Fix TemplateResponse calls to use Starlette 1.1.0+ keyword-argument style

app/tests/test_template_response_signature.py

@@ -0,0 +1,99 @@
+"""Regression test for Starlette 1.1.0+ TemplateResponse keyword-argument style.
+
+Prior to this fix, the three HTML routes called:
+    templates.TemplateResponse("name.html", {"request": request, ...})
+which passes the context dict as the second positional argument.  With the
+updated Starlette/FastAPI versions shipped in NixOS unstable (Starlette 1.1.0,
+FastAPI 0.136.3) that positional argument is the template name, causing Jinja2
+to receive a dict as a cache key and raise:
+    TypeError: unhashable type: 'dict'
+
+The fix updates every call to use keyword arguments:
+    templates.TemplateResponse(request=request, name="name.html", context={...})
+"""
+
+import ast
+import unittest
+from pathlib import Path
+
+
+SERVER_PY = Path(__file__).resolve().parents[1] / "sovran_systemsos_web" / "server.py"
+
+
+def _template_response_calls(source: str):
+    """Return a list of ast.Call nodes that are TemplateResponse calls."""
+    tree = ast.parse(source)
+    calls = []
+    for node in ast.walk(tree):
+        if not isinstance(node, ast.Call):
+            continue
+        func = node.func
+        if isinstance(func, ast.Attribute) and func.attr == "TemplateResponse":
+            calls.append(node)
+    return calls
+
+
+class TemplateResponseSignatureTests(unittest.TestCase):
+    def setUp(self):
+        self.source = SERVER_PY.read_text()
+        self.calls = _template_response_calls(self.source)
+
+    def test_at_least_one_template_response_call_found(self):
+        self.assertGreater(len(self.calls), 0, "No TemplateResponse calls found in server.py")
+
+    def test_no_old_style_positional_dict_context(self):
+        """No TemplateResponse call should pass a dict literal as its second positional arg.
+
+        The old style was:
+            templates.TemplateResponse("name.html", {"request": request, ...})
+        where args[0] is a string and args[1] is a Dict node.  That pattern
+        triggers the Starlette 1.1.0 bug.
+        """
+        for call in self.calls:
+            positional = call.args
+            if len(positional) >= 2 and isinstance(positional[1], ast.Dict):
+                self.fail(
+                    f"Found old-style TemplateResponse call at line {call.lineno}: "
+                    "second positional argument is a dict literal.  "
+                    "Use keyword arguments (request=, name=, context=) instead."
+                )
+
+    def test_request_not_duplicated_in_context(self):
+        """The 'request' key must not appear inside the context= dict when
+        request= is already passed as a dedicated keyword argument."""
+        for call in self.calls:
+            kw_dict = {kw.arg: kw.value for kw in call.keywords if isinstance(kw, ast.keyword)}
+
+            if "request" not in kw_dict:
+                continue  # no request= kwarg, nothing to check
+
+            context_node = kw_dict.get("context")
+            if not isinstance(context_node, ast.Dict):
+                continue
+
+            for key_node in context_node.keys:
+                if isinstance(key_node, ast.Constant) and key_node.value == "request":
+                    self.fail(
+                        f"TemplateResponse at line {call.lineno} passes 'request' both as "
+                        "request= keyword argument and inside the context dict."
+                    )
+
+    def test_all_calls_use_keyword_arguments(self):
+        """Every TemplateResponse call should use keyword arguments for request, name,
+        and context rather than relying on positional ordering."""
+        for call in self.calls:
+            kw_args = {kw.arg for kw in call.keywords if isinstance(kw, ast.keyword)}
+            self.assertIn(
+                "request",
+                kw_args,
+                f"TemplateResponse at line {call.lineno} is missing keyword argument 'request='.",
+            )
+            self.assertIn(
+                "name",
+                kw_args,
+                f"TemplateResponse at line {call.lineno} is missing keyword argument 'name='.",
+            )
+
+
+if __name__ == "__main__":
+    unittest.main()