fix edge case casting and more test cases

nanobot/agent/tools/base.py

@@ -57,7 +57,8 @@ class Tool(ABC):
     def cast_params(self, params: dict[str, Any]) -> dict[str, Any]:
         """
         Attempt to cast parameters to match schema types.
-        Returns modified params dict. Raises ValueError if casting is impossible.
+        Returns modified params dict. If casting fails, returns original value
+        and logs a debug message, allowing validation to catch the error.
         """
         schema = self.parameters or {}
         if schema.get("type", "object") != "object":
@@ -107,7 +108,7 @@ class Tool(ABC):
             if target_type == "integer":
                 if isinstance(val, bool):
                     # Don't silently convert bool to int
-                    raise ValueError(f"Cannot cast bool to integer")
+                    raise ValueError("Cannot cast bool to integer")
                 if isinstance(val, str):
                     return int(val)
                 if isinstance(val, (int, float)):
@@ -116,7 +117,7 @@ class Tool(ABC):
             elif target_type == "number":
                 if isinstance(val, bool):
                     # Don't silently convert bool to number
-                    raise ValueError(f"Cannot cast bool to number")
+                    raise ValueError("Cannot cast bool to number")
                 if isinstance(val, str):
                     return float(val)
                 if isinstance(val, (int, float)):
@@ -130,7 +131,13 @@ class Tool(ABC):
 
             elif target_type == "boolean":
                 if isinstance(val, str):
-                    return val.lower() in ("true", "1", "yes")
+                    val_lower = val.lower()
+                    if val_lower in ("true", "1", "yes"):
+                        return True
+                    elif val_lower in ("false", "0", "no"):
+                        return False
+                    # For other strings, raise error to let validation handle it
+                    raise ValueError(f"Cannot convert string '{val}' to boolean")
                 return bool(val)
 
             elif target_type == "array":
@@ -142,10 +149,11 @@ class Tool(ABC):
                 # Preserve None vs empty array distinction
                 if val is None:
                     return val
-                # Try to convert single value to array
+                # Empty string → empty array
                 if val == "":
                     return []
-                return [val]
+                # Don't auto-wrap single values, let validation catch the error
+                raise ValueError(f"Cannot convert {type(val).__name__} to array")
 
             elif target_type == "object":
                 if isinstance(val, dict):

tests/test_tool_validation.py

@@ -225,3 +225,139 @@ def test_cast_params_preserves_empty_string() -> None:
     )
     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_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"]
+
+
+def test_cast_params_empty_string_to_array() -> None:
+    """Empty string should convert to empty array."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"items": {"type": "array"}},
+        }
+    )
+    result = tool.cast_params({"items": ""})
+    assert result["items"] == []
+
+
+def test_cast_params_empty_string_to_object() -> None:
+    """Empty string should convert to empty object."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"config": {"type": "object"}},
+        }
+    )
+    result = tool.cast_params({"config": ""})
+    assert result["config"] == {}
+
+
+def test_cast_params_float_to_int() -> None:
+    """Float values should be cast to integers."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"count": {"type": "integer"}},
+        }
+    )
+    result = tool.cast_params({"count": 42.7})
+    assert result["count"] == 42
+    assert isinstance(result["count"], int)