public void PlusMinusPositiveTest()
{
calculator.Number("9");
calculator.Number("0");
Assert.AreEqual("90", calculator.Input);
calculator.PlusMinus();
Assert.AreEqual("-90", calculator.Input);
}
/// <summary>
/// Processes plusMinus's click
/// </summary>
private void PlusMinus_Click(object sender, EventArgs e)
{
calculator.PlusMinus();
}
