defineSuite([
        'Core/QuadraticRealPolynomial',
        'Core/Math'
    ], function(
        QuadraticRealPolynomial,
        CesiumMath) {
    'use strict';

    it('discriminant throws without a', function() {
        expect(function() {
            QuadraticRealPolynomial.computeDiscriminant();
        }).toThrowDeveloperError();
    });

    it('discriminant throws without b', function() {
        expect(function() {
            QuadraticRealPolynomial.computeDiscriminant(1.0);
        }).toThrowDeveloperError();
    });

    it('discriminant throws without c', function() {
        expect(function() {
            QuadraticRealPolynomial.computeDiscriminant(1.0, 1.0);
        }).toThrowDeveloperError();
    });

    it('discriminant', function() {
        var discriminant = QuadraticRealPolynomial.computeDiscriminant(1.0, 2.0, 3.0);
        expect(discriminant).toEqual(-8.0);
    });

    it('real roots throws without a', function() {
        expect(function() {
            QuadraticRealPolynomial.computeRealRoots();
        }).toThrowDeveloperError();
    });

    it('real roots throws without b', function() {
        expect(function() {
            QuadraticRealPolynomial.computeRealRoots(1.0);
        }).toThrowDeveloperError();
    });

    it('real roots throws without c', function() {
        expect(function() {
            QuadraticRealPolynomial.computeRealRoots(1.0, 1.0);
        }).toThrowDeveloperError();
    });

    it('negative b', function() {
        var roots = QuadraticRealPolynomial.computeRealRoots(2.0, -4.0, -6.0);
        expect(roots.length).toEqual(2);
        expect(roots[0]).toEqual(-1.0);
        expect(roots[1]).toEqual(3.0);
    });

    it('positive b', function() {
        var roots = QuadraticRealPolynomial.computeRealRoots(2.0, 4.0, -6.0);
        expect(roots.length).toEqual(2);
        expect(roots[0]).toEqual(-3.0);
        expect(roots[1]).toEqual(1.0);
    });

    it('marginally negative radical case', function() {
        var roots = QuadraticRealPolynomial.computeRealRoots(2.0, -3.999999999999999, 2);
        expect(roots.length).toEqual(2);
        expect(roots[0]).toEqualEpsilon(1.0, CesiumMath.EPSILON15);
        expect(roots[1]).toEqualEpsilon(1.0, CesiumMath.EPSILON15);
    });

    it('complex roots', function() {
        var roots = QuadraticRealPolynomial.computeRealRoots(2.0, -4.0, 6.0);
        expect(roots.length).toEqual(0);
    });

    it('intractable case', function() {
        var roots = QuadraticRealPolynomial.computeRealRoots(0.0, 0.0, -3.0);
        expect(roots.length).toEqual(0);
    });

    it('linear case', function() {
        var roots = QuadraticRealPolynomial.computeRealRoots(0.0, 2.0, 8.0);
        expect(roots.length).toEqual(1);
        expect(roots[0]).toEqual(-4.0);
    });

    it('2nd order monomial case', function() {
        var roots = QuadraticRealPolynomial.computeRealRoots(3.0, 0.0, 0.0);
        expect(roots.length).toEqual(2);
        expect(roots[0]).toEqual(0.0);
        expect(roots[1]).toEqual(0.0);
    });

    it('parabolic case with complex roots', function() {
        var roots = QuadraticRealPolynomial.computeRealRoots(3.0, 0.0, 18.0);
        expect(roots.length).toEqual(0);
    });

    it('parabolic case with real roots', function() {
        var roots = QuadraticRealPolynomial.computeRealRoots(2.0, 0.0, -18.0);
        expect(roots.length).toEqual(2);
        expect(roots[0]).toEqual(-3.0);
        expect(roots[1]).toEqual(3.0);
    });

    it('zero and negative root case', function() {
        var roots = QuadraticRealPolynomial.computeRealRoots(2.0, 6.0, 0.0);
        expect(roots.length).toEqual(2);
        expect(roots[0]).toEqual(-3.0);
        expect(roots[1]).toEqual(0.0);
    });

    it('zero and positive root case', function() {
        var roots = QuadraticRealPolynomial.computeRealRoots(2.0, -6.0, 0.0);
        expect(roots.length).toEqual(2);
        expect(roots[0]).toEqual(0.0);
        expect(roots[1]).toEqual(3.0);
    });
});