protobuf/csharp/src/Google.Protobuf.Test/EqualityTester.cs

#region Copyright notice and license
// Protocol Buffers - Google's data interchange format
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// https://developers.google.com/protocol-buffers/
//
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//
//     * Redistributions of source code must retain the above copyright
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// in the documentation and/or other materials provided with the
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// contributors may be used to endorse or promote products derived from
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#endregion

using System;
using NUnit.Framework;

namespace Google.Protobuf
{
    /// <summary>
    /// Helper methods when testing equality. NUnit's Assert.AreEqual and
    /// Assert.AreNotEqual methods try to be clever with collections, which can
    /// be annoying...
    /// </summary>
    internal static class EqualityTester
    {
        public static void AssertEquality<T>(T first, T second) where T : IEquatable<T>
        {
            Assert.IsTrue(first.Equals(second));
            Assert.IsTrue(first.Equals((object) second));
            Assert.AreEqual(first.GetHashCode(), second.GetHashCode());
        }

        public static void AssertInequality<T>(T first, T second) where T : IEquatable<T>
        {
            Assert.IsFalse(first.Equals(second));
            Assert.IsFalse(first.Equals((object) second));
            // While this isn't a requirement, the chances of this test failing due to
            // coincidence rather than a bug are very small.
            if (first != null && second != null)
            {
                Assert.AreNotEqual(first.GetHashCode(), second.GetHashCode());
            }
        }
    }
}