Hello, How would I test this in Junit? Is there anything else I can do with...

I would share you some snapshots from one of existing project to show how junit can be applied successfully

So this is the general structure of the project and the imports you would need .

You can multiple test cases like

   @Test
   public void testGetCook() {
      
       cook = cookDAO.get(3);
      
      
       assertEquals("Successfully fetched a single cook from the table!","Television",cook.getName());
      
      
   }
  
  
   @Test
   public void testUpdateCook() {
      
       cook = cookDAO.get(3);
      
       cook.setName("TV");
      
       assertEquals("Successfully updated a single cook in the table!",true,cookDAO.update(cook));
      
      
   }
  

This code is from the same file . the important line is the assertEquals for you . So if the update has been successfull then the test case pass .

After that you need to write click on the file and Run As --> Junit .

So for your example , you need to run the test case on your methods for example .

private double calculateTax(double gross){
double federalTax = gross*FEDERAL_TAX_RATE;
double stateTax = gross*STATE_TAX_RATE;
return federalTax+stateTax;
}

assertEquals("Successfully calculated test",expectedvalue,calculateTax(100.00));

@Test
   public void testUpdateCook() {
      
// Create the PayCalculator object here.
  assertEquals("Successfully calculated test",expectedvalue,obj.calculateTax(100.00));
      
      
   }

Hope this helps.