Function includes

test/unit/static/js/proclaim.js:350–378

(haystack, needle)

    // Utility for checking whether an object contains another object
    function includes (haystack, needle) {
        /* jshint maxdepth: 3*/
        var i;

        // Array#indexOf, but ie...
        if (isArray(haystack)) {
            for (i = haystack.length - 1; i >= 0; i = i - 1) {
                if (haystack[i] === needle) {
                    return true;
                }
            }
        }

        // String#indexOf
        if (typeof haystack === 'string') {
            if (haystack.indexOf(needle) !== -1) {
                return true;
            }
        }

        // Object#hasOwnProperty
        if (isPlainObject(haystack)) {
            if (haystack.hasOwnProperty(needle)) {
                return true;
            }
        }

        return false;
    }

    // Utility for checking whether a value is an array
    var isArray = Array.isArray || function (val) {