Merge PR #1610: auto cast tool params to match schema

nanobot/agent/tools/base.py

@@ -52,6 +52,75 @@ class Tool(ABC):
         """
         pass
 
+    def cast_params(self, params: dict[str, Any]) -> dict[str, Any]:
+        """Apply safe schema-driven casts before validation."""
+        schema = self.parameters or {}
+        if schema.get("type", "object") != "object":
+            return params
+
+        return self._cast_object(params, schema)
+
+    def _cast_object(self, obj: Any, schema: dict[str, Any]) -> dict[str, Any]:
+        """Cast an object (dict) according to schema."""
+        if not isinstance(obj, dict):
+            return obj
+
+        props = schema.get("properties", {})
+        result = {}
+
+        for key, value in obj.items():
+            if key in props:
+                result[key] = self._cast_value(value, props[key])
+            else:
+                result[key] = value
+
+        return result
+
+    def _cast_value(self, val: Any, schema: dict[str, Any]) -> Any:
+        """Cast a single value according to schema."""
+        target_type = schema.get("type")
+
+        if target_type == "boolean" and isinstance(val, bool):
+            return val
+        if target_type == "integer" and isinstance(val, int) and not isinstance(val, bool):
+            return val
+        if target_type in self._TYPE_MAP and target_type not in ("boolean", "integer", "array", "object"):
+            expected = self._TYPE_MAP[target_type]
+            if isinstance(val, expected):
+                return val
+
+        if target_type == "integer" and isinstance(val, str):
+            try:
+                return int(val)
+            except ValueError:
+                return val
+
+        if target_type == "number" and isinstance(val, str):
+            try:
+                return float(val)
+            except ValueError:
+                return val
+
+        if target_type == "string":
+            return val if val is None else str(val)
+
+        if target_type == "boolean" and isinstance(val, str):
+            val_lower = val.lower()
+            if val_lower in ("true", "1", "yes"):
+                return True
+            if val_lower in ("false", "0", "no"):
+                return False
+            return val
+
+        if target_type == "array" and isinstance(val, list):
+            item_schema = schema.get("items")
+            return [self._cast_value(item, item_schema) for item in val] if item_schema else val
+
+        if target_type == "object" and isinstance(val, dict):
+            return self._cast_object(val, schema)
+
+        return val
+
     def validate_params(self, params: dict[str, Any]) -> list[str]:
         """Validate tool parameters against JSON schema. Returns error list (empty if valid)."""
         if not isinstance(params, dict):
@@ -63,7 +132,13 @@ class Tool(ABC):
 
     def _validate(self, val: Any, schema: dict[str, Any], path: str) -> list[str]:
         t, label = schema.get("type"), path or "parameter"
-        if t in self._TYPE_MAP and not isinstance(val, self._TYPE_MAP[t]):
+        if t == "integer" and (not isinstance(val, int) or isinstance(val, bool)):
+            return [f"{label} should be integer"]
+        if t == "number" and (
+            not isinstance(val, self._TYPE_MAP[t]) or isinstance(val, bool)
+        ):
+            return [f"{label} should be number"]
+        if t in self._TYPE_MAP and t not in ("integer", "number") and not isinstance(val, self._TYPE_MAP[t]):
             return [f"{label} should be {t}"]
 
         errors = []

nanobot/agent/tools/registry.py

@@ -44,6 +44,10 @@ class ToolRegistry:
             return f"Error: Tool '{name}' not found. Available: {', '.join(self.tool_names)}"
 
         try:
+            # Attempt to cast parameters to match schema types
+            params = tool.cast_params(params)
+            
+            # Validate parameters
             errors = tool.validate_params(params)
             if errors:
                 return f"Error: Invalid parameters for tool '{name}': " + "; ".join(errors) + _HINT

tests/test_tool_validation.py

@@ -106,3 +106,234 @@ def test_exec_extract_absolute_paths_captures_posix_absolute_paths() -> None:
     paths = ExecTool._extract_absolute_paths(cmd)
     assert "/tmp/data.txt" in paths
     assert "/tmp/out.txt" in paths
+
+
+# --- cast_params tests ---
+
+
+class CastTestTool(Tool):
+    """Minimal tool for testing cast_params."""
+
+    def __init__(self, schema: dict[str, Any]) -> None:
+        self._schema = schema
+
+    @property
+    def name(self) -> str:
+        return "cast_test"
+
+    @property
+    def description(self) -> str:
+        return "test tool for casting"
+
+    @property
+    def parameters(self) -> dict[str, Any]:
+        return self._schema
+
+    async def execute(self, **kwargs: Any) -> str:
+        return "ok"
+
+
+def test_cast_params_string_to_int() -> None:
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"count": {"type": "integer"}},
+        }
+    )
+    result = tool.cast_params({"count": "42"})
+    assert result["count"] == 42
+    assert isinstance(result["count"], int)
+
+
+def test_cast_params_string_to_number() -> None:
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"rate": {"type": "number"}},
+        }
+    )
+    result = tool.cast_params({"rate": "3.14"})
+    assert result["rate"] == 3.14
+    assert isinstance(result["rate"], float)
+
+
+def test_cast_params_string_to_bool() -> None:
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"enabled": {"type": "boolean"}},
+        }
+    )
+    assert tool.cast_params({"enabled": "true"})["enabled"] is True
+    assert tool.cast_params({"enabled": "false"})["enabled"] is False
+    assert tool.cast_params({"enabled": "1"})["enabled"] is True
+
+
+def test_cast_params_array_items() -> None:
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {
+                "nums": {"type": "array", "items": {"type": "integer"}},
+            },
+        }
+    )
+    result = tool.cast_params({"nums": ["1", "2", "3"]})
+    assert result["nums"] == [1, 2, 3]
+
+
+def test_cast_params_nested_object() -> None:
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {
+                "config": {
+                    "type": "object",
+                    "properties": {
+                        "port": {"type": "integer"},
+                        "debug": {"type": "boolean"},
+                    },
+                },
+            },
+        }
+    )
+    result = tool.cast_params({"config": {"port": "8080", "debug": "true"}})
+    assert result["config"]["port"] == 8080
+    assert result["config"]["debug"] is True
+
+
+def test_cast_params_bool_not_cast_to_int() -> None:
+    """Booleans should not be silently cast to integers."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"count": {"type": "integer"}},
+        }
+    )
+    result = tool.cast_params({"count": True})
+    assert result["count"] is True
+    errors = tool.validate_params(result)
+    assert any("count should be integer" in e for e in errors)
+
+
+def test_cast_params_preserves_empty_string() -> None:
+    """Empty strings should be preserved for string type."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"name": {"type": "string"}},
+        }
+    )
+    result = tool.cast_params({"name": ""})
+    assert result["name"] == ""
+
+
+def test_cast_params_bool_string_false() -> None:
+    """Test that 'false', '0', 'no' strings convert to False."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"flag": {"type": "boolean"}},
+        }
+    )
+    assert tool.cast_params({"flag": "false"})["flag"] is False
+    assert tool.cast_params({"flag": "False"})["flag"] is False
+    assert tool.cast_params({"flag": "0"})["flag"] is False
+    assert tool.cast_params({"flag": "no"})["flag"] is False
+    assert tool.cast_params({"flag": "NO"})["flag"] is False
+
+
+def test_cast_params_bool_string_invalid() -> None:
+    """Invalid boolean strings should not be cast."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"flag": {"type": "boolean"}},
+        }
+    )
+    # Invalid strings should be preserved (validation will catch them)
+    result = tool.cast_params({"flag": "random"})
+    assert result["flag"] == "random"
+    result = tool.cast_params({"flag": "maybe"})
+    assert result["flag"] == "maybe"
+
+
+def test_cast_params_invalid_string_to_int() -> None:
+    """Invalid strings should not be cast to integer."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"count": {"type": "integer"}},
+        }
+    )
+    result = tool.cast_params({"count": "abc"})
+    assert result["count"] == "abc"  # Original value preserved
+    result = tool.cast_params({"count": "12.5.7"})
+    assert result["count"] == "12.5.7"
+
+
+def test_cast_params_invalid_string_to_number() -> None:
+    """Invalid strings should not be cast to number."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"rate": {"type": "number"}},
+        }
+    )
+    result = tool.cast_params({"rate": "not_a_number"})
+    assert result["rate"] == "not_a_number"
+
+
+def test_validate_params_bool_not_accepted_as_number() -> None:
+    """Booleans should not pass number validation."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"rate": {"type": "number"}},
+        }
+    )
+    errors = tool.validate_params({"rate": False})
+    assert any("rate should be number" in e for e in errors)
+
+
+def test_cast_params_none_values() -> None:
+    """Test None handling for different types."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {
+                "name": {"type": "string"},
+                "count": {"type": "integer"},
+                "items": {"type": "array"},
+                "config": {"type": "object"},
+            },
+        }
+    )
+    result = tool.cast_params(
+        {
+            "name": None,
+            "count": None,
+            "items": None,
+            "config": None,
+        }
+    )
+    # None should be preserved for all types
+    assert result["name"] is None
+    assert result["count"] is None
+    assert result["items"] is None
+    assert result["config"] is None
+
+
+def test_cast_params_single_value_not_auto_wrapped_to_array() -> None:
+    """Single values should NOT be automatically wrapped into arrays."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"items": {"type": "array"}},
+        }
+    )
+    # Non-array values should be preserved (validation will catch them)
+    result = tool.cast_params({"items": 5})
+    assert result["items"] == 5  # Not wrapped to [5]
+    result = tool.cast_params({"items": "text"})
+    assert result["items"] == "text"  # Not wrapped to ["text"]