Function boa::builtins::array::find_index

pub fn find_index(
    this: &Value, 
    args: &[Value], 
    interpreter: &mut Interpreter
) -> ResultValue

Array.prototype.findIndex ( predicate [ , thisArg ] )

This method executes the provided predicate function for each element of the array. If the predicate function returns true for an element, this method returns the index of the element. If all elements return false, the value -1 is returned. https://tc39.es/ecma262/#sec-array.prototype.findindex/