go-types/test/isUndefinedTest.js

Type-checking utilities for JavaScript

"use strict";

var assert = require("chai").assert;
var isUndefined = require("../src/isUndefined");

suite("#isUndefined", function () {

    test("undefined", function () {
        assert.equal(isUndefined(), true);
        assert.equal(isUndefined(undefined), true);
        assert.equal(isUndefined(void 0), true);
    });

    test("not undefined", function () {
        assert.equal(isUndefined(null), false);
        assert.equal(isUndefined(false), false);
        assert.equal(isUndefined(0), false);
        assert.equal(isUndefined(""), false);
        assert.equal(isUndefined(NaN), false);
        assert.equal(isUndefined({}), false);
        assert.equal(isUndefined([]), false);
        assert.equal(isUndefined(function () {}), false);
    });
});