SystemExtensions/SystemExtensions.Tests/Structures/Int32BitStructTests.cs

using Microsoft.VisualStudio.TestTools.UnitTesting;

namespace System.Structures.BitStructures.Tests;

[TestClass]
public class Int32BitStructTests
{
    [DataTestMethod]
    [DataRow(-1)]
    [DataRow(int.MaxValue)]
    public void TestSetValueInt(int value)
    {
        Int32BitStruct int32 = value;
        Assert.IsTrue(int32 == value);
    }

    [DataTestMethod]
    [DataRow(1)]
    public void TestSetValueUint(int value)
    {
        Int32BitStruct int32 = value;
        Assert.IsTrue(int32 == value);
    }

    public void TestSetMaxValueUint()
    {
        Int32BitStruct int32 = uint.MaxValue;
        Assert.IsTrue(int32 == uint.MaxValue);
    }

    [DataTestMethod]
    [DataRow(0)]
    [DataRow(int.MaxValue)]
    [DataRow(int.MinValue)]
    public void TestGetBit(int value)
    {
        Int32BitStruct int32 = value;
        Assert.IsTrue(value >= 0 ? int32.Bit31 == 0 : int32.Bit31 == 1);
    }

    [DataTestMethod]
    [DataRow(0)]
    [DataRow(1)]
    public void TestSetBit(int value)
    {
        Int32BitStruct int32 = 0;
        int32.Bit0 = (uint)value;
        Assert.IsTrue(int32 == value);
    }

    [TestMethod]
    public void TestUseCaseExample()
    {
        // Set value = -1, represented as MSB being 1 and the rest 0.
        Int32BitStruct int32 = int.MinValue;

        // Test that MSB is 1.
        Assert.IsTrue(int32.Bit31 == 1);

        // Set MSB to 0 and test that everything else is 0.
        int32.Bit31 = 0;
        Assert.IsTrue(int32 == 0);

        // Set the least 31 significant bits (all besides MSB) to 1.
        int32 = int.MaxValue;

        // Set the MSB to 1 and test that everything is 1.
        int32.Bit31 = 1;
        Assert.IsTrue(int32 == uint.MaxValue);
    }
}