describe('PIXI.utils', function ()
{
    describe('uid', function ()
    {
        it('should exist', function ()
        {
            expect(PIXI.utils.uid)
                .to.be.a('function');
        });

        it('should return a number', function ()
        {
            expect(PIXI.utils.uid())
                .to.be.a('number');
        });
    });

    describe('hex2rgb', function ()
    {
        it('should exist', function ()
        {
            expect(PIXI.utils.hex2rgb)
                .to.be.a('function');
        });

        // it('should properly convert number to rgb array');
    });

    describe('hex2string', function ()
    {
        it('should exist', function ()
        {
            expect(PIXI.utils.hex2string)
                .to.be.a('function');
        });

        // it('should properly convert number to hex color string');
    });

    describe('rgb2hex', function ()
    {
        it('should exist', function ()
        {
            expect(PIXI.utils.rgb2hex)
                .to.be.a('function');
        });

        // it('should properly convert rgb array to hex color string');
    });

    describe('getResolutionOfUrl', function ()
    {
        it('should exist', function ()
        {
            expect(PIXI.utils.getResolutionOfUrl)
                .to.be.a('function');
        });

        // it('should return the correct resolution based on a URL');
    });

    describe('sayHello', function ()
    {
        it('should exist', function ()
        {
            expect(PIXI.utils.sayHello)
                .to.be.a('function');
        });
    });

    describe('isWebGLSupported', function ()
    {
        it('should exist', function ()
        {
            expect(PIXI.utils.isWebGLSupported)
                .to.be.a('function');
        });
    });

    describe('sign', function ()
    {
        it('should return 0 for 0', function ()
        {
            expect(PIXI.utils.sign(0))
                .to.be.equal(0);
        });

        it('should return -1 for negative numbers', function ()
        {
            for (var i = 0; i < 10; i += 1)
            {
                expect(PIXI.utils.sign(-Math.random()))
                    .to.be.equal(-1);
            }
        });

        it('should return 1 for positive numbers', function ()
        {
            for (var i = 0; i < 10; i += 1)
            {
                expect(PIXI.utils.sign(Math.random() + 0.000001))
                    .to.be.equal(1);
            }
        });
    });

    describe('.removeItems', function ()
    {
        var arr;

        beforeEach(function ()
        {
            arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
        });

        it('should return if the start index is greater than or equal to the length of the array', function ()
        {
            PIXI.utils.removeItems(arr, arr.length + 1, 5);
            expect(arr.length).to.be.equal(10);
        });

        it('should return if the remove count is 0', function ()
        {
            PIXI.utils.removeItems(arr, 2, 0);
            expect(arr.length).to.be.equal(10);
        });

        it('should remove the number of elements specified from the array, starting from the start index', function ()
        {
            var res = [1, 2, 3, 8, 9, 10];
            PIXI.utils.removeItems(arr, 3, 4);
            expect(arr).to.be.deep.equal(res);
        });

        it('should remove rest of elements if the delete count is > than the number of elements after start index', function ()
        {
            var res = [1, 2, 3, 4, 5, 6, 7];
            PIXI.utils.removeItems(arr, 7, 10);
            expect(arr).to.be.deep.equal(res);
        });
    });
});