# Visual Basic .NET Language Unit Testing for Tax Calculation

## Example

This example is divided into two pillars

• SalaryCalculation Class : Calculating the net salary after tax deduction
• SalaryCalculationTests Class : For testing the method that calculates the net salary

Step 1: Create Class Library, name it WagesLibrary or any appropriate name. Then rename the class to SalaryCalculation

''' ''' Class for Salary Calculations ''' Public Class SalaryCalculation

``````    ''' <summary>
''' Employee Salary
''' </summary>
Public Shared Salary As Double

''' <summary>
''' Tax fraction (0-1)
''' </summary>
Public Shared Tax As Double

''' <summary>
''' Function to calculate Net Salary
''' </summary>
''' <returns></returns>
Public Shared Function CalculateNetSalary()
Return Salary - Salary * Tax
End Function
End Class
``````

Step 2 : Create Unit Test Project. Add reference to the created class library and paste the below code

``````Imports WagesLibrary 'Class library you want to test

''' <summary>
''' Test class for testing SalaryCalculation
''' </summary>
<TestClass()> Public Class SalaryCalculationTests

''' <summary>
''' Test case for the method CalculateNetSalary
''' </summary>
<TestMethod()> Public Sub CalculateNetSalaryTest()
SalaryCalculation.Salary = 100
SalaryCalculation.Tax = 0.1
Assert.AreEqual(90.0, SalaryCalculation.CalculateNetSalary(), 0.1)
End Sub
End Class
``````

`Assert.Equal` checks the expected value against the actual calculated value. the value `0.1` is used to allow tolerance or variation between expected and actual result.

Step 3 : Run the test of the method to see result  PDF - Download Visual Basic .NET Language for free