RofloCalc/RofloCalc.Test/MainWindowTests.cs

using Avalonia;
using Avalonia.Controls;
using Avalonia.Headless;
using NUnit.Framework;
using NUnit.Framework.Legacy;

namespace RofloCalc.Test;

[TestFixture]
public class CalculatorTests
{
    private MainWindow _mainWindow;

    [OneTimeSetUp]
    public void GlobalSetup()
    {
        AppBuilder.Configure<App>()
            .UseHeadless(new AvaloniaHeadlessPlatformOptions())
            .SetupWithoutStarting();
    }

    [SetUp]
    public void Setup()
    {
        _mainWindow = new MainWindow();
    }
    
    
    // +
    [Test]
    public void AddTwoNumbers_ShouldReturnCorrectSum_WhenBothNumbersArePositive()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 3 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "+" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 4 }, null);

        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);

        ClassicAssert.AreEqual("7", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void AddTwoNumbers_ShouldReturnCorrectSum_WhenFirstNumberIsNegative()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = -3 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "+" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 4 }, null);

        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);

        ClassicAssert.AreEqual("1", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void AddTwoNumbers_ShouldReturnCorrectSum_WhenSecondNumberIsNegative()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 3 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "+" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = -4 }, null);

        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);

        ClassicAssert.AreEqual("-1", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void AddTwoNumbers_ShouldReturnCorrectSum_WhenBothNumbersAreNegative()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = -3 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "+" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = -4 }, null);

        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);

        ClassicAssert.AreEqual("-7", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void AddTwoNumbers_ShouldReturnCorrectSum_WhenOneNumberIsZero()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 0 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "+" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 4 }, null);

        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);

        ClassicAssert.AreEqual("4", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void AddTwoNumbers_ShouldReturnCorrectSum_WhenBothNumbersAreZeros()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 0 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "+" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 0 }, null);

        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);

        ClassicAssert.AreEqual("0", _mainWindow.DisplayText.Text);
    }
    
    
    //-
    [Test]
    public void SubtractTwoNumbers_ShouldReturnCorrectDifference_WhenBothNumbersArePositive()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 4 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "-" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("2", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void SubtractTwoNumbers_ShouldReturnCorrectDifference_WhenFirstNumberIsNegative()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = -4 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "-" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("-6", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void SubtractTwoNumbers_ShouldReturnCorrectDifference_WhenSecondNumberIsNegative()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 4 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "-" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = -2 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("6", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void SubtractTwoNumbers_ShouldReturnCorrectDifference_WhenBothNumbersAreNegative()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = -4 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "-" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = -2 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("-2", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void SubtractTwoNumbers_ShouldReturnCorrectDifference_WhenOneNumberIsZero()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "-" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 0 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("2", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void SubtractTwoNumbers_ShouldReturnZero_WhenBothNumbersAreEqual()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 4 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "-" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 4 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("0", _mainWindow.DisplayText.Text);
    }
    
    
    // *
    [Test]
    public void MultiplyTwoNumbers_ShouldReturnCorrectProduct_WhenBothNumbersArePositive()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "*" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("4", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void MultiplyTwoNumbers_ShouldReturnCorrectProduct_WhenFirstNumberIsNegative()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = -2 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "*" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("-4", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void MultiplyTwoNumbers_ShouldReturnCorrectProduct_WhenSecondNumberIsNegative()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "*" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = -2 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("-4", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void MultiplyTwoNumbers_ShouldReturnCorrectProduct_WhenBothNumbersAreNegative()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = -2 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "*" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = -2 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("4", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void MultiplyTwoNumbers_ShouldReturnZero_WhenOneNumberIsZero()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "*" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 0 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("0", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void MultiplyTwoNumbers_ShouldReturnZero_WhenBothNumbersAreZero()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 0 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "*" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 0 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("0", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void MultiplyTwoNumbers_ShouldReturnSameNumber_WhenMultiplyingByOne()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 8 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "*" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 1 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("8", _mainWindow.DisplayText.Text);
    }
    
    
    // "/"
    [Test]
    public void DivideTwoNumbers_ShouldReturnCorrectQuotient_WhenBothNumbersArePositive()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 4 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("2", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void DivideTwoNumbers_ShouldReturnCorrectQuotient_WhenFirstNumberIsNegative()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = -4 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("-2", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void DivideTwoNumbers_ShouldReturnCorrectQuotient_WhenSecondNumberIsNegative()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 4 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = -2 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("-2", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void DivideTwoNumbers_ShouldReturnCorrectQuotient_WhenBothNumbersAreNegative()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = -4 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = -2 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("2", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void DivideTwoNumbers_ShouldReturnOne_WhenNumberIsDividedByItself()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 4 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 4 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("1", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void DivideTwoNumbers_ShouldReturnZero_WhenZeroIsDividedByNonZeroNumber()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 0 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("0", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void DivideTwoNumbers_ShouldThrowException_WhenDividingByZero()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = "8" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "/" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = "0" }, null);
        
        var exception = Assert.Throws<DivideByZeroException>(() => 
        {
            _mainWindow.OnEqualButtonClick(new Button(), null);
        });

        Assert.That(exception.Message, Is.EqualTo("Нельзя делить на ноль!"));
    }
    
    
    // ^
    [Test]
    public void Power_ShouldReturnCorrectResult_WhenBothNumbersArePositive()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "^" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("4", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void Power_ShouldReturnOne_WhenExponentIsZero()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "^" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 0 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("1", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void Power_ShouldReturnZero_WhenBaseIsZeroAndExponentIsPositive()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 0 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "^" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("0", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void Power_ShouldReturnOne_WhenBaseIsOneRegardlessOfExponent()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 1 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "^" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 3 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("1", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void Power_ShouldReturnBase_WhenExponentIsOne()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 4 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "^" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 1 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("4", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void Power_ShouldReturnNegativeResult_WhenBaseIsNegativeAndExponentIsOdd()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = -2 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "^" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 3 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("-8", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void Power_ShouldReturnFraction_WhenExponentIsNegative()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "^" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = -3 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("0,125", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void Power_ShouldReturnCorrectResult_WhenExponentIsFractional()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 0.5 }, null);
        _mainWindow.OnOperationButtonClick(new Button { Content = "^" }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("0,25", _mainWindow.DisplayText.Text);
    }
    
    
    // sin
    [Test]
    public void Sin_ShouldReturnCorrectResult_WhenInputIsPositiveAngle()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 90 }, null);
        _mainWindow.OnSinButtonClick(new Button(), null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("1", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void Sin_ShouldReturnCorrectResult_WhenInputIsNegativeAngle()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = -90 }, null);
        _mainWindow.OnSinButtonClick(new Button(), null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("-1", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void Sin_ShouldReturnZero_WhenInputIsZero()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 0 }, null);
        _mainWindow.OnSinButtonClick(new Button(), null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("0", _mainWindow.DisplayText.Text);
    }
    
    
    // cos
    [Test]
    public void Cos_ShouldReturnCorrectResult_WhenInputIsPositiveAngle()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 360 }, null);
        _mainWindow.OnCosButtonClick(new Button(), null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("1", _mainWindow.DisplayText.Text);
    }
    
    [Test]
    public void Cos_ShouldReturnCorrectResult_WhenInputIsNegativeAngle()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = -360 }, null);
        _mainWindow.OnCosButtonClick(new Button(), null);
    
        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);
    
        ClassicAssert.AreEqual("1", _mainWindow.DisplayText.Text);
    }
    
    
    // tg
    [Test]
    public void Tg_ShouldReturnCorrectResult_WhenInputIsPositiveAngle()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 45 }, null);
        _mainWindow.OnTgButtonClick(new Button(), null);

        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);

        ClassicAssert.AreEqual("1", _mainWindow.DisplayText.Text);
    }

    [Test]
    public void Tg_ShouldReturnCorrectResult_WhenInputIsNegativeAngle()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = -45 }, null);
        _mainWindow.OnTgButtonClick(new Button(), null);

        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);

        ClassicAssert.AreEqual("-1", _mainWindow.DisplayText.Text);
    }

    [Test]
    public void Tg_ShouldReturnCorrectResult_WhenInputIsZero()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 0 }, null);
        _mainWindow.OnTgButtonClick(new Button(), null);

        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);

        ClassicAssert.AreEqual("0", _mainWindow.DisplayText.Text);
    }
    
    
    // ctg
    [Test]
    public void Ctg_ShouldReturnCorrectResult_WhenInputIsPositiveAngle()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 45 }, null);
        _mainWindow.OnCtgButtonClick(new Button(), null);

        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);

        ClassicAssert.AreEqual("1", _mainWindow.DisplayText.Text);
    }

    [Test]
    public void Ctg_ShouldReturnCorrectResult_WhenInputIsNegativeAngle()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = -45 }, null);
        _mainWindow.OnCtgButtonClick(new Button(), null);

        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);

        ClassicAssert.AreEqual("1", _mainWindow.DisplayText.Text);
    }

    [Test]
    public void Ctg_ShouldReturnCorrectResult_WhenInputIsZero()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 0 }, null);
        _mainWindow.OnCtgButtonClick(new Button(), null);

        _mainWindow.OnEqualButtonClick(new Button(), null);
        _mainWindow.OnEqualButtonClick(new Button(), null);

        ClassicAssert.AreEqual("\u221e", _mainWindow.DisplayText.Text);
    }
    
    
    // Buttons
    [Test]
    public void Buttons_ShouldReturnCorrectResult_WhenInputIsZero()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 1 }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 3 }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 4 }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 5 }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 6 }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 7 }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 8 }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 9 }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 0 }, null);

        ClassicAssert.AreEqual("1234567890", _mainWindow.DisplayText.Text);
    }
    
    
    // AC
    [Test]
    public void ClearButton_ShouldClearDisplayText_ClearButton()
    {
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
        _mainWindow.OnNumberButtonClick(new Button { Content = 2 }, null);
        
        ClassicAssert.AreEqual("22", _mainWindow.DisplayText.Text);
        
        _mainWindow.OnClearButtonClick(new Button(), null);
        
        ClassicAssert.AreEqual("0", _mainWindow.DisplayText.Text);;
    }
}