IntelliJ IDEA for unit testing

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 Please read the previous post if you haven't, Previous (Java Unit Testing with JUnit ).

 We are performing the same test but using IDE. And download IntelliJ IDEA if you haven't.

For this unit testing, i have created new project, no libraries, no template.

1. Create new directory "test", right click on project > add > directory.
   
2. Mark the directory as test sources root.
   
3. Create Calculator class, the class is created as , right click on project > add > java class.
   paste the code
   
   

   public class Calculator{
   
       // default values
       double p = 0.0;
       double t = 0.0;
       double r = 0.0;
   
       // constructor that updates the values
       public Calculator(double p, double t, double r){
           this.p = p;
           this.t = t;
           this.r = r;
       }
   
       // method that calculates the interest
       public double calculateInterest(){
           return p*t*r / 100;
       }
   }
   

4. Create test class for Calculator, press alt & enter on class name > create test.
   
   
   Configure JUnit like as this
   
   Fix and download library
   
   And the newly created testClass (CalculatorTest) will look like this 
   

   import org.junit.After;
   import org.junit.Before;
   import org.junit.Test;
   
   import static org.junit.Assert.*;
   
   public class CalculatorTest {
   
       Calculator calculator = null;
   
       // values for your test case
       double p = 10000.0;
       double t = 1.0;
       double r = 10.0;
   
       @Before
       public void setUp() throws Exception {
           calculator = new Calculator(p, t, r);
       }
   
       @After
       public void tearDown() throws Exception {
       }
   
       @Test
       public void calculateInterest() {
           assertEquals(1000.0, calculator.calculateInterest(), 0.0);
       }
   }
   

5. Create a TestRunner class inside test directory. This will be our entry point to perform all test, paste.
   
   

   import org.junit.runner.JUnitCore;
   import org.junit.runner.Result;
   import org.junit.runner.notification.Failure;
   
   public class TestRunner{
   
       public static void main(String[] str){
   
           // Run test classes and grab result
           Result result = JUnitCore.runClasses(CalculatorTest.class);
   
           // Test result
           System.out.println(result.wasSuccessful());
   
           // print the failure message if failure
           for(Failure failure : result.getFailures()){
               // print string
               System.out.println(failure.toString());
           }
   
       }
   }
   

6. Yey, test success.
   

References:

1. https://www.jetbrains.com/help/idea/configuring-testing-libraries.html