public void AddsTwoNumbers()
{
// Arrange
var adding = new AddExpression(new ConstantExpression(1), new ConstantExpression(1));
// Act
var result = adding.Solve(new Context());
// Assert
Assert.Equal(2, result);
}
public void DoesLittleBitMoreComplicatedCalculation()
{
// Arrange
var adding = new AddExpression(new ConstantExpression(1), new ConstantExpression(1));
var subtracting = new SubtractExpression(new ConstantExpression(4), new ConstantExpression(2));
var subtractingResult = new SubtractExpression(adding, subtracting);
// Act
var result = subtractingResult.Solve(null);
// Assert
Assert.Equal(0, result);
}
public void CalculatesExpressionWithVariable()
{
// Arrange
var adding = new AddExpression(new ConstantExpression(1), new Variable("n"));
var subtracting = new SubtractExpression(new ConstantExpression(4), new Variable("n"));
var subtractingResult = new SubtractExpression(adding, subtracting);
var n = 3;
var context = new Context();
context.SetVariable("n", new ConstantExpression(n));
// Act
var result = subtractingResult.Solve(context);
// Assert
Assert.Equal((1 + n) - (4 - n), result);
Assert.Equal(3, result);
}