refactor: fix slot context behavior (#445)

tests/testutils.py

@@ -1,6 +1,7 @@
+from typing import List
 from unittest.mock import Mock
 
-from django.template import Context
+from django.template import Context, Node
 from django.template.response import TemplateResponse
 from django.test import SimpleTestCase
 
@@ -32,3 +33,22 @@ def create_and_process_template_response(template, context=None, use_middleware=
     else:
         response.render()
     return response.content.decode("utf-8")
+
+
+def print_nodes(nodes: List[Node], indent=0) -> None:
+    """
+    Render a Nodelist, inlining child nodes with extra on separate lines and with
+    extra indentation.
+    """
+    for node in nodes:
+        child_nodes: List[Node] = []
+        for attr in node.child_nodelists:
+            attr_child_nodes = getattr(node, attr, None) or []
+            if attr_child_nodes:
+                child_nodes.extend(attr_child_nodes)
+
+        repr = str(node)
+        repr = "\n".join([(" " * 4 * indent) + line for line in repr.split("\n")])
+        print(repr)
+        if child_nodes:
+            print_nodes(child_nodes, indent=indent + 1)