Databases
StackOverflow2013
Postsdbo
POMoq in unit Testing
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POMoq in unit Testing
    primarykey
    data
    text
    <p>Let us say I have a Service </p> <pre><code>public interface IAreaService { int CalculateArea(int x,int y); int CalculateAreaTimesX(int x, int y, int ammount); } public class AreaService : IAreaService { public int CalculateArea(int x,int y) { return x*y; } public int CalculateAreaTimesX(int x, int y, int ammount) { return CalculateArea(x, y)*ammount; } } </code></pre> <p>With the relevant Unit tests</p> <pre><code>[TestMethod] public void AreaService_GetArea_Test() { AreaService service = new AreaService(); int expected = 9; int actual = service.CalculateArea(3, 3); Assert.AreEqual(expected,actual,"The Calculate area does not work as expected"); } [TestMethod] public void AreaService_GetAreaMultiplyByX_TestTrueValue() { AreaService service = new AreaService(); int expected = 27; int actual = service.CalculateAreaTimesX(3, 3, 3); Assert.AreEqual(expected,actual); } </code></pre> <p>Ok, so after running the Unit tests. I am sure that my method in question is working and life should be great.</p> <p>But now I want to use the IAreaService in another class, and this is where i lose the light. Here is the implementation of the other class.</p> <pre><code>public class PriceCalculatorService { private readonly IAreaService _areaService; public PriceCalculatorService(IAreaService areaService) { _areaService = areaService; } public double GetPrice(int x, int y, int times, double price) { return _areaService.CalculateAreaTimesX(x, y, times)*price; } } </code></pre> <p>If I ran the following unit test (My idea might be wrong on mocking here, and this is where the question comes in.</p> <pre><code>[TestMethod] public void PriceCalculatorService_GetPrice_Test() { var IAreaServiceMock = new Mock&lt;IAreaService&gt;(); IAreaServiceMock.Setup(ism =&gt; ism.CalculateAreaTimesX(2, 2, 2)).Returns(8); PriceCalculatorService priceCalc = new PriceCalculatorService(IAreaServiceMock.Object); double expected = 20; double actual = priceCalc.GetPrice(2, 2, 2, 2.50); Assert.AreEqual(expected,actual); } </code></pre> <h1>Question</h1> <p>When i run all the unit tests mentioned above then everything is good. All of them pass. But let us say i need for some reason to change the AreaService.Calculate() method to the following </p> <pre><code>public int CalculateArea(int x,int y) { return x*y+2; } </code></pre> <p>This means that my Unit test "AreaService_GetArea_Test()" will fail, like it should, but because of the Mocking used in the "PriceCalculatorService_GetPrice_Test()" test will still pass, because it seems that when you mock a Service then the actual code is not used(obviously). So my PriceCalculatorService_GetPrice_Test is useless. But I use a stub then the unit test will fail, because it should. </p> <p>So when to Mock, and when not to Mock ?</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USKonrad Morawski
    1. USCaptain0
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POMoq in unit Testing
      1. This table or related slice is empty.
      1. VTApproveEditSuggestion
    1. COBut that's the idea of testing *units*. You are testing separate units, in isolation. Your `AreaService_GetArea_Test` will fail and that's what matters - you will see immediately which unit doesn't work properly. How would it be better if it caused a cascade of 10 fails and you'd still have to debug the whole code to identify "who's fault it is"? Wouldn't it defeat the very purpose of unit testing? :)
      singulars
      1. POMoq in unit Testing
      1. USKonrad Morawski
    2. COtrue, the light is slowly but surely coming on. It is a very big mindset change to do things this way, after you have just coded away on problems before. But I am sure it is well worth it. Thanks.
      singulars
      1. POMoq in unit Testing
      1. USCaptain0
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload