxy_mock.py

@@ -441,7 +441,7 @@ class MockTemplateHelpers:
         pass
 
     def dumps(*kwargs):
-        return {}
+        return kwargs
 
     def js(*js_files):
         pass

test/unit/app/visualizations/plugins/test_VisualizationsRegistry.py

@@ -3,6 +3,7 @@ Test lib/galaxy/visualization/plugins/registry.
 """
 
 import os
+import re
 
 from galaxy.app_unittest_utils import galaxy_mock
 from galaxy.util import (
@@ -171,7 +172,8 @@ class TestVisualizationsRegistry(VisualizationsBase_TestCase):
         response = script_entry.render(trans=trans, embedded=True)
         assert '<script type="module" src="mysrc">' in response
         assert '<link rel="stylesheet" href="mycss">' in response
-        assert "<div id=\"mycontainer\" data-incoming='{}'></div>" in response
+        assert re.search(r'<div id="mycontainer" data-incoming=\'.*?\'></div>', response)
+        assert "'root': 'request.host_url/'" in response
         mock_app_dir.remove()