add test_nested_bad_properties (Tool 21 bug reproduction)

test_devstral.py

@@ -402,7 +402,63 @@ def test_openclaw_tool_schema():
         record("openclaw tool schema", True, "Middleware fixed parameters.properties=[] → {}")
 
 
-# ── 8. OpenClaw full payload (chat_template_kwargs + tools) ─
+# ── 8. Nested properties=[] in tool schema (Tool 21 bug) ────
+
+def test_nested_bad_properties():
+    """
+    Reproduce the exact Tool 21 400 error:
+    schema['properties']['fields']['items']['properties'] = []
+    
+    This happens when a tool has an array-of-objects parameter where
+    the items' properties field is [] instead of {}. The middleware
+    must recurse into the schema to fix ALL properties fields.
+    """
+    print(f"\n{'='*60}")
+    print(f"[{ts()}] TEST: Nested properties=[] in tool schema (Tool 21 bug)")
+    print(f"{'='*60}")
+
+    # This is the exact shape that causes: "Tool 21 function has invalid 'parameters' schema:
+    # [] is not of type 'object' ... On schema['properties']['fields']['items']['properties']"
+    tools = [{
+        "type": "function",
+        "function": {
+            "name": "message",
+            "description": "Send a message",
+            "parameters": {
+                "type": "object",
+                "properties": {
+                    "fields": {
+                        "type": "array",
+                        "items": {
+                            "type": "object",
+                            "properties": []  # <-- THIS causes the 400
+                        }
+                    }
+                }
+            }
+        }
+    }]
+
+    with make_client() as c:
+        r = c.post(f"{API_BASE}/chat/completions", json={
+            "model": MODEL,
+            "messages": [{"role": "user", "content": "Send a message to Bob"}],
+            "tools": tools,
+            "tool_choice": "auto",
+            "stream": False,
+            "max_tokens": 128,
+        })
+        print(f"[{ts()}] Status: {r.status_code}")
+        body = r.json()
+        if r.status_code != 200:
+            print(f"[{ts()}] Error: {json.dumps(body, indent=2)[:500]}")
+            record("nested bad properties", False, f"HTTP {r.status_code}: {json.dumps(body)[:200]}")
+            return
+        print(f"[{ts()}] Success — middleware fixed nested properties=[] to {{}}")
+        record("nested bad properties", True, "Middleware fixed nested properties.properties=[] to {}")
+
+
+# ── 9. OpenClaw full payload (chat_template_kwargs + tools) ─
 
 def test_openclaw_full_payload():
     """
@@ -472,6 +528,7 @@ def main():
     test_tool_response_flow()
     test_param_sweep()
     test_openclaw_tool_schema()
+    test_nested_bad_properties()
     test_openclaw_full_payload()
 
     print(f"\n\n{'='*60}")