Getting started with .NET unit testing using NUnit

It’s usually good practice to have automated unit tests while developing your code. Doing so helps you find bugs early in the development cycle and saves you time in the long run. These tests can be run by the developer multiple times to verify the behavior of a particular unit of code for different sets of input.

Unit tests essentially check the behavior of a particular unit of the code or the function, and are written by the developers who are implementing the functionalities.

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We test the behavior of a function before it becomes part of the whole system and goes to production by writing a piece of code to test this behavior under different conditions. Usually a function gets tested in isolation with the other functions of the system under test (SUT).

Read full article on the Infragistics blog

How to Unit Test Private Methods in MS Test

Before we start to see, how a private method can be unit tested using the MS Test? Let us discuss whether it is a good idea to test a private method or not? Often I have seen there are two school of thoughts,

  1. Private methods should be tested.
  2. Private methods should not be tested.

To put these things in perspective, let us consider a system under test (SUT) Salary class as shown in the listing below.

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A system under test Salary class has two functions:

  1. The CalculateSal method is a public method and it takes two parameters to calculate the salary
  2. The isValidwd method is a private method and it takes one parameter. This function returns true if the number of working days are more than 8, or else it returns false.
  3. The CalculateSal method first checks whether the number of working days is valid or not using the private method isValidWd.
  4. If the number of working days is valid, then salary is calculated by the multiplication of basic salary and the number of working days, or else it is fixed at $1000.

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TestFixtureSetUp and TestFixtureTearDown in Unit Testing using NUnit: Part 4

We have been learning Unit Testing using NUnit together. Read first three parts of this series below,

How to do Unit Test using NUnit : Part 1

Test SetUp and TearDown in Unit Testing using NUnit : Part 2

Ignore Test in Unit Testing using NUnit: Part 3

In Part 2 , we discussed about TestSetUp and TearDown. If notice TestSetUP and TearDown is related to tests. They both get executed each time a test get executed. So if there are 5 tests in Test Fixture then TestSetUp and TearDown will get executed 5 times. Sometime this is good and needed for certain requirements. However doing heavy tasks like cleaning up whole database etc. each time for a test may not be a good idea. You may want to perform certain task for whole test fixture than for each and individual tests.

You can execute certain code before execution of all the tests in test fixture by using attributing that code with [TestFixtureSetUp]. This is used to create setup for all tests at one instant.

So you can create TestFixtureSetup or setup for whole test as following,

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Basically we use TestFixtureSetUp to setup for all test. On the other hand you can clean up for all tests once using TestFixtureTearDown.

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Using TestFixtureSetUp and TestFixtureTearDown are used to set up test and clean up test. I hope you find this post useful. Thanks for reading.

Ignore Test in Unit Testing using NUnit: Part 3

We have been learning Unit Testing using NUnit together. Read first two part of this series below,

How to do Unit Test using NUnit : Part 1

Test SetUp and TearDown in Unit Testing using NUnit : Part 2

You may come across a scenario when test is itself broken. While executing test you need to ignore certain broken kind of test. Thankfully NUnit provides a very simple solution to ignore a test. By using ignore attribute you can ignore a test.

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You can ignore a unit test as following

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Let us go back to unit test we wrote in previous part of this series and modify test as following,


[Test]
 [Ignore("Ignore this test it is broken")]
 public void IsValidProductPrice()
 {

 p.ProductPrice = 100;
 if (p.ProductPrice > 0)
 {
 result = true;
 }

Assert.IsTrue(result, "Product Price is valid");

 }

On execution of test you will find that Test Runner has ignored this test. Test runner will skip test attributed with ignore.

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In this post we learnt how easily a test can be ignored in NUnit. I hope you find this post useful. Thanks for reading.

Test SetUp and TearDown in Unit Testing using NUnit : Part 2

Read Part 1 here: How to do Unit Test using NUnit : Part 1

In last post we talked about how to start with Unit Testing using NUnit. In this post I will discuss about following two topics,

  1. Test Setup
  2. Test Teardown

You need Test Setup and Test Teardown to remove any dependency between tests. Assume a scenario that

  • You want to create instance of a particular object before execution of any test
  • You want to delete a particular file from file system before execution of any test
  • You want to insert some test data or create some test data before execution of any test etc..

In above stated scenario you may want to create a Test Setup. Test Setup is a piece of code get executed before execution of any test.

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Other use case could be that you want to perform a particular task after execution of each test. So once test got executed a certain task should get done and we call that Test Teardown. There could be scenario that

  • You want to destruct an instance after execution of any test
  • You want to remove test data after execution of any test
  • You want to delete a file from file system after execution of any test etc.

In above scenario you may want to create Test Teardown. Test Teardown is piece of code get executed after execution of any test.

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In NUnit you can create Test Setup and Test Teardown by using [Setup] and [TearDown] attribute on a function.

So Test Setup can be created as following,

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And you can create Test Teardown as following

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If there are 5 tests in your test class then these two functions will get executed 5 times. Now let us put our discussion into concrete example. Assume that you are writing Unit Test for a Product class. Product class is defined as following,

namespace MyAppToTest
{
 public class Product
 {
 double productPrice;

 public double ProductPrice
 {
 get
 {
 return productPrice;
 }

set
 {
 productPrice = value;
 }
 }
 }
}

A Unit Test is written to test valid product price as following,

[Test]
 public void IsValidProductPrice()
 {

 p.ProductPrice = 100;
 if (p.ProductPrice > 0)
 {
 result = true;
 }

Assert.IsTrue(result, "Product Price is valid");
 }

You can write Test SetUp and TearDown as following,


Product p;
 bool result;
 [SetUp]
 public void TestSetup()
 {
 p = new Product();
 result = false;

 }

[TearDown]
 public void TestTearDown()
 {
 p = null;
 result = false;
 }

The above two function will get executed each time before execution of test and after execution of test. In writing Unit Test , Test SetUp and Test TearDown are very handy and useful. I hope you find this post useful. Thanks for reading.