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C# Unit Testing in C# Test Driven Development TDD

Posted by mjmj
mjmj
18,664 Points

Challenge Task 4 of 4, Implement the Subtract method so that the test passes. Not passing.

Code not passing, some silly mistake cannot find.

Calculator.cs 
public class Calculator
{
    public double Result;

    public Calculator(double number)
    {
        Result = number;
    }     

    public void Add(double number)
    {
        Result += number;
    }

    public void Substract(double number)
    {
        Result -= number;
    }
}
CalculatorTests.cs 
using Xunit;

public class CalculatorTests
{
    [Fact]
    public void Initialization()
    {
        var expected = 1.1;
        var target = new Calculator(1.1);
        Assert.Equal(expected, target.Result, 1);
    }

    [Fact]
    public void BasicAdd()
    {
        var target = new Calculator(1.1);
        target.Add(2.2);
        var expected = 3.3;
        Assert.Equal(expected, target.Result, 1);
    }

    [Fact]
    public void BasicSubtract()
    {
        var target = new Calculator(1.1);
        target.Substract(0.2);
        var expected = 0.9;
        Assert.Equal((); target.Result >= 0.9);
    }
}

1 Answer

Jeff Wilton
Jeff Wilton
16,646 Points
Jeff Wilton
Jeff Wilton
16,646 Points

There is a typo in the name of the Subtract method. Other than that, the test should look like this:

[Fact]
    public void BasicSubtract()
    {
        var target = new Calculator(1.1);
        target.Subtract(0.2);
        var expected = 0.9;
        Assert.Equal(expected, target.Result, 1);
    }
Steven Parker
Steven Parker
231,236 Points
Steven Parker
Steven Parker
231,236 Points

And don't forget that the same spelling in "calculator.js" will also need to be changed.

mjmj
mjmj
18,664 Points

Thank you.