assertType

assertType<T>(value, validator, errorMessage): asserts value is T

Assert that a value is of type T, throwing if validation fails

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Default value	Description
value	unknown	undefined	The value to assert
validator	(v) => v is T	undefined	A type guard function to validate the value
errorMessage	string	'Type assertion failed'	Optional custom error message

Returns

asserts value is T

Throws

Error if validation fails

Example

const response = await client.functions.invoke('get-user')
assertType(response.data, isObject, 'Expected user object')
// Now response.data is typed as Record<string, unknown>