is.js

var FUNCTION = 'function',
    OBJECT = 'object',
    FASTNBINDING = '_fastn_binding',
    FASTNPROPERTY = '_fastn_property',
    FASTNCOMPONENT = '_fastn_component',
    DEFAULTBINDING = '_default_binding';

function isComponent(thing){
    return thing && typeof thing === OBJECT && FASTNCOMPONENT in thing;
}

function isBindingObject(thing){
    return thing && typeof thing === OBJECT && FASTNBINDING in thing;
}

function isBinding(thing){
    return typeof thing === FUNCTION && FASTNBINDING in thing;
}

function isProperty(thing){
    return typeof thing === FUNCTION && FASTNPROPERTY in thing;
}

function isDefaultBinding(thing){
    return typeof thing === FUNCTION && FASTNBINDING in thing && DEFAULTBINDING in thing;
}

module.exports = {
    component: isComponent,
    bindingObject: isBindingObject,
    binding: isBinding,
    defaultBinding: isDefaultBinding,
    property: isProperty
};