@tool
extends RefCounted
class_name MCPValidator
## Parameter validation utilities for MCP commands.
## Provides Zod-like validation for GDScript (ISO 5055 compliance).
## Validation result
class ValidationResult:
var valid: bool
var error_code: String
var error_message: String
func _init(p_valid: bool = true, p_code: String = "", p_message: String = "") -> void:
valid = p_valid
error_code = p_code
error_message = p_message
static func ok() -> ValidationResult:
return ValidationResult.new(true)
static func fail(code: String, message: String) -> ValidationResult:
return ValidationResult.new(false, code, message)
## Validate that a required parameter exists and is not null/empty
static func require_string(params: Dictionary, key: String, min_length: int = 1, max_length: int = 1000) -> ValidationResult:
if not params.has(key):
return ValidationResult.fail("MISSING_PARAM", "Required parameter missing: %s" % key)
var value = params[key]
if value == null:
return ValidationResult.fail("NULL_PARAM", "Parameter cannot be null: %s" % key)
if not value is String:
return ValidationResult.fail("INVALID_TYPE", "Parameter must be a string: %s (got %s)" % [key, typeof(value)])
var str_value: String = value
if str_value.length() < min_length:
return ValidationResult.fail("TOO_SHORT", "Parameter %s must be at least %d characters" % [key, min_length])
if str_value.length() > max_length:
return ValidationResult.fail("TOO_LONG", "Parameter %s must be at most %d characters" % [key, max_length])
return ValidationResult.ok()
## Validate a resource path (res://)
static func require_resource_path(params: Dictionary, key: String) -> ValidationResult:
var result := require_string(params, key)
if not result.valid:
return result
var path: String = params[key]
# Allow paths without res:// prefix (will be normalized)
if not path.begins_with("res://") and not path.begins_with("/"):
# Relative path, will be prefixed with res://
return ValidationResult.ok()
if path.begins_with("res://"):
if path.length() < 7: # "res://" is 6 chars, need at least 1 more
return ValidationResult.fail("INVALID_PATH", "Resource path is too short: %s" % path)
return ValidationResult.ok()
return ValidationResult.fail("INVALID_PATH", "Path must start with res:// or be relative: %s" % path)
## Validate a scene path (.tscn or .scn)
static func require_scene_path(params: Dictionary, key: String) -> ValidationResult:
var result := require_resource_path(params, key)
if not result.valid:
return result
var path: String = params[key]
var ext := path.get_extension().to_lower()
if ext != "tscn" and ext != "scn":
return ValidationResult.fail("INVALID_EXTENSION", "Scene path must have .tscn or .scn extension: %s" % path)
return ValidationResult.ok()
## Validate a script path (.gd)
static func require_script_path(params: Dictionary, key: String) -> ValidationResult:
var result := require_resource_path(params, key)
if not result.valid:
return result
var path: String = params[key]
var ext := path.get_extension().to_lower()
if ext != "gd" and ext != "gdscript":
return ValidationResult.fail("INVALID_EXTENSION", "Script path must have .gd extension: %s" % path)
return ValidationResult.ok()
## Validate a node type name
static func require_node_type(params: Dictionary, key: String) -> ValidationResult:
var result := require_string(params, key, 1, 100)
if not result.valid:
return result
var type_name: String = params[key]
if not MCPNodeFactory.is_valid_node_type(type_name):
return ValidationResult.fail("INVALID_NODE_TYPE", "Unknown or non-instantiable node type: %s" % type_name)
return ValidationResult.ok()
## Validate a node name (valid identifier)
static func require_node_name(params: Dictionary, key: String) -> ValidationResult:
var result := require_string(params, key, 1, 100)
if not result.valid:
return result
var name: String = params[key]
# Check for invalid characters
var invalid_chars := [":", "/", "\\", ".", "@", "\"", "'"]
for char in invalid_chars:
if name.contains(char):
return ValidationResult.fail("INVALID_NAME", "Node name contains invalid character '%s': %s" % [char, name])
return ValidationResult.ok()
## Validate an integer parameter
static func require_int(params: Dictionary, key: String, min_val: int = -2147483648, max_val: int = 2147483647) -> ValidationResult:
if not params.has(key):
return ValidationResult.fail("MISSING_PARAM", "Required parameter missing: %s" % key)
var value = params[key]
if value == null:
return ValidationResult.fail("NULL_PARAM", "Parameter cannot be null: %s" % key)
if not (value is int or value is float):
return ValidationResult.fail("INVALID_TYPE", "Parameter must be an integer: %s" % key)
var int_value: int = int(value)
if int_value < min_val:
return ValidationResult.fail("OUT_OF_RANGE", "Parameter %s must be >= %d" % [key, min_val])
if int_value > max_val:
return ValidationResult.fail("OUT_OF_RANGE", "Parameter %s must be <= %d" % [key, max_val])
return ValidationResult.ok()
## Validate a float parameter
static func require_float(params: Dictionary, key: String, min_val: float = -INF, max_val: float = INF) -> ValidationResult:
if not params.has(key):
return ValidationResult.fail("MISSING_PARAM", "Required parameter missing: %s" % key)
var value = params[key]
if value == null:
return ValidationResult.fail("NULL_PARAM", "Parameter cannot be null: %s" % key)
if not (value is int or value is float):
return ValidationResult.fail("INVALID_TYPE", "Parameter must be a number: %s" % key)
var float_value: float = float(value)
if float_value < min_val:
return ValidationResult.fail("OUT_OF_RANGE", "Parameter %s must be >= %f" % [key, min_val])
if float_value > max_val:
return ValidationResult.fail("OUT_OF_RANGE", "Parameter %s must be <= %f" % [key, max_val])
return ValidationResult.ok()
## Validate a boolean parameter
static func require_bool(params: Dictionary, key: String) -> ValidationResult:
if not params.has(key):
return ValidationResult.fail("MISSING_PARAM", "Required parameter missing: %s" % key)
var value = params[key]
if value == null:
return ValidationResult.fail("NULL_PARAM", "Parameter cannot be null: %s" % key)
if not value is bool:
return ValidationResult.fail("INVALID_TYPE", "Parameter must be a boolean: %s" % key)
return ValidationResult.ok()
## Validate a dictionary parameter
static func require_dict(params: Dictionary, key: String) -> ValidationResult:
if not params.has(key):
return ValidationResult.fail("MISSING_PARAM", "Required parameter missing: %s" % key)
var value = params[key]
if value == null:
return ValidationResult.fail("NULL_PARAM", "Parameter cannot be null: %s" % key)
if not value is Dictionary:
return ValidationResult.fail("INVALID_TYPE", "Parameter must be a dictionary: %s" % key)
return ValidationResult.ok()
## Validate an array parameter
static func require_array(params: Dictionary, key: String, min_length: int = 0, max_length: int = 1000) -> ValidationResult:
if not params.has(key):
return ValidationResult.fail("MISSING_PARAM", "Required parameter missing: %s" % key)
var value = params[key]
if value == null:
return ValidationResult.fail("NULL_PARAM", "Parameter cannot be null: %s" % key)
if not value is Array:
return ValidationResult.fail("INVALID_TYPE", "Parameter must be an array: %s" % key)
var arr: Array = value
if arr.size() < min_length:
return ValidationResult.fail("TOO_SHORT", "Array %s must have at least %d elements" % [key, min_length])
if arr.size() > max_length:
return ValidationResult.fail("TOO_LONG", "Array %s must have at most %d elements" % [key, max_length])
return ValidationResult.ok()
## Validate an optional string parameter (returns ok if missing)
static func optional_string(params: Dictionary, key: String, min_length: int = 0, max_length: int = 1000) -> ValidationResult:
if not params.has(key) or params[key] == null:
return ValidationResult.ok()
return require_string(params, key, min_length, max_length)
## Validate an optional int parameter
static func optional_int(params: Dictionary, key: String, min_val: int = -2147483648, max_val: int = 2147483647) -> ValidationResult:
if not params.has(key) or params[key] == null:
return ValidationResult.ok()
return require_int(params, key, min_val, max_val)
## Validate an optional bool parameter
static func optional_bool(params: Dictionary, key: String) -> ValidationResult:
if not params.has(key) or params[key] == null:
return ValidationResult.ok()
return require_bool(params, key)
## Validate an optional dict parameter
static func optional_dict(params: Dictionary, key: String) -> ValidationResult:
if not params.has(key) or params[key] == null:
return ValidationResult.ok()
return require_dict(params, key)
## Combine multiple validation results
static func all(results: Array[ValidationResult]) -> ValidationResult:
for result in results:
if not result.valid:
return result
return ValidationResult.ok()
