predicates/src/instanceOf.js

'use strict';

var handleCurry = require('./utils/handleCurry'),
    isFunction = require('./function');

/**
 * Checks whether a value is an instance of given "class"
 *
 * **Aliases** _instance_
 *
 * @function instanceOf
 *
 * @example
 * var is = require('predicates');
 *
 * var Duck = function() {};
 * var Car = function() {};
 *
 * var isDuck = is.instanceOf(Duck);
 *
 * isDuck(new Duck); // true
 * // same as
 * is.instanceOf(Duck, new Duck); // true
 *
 * isDuck(new Car); // false
 *
 *
 * @param {Function} clazz
 * @param {*} [value]
 * @throws {TypeError} if class is not a function
 * @returns {(Boolean|Predicate)} bool if at least two arguments provided, otherwise a predicate
 */
module.exports = function isInstanceOf(clazz) {
    if (!isFunction(clazz)) {
        throw new TypeError('Class must be a function');
    }
    return handleCurry.call(this, arguments, function isInstanceOfPredicate(value) {
        return value instanceof clazz;
    });
};