R1-53, S1-3: single-pass prompt render and sanitize string defaults

Author: aishaamna9b-art

tests/test_prompt.py

@@ -66,3 +66,32 @@ def test_repair_hygiene(self):
             self.assertNotIn("Traceback", repair)
             self.assertNotIn('File "', repair)
             self.assertTrue(repair.endswith("Reply:"))
+
+    def test_description_with_placeholder_not_replaced(self):
+        spec = ToolSpec("t", "Find {query} fast", (), lambda: None)
+        prompt = render_prompt("hello", [spec])
+        self.assertIn("Find {query} fast", prompt)
+        self.assertEqual(prompt.count("hello"), 1)
+
+    def test_string_default_newline_sanitized(self):
+        p = ParamSpec("x", "str", False, "a\nb")
+        spec = ToolSpec("t", "desc", (p,), lambda: None)
+        line = render_tool_line(spec)
+        self.assertNotIn("\n", line)
+        self.assertIn('x:str="a b"', line)
+
+    def test_string_default_truncated_in_prompt_only(self):
+        long_str = "a" * 30
+        p = ParamSpec("x", "str", False, long_str)
+        spec = ToolSpec("t", "desc", (p,), lambda: None)
+        line = render_tool_line(spec)
+        expected_str = ("a" * 20) + "..."
+        self.assertIn(f'x:str="{expected_str}"', line)
+        self.assertEqual(spec.params[0].default, long_str)
+
+    def test_query_with_braces_is_safe(self):
+        prompt = render_prompt("what is {tool_lines} and {query}?", [])
+        lines = prompt.splitlines()
+        self.assertTrue(lines[-2].startswith("Query: what is {tool_lines} and {query}?"))
+        self.assertEqual(lines[-1], "Reply:")
+        self.assertEqual(len([l for l in lines if l.startswith("Query:")]), 1)

tinyagent/prompt.py

@@ -1,6 +1,7 @@
 import math
 import re
 import unicodedata
+from typing import Sequence
 from .types import ToolSpec
 
 PROMPT_TEMPLATE = """Pick one tool for the query.
@@ -49,9 +50,9 @@ def render_tool_line(spec: ToolSpec) -> str:
             if p.default is None:
                 default_str = "None"
             elif isinstance(p.default, str):
-                default_val = p.default
+                default_val = _sanitize(p.default)
                 if len(default_val) > 20:
-                    default_val = default_val[:17] + "..."
+                    default_val = default_val[:20] + "..."
                 default_str = f'"{default_val}"'
             else:
                 default_str = repr(p.default)
@@ -60,7 +61,7 @@ def render_tool_line(spec: ToolSpec) -> str:
     params_str = ", ".join(rendered_params)
     return f"{spec.name}({params_str}) - {spec.description}"
 
-def render_prompt(query: str, tools: tuple[ToolSpec, ...], *, max_query_chars: int = 2000) -> str:
+def render_prompt(query: str, tools: Sequence[ToolSpec], *, max_query_chars: int = 2000) -> str:
     sanitized = _sanitize(query)[:max_query_chars]
     if not sanitized:
         raise ValueError("empty query")
@@ -70,7 +71,7 @@ def render_prompt(query: str, tools: tuple[ToolSpec, ...], *, max_query_chars: i
     else:
         tool_lines = "\n".join(render_tool_line(t) for t in tools)
 
-    return PROMPT_TEMPLATE.replace("{tool_lines}", tool_lines).replace("{query}", sanitized)
+    return PROMPT_TEMPLATE.format(tool_lines=tool_lines, query=sanitized)
 
 def render_repair_prompt(prompt: str, previous_output: str, code: str, detail: str) -> str:
     """

tinyagent/reflection.py

@@ -2,7 +2,7 @@
 import re
 import types
 import typing
-from typing import Any, Callable, Optional, Union, get_args, get_origin
+from typing import Any, Callable, Union, get_args, get_origin
 
 from .types import ParamSpec, ToolSpec
 from .registry import ToolRegistry, default_registry