Avalonia/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_GetValue.cs

// Copyright (c) The Avalonia Project. All rights reserved.
// Licensed under the MIT license. See licence.md file in the project root for full license information.

using System;
using Xunit;

namespace Avalonia.Base.UnitTests
{
    public class AvaloniaObjectTests_GetValue
    {
        [Fact]
        public void GetValue_Returns_Default_Value()
        {
            Class1 target = new Class1();

            Assert.Equal("foodefault", target.GetValue(Class1.FooProperty));
        }

        [Fact]
        public void GetValue_Returns_Overridden_Default_Value()
        {
            Class2 target = new Class2();

            Assert.Equal("foooverride", target.GetValue(Class1.FooProperty));
        }

        [Fact]
        public void GetValue_Returns_Set_Value()
        {
            Class1 target = new Class1();

            target.SetValue(Class1.FooProperty, "newvalue");

            Assert.Equal("newvalue", target.GetValue(Class1.FooProperty));
        }

        [Fact]
        public void GetValue_Returns_Inherited_Value()
        {
            Class1 parent = new Class1();
            Class2 child = new Class2 { Parent = parent };

            parent.SetValue(Class1.BazProperty, "changed");

            Assert.Equal("changed", child.GetValue(Class1.BazProperty));
        }

        [Fact]
        public void GetValue_Throws_Exception_For_Unregistered_Property()
        {
            var target = new Class3();

            Assert.Throws<ArgumentException>(() => target.GetValue(Class1.FooProperty));
        }

        private class Class1 : AvaloniaObject
        {
            public static readonly StyledProperty<string> FooProperty =
                AvaloniaProperty.Register<Class1, string>("Foo", "foodefault");

            public static readonly StyledProperty<string> BazProperty =
                AvaloniaProperty.Register<Class1, string>("Baz", "bazdefault", true);
        }

        private class Class2 : Class1
        {
            static Class2()
            {
                FooProperty.OverrideDefaultValue(typeof(Class2), "foooverride");
            }

            public Class1 Parent
            {
                get { return (Class1)InheritanceParent; }
                set { InheritanceParent = value; }
            }
        }

        private class Class3 : AvaloniaObject
        {
        }
    }
}