Question

The below code is my Method logic .

pulic String getData()
{ 
if (leg.length == 4)
      return "ATE";
  else  if (leg.length == 2) {
      return "FTE";
      }
    if (leg.length == 3) {
      if (xr1.KotilaType.equals("CST")) {
        return "HTE";
      }
      return "DTE";
    }
   return "BTE";
  }

As ordered to me, i need to start writing Junit Test Cases for this Method.

As you can see there is only One method and a number of conditions inside this method .

Now my question is ,
Do we need to write a Seperate Junit TestCase ( A Seperate Method) for each condition ??

Or will it be sufficient to write only One Junit TestCase and cover all the above conditions ??

I am new to junit and not a expert , please guide me what is the approiate way for writing JunitTestCases for the above method ??

Answer 1

This is question of style. These are the two alternatives: With all in one method:

public void testAll() {
    assertEquals("ATE", getData(leg4));
    assertEquals("FTE", getData(leg2));
    // etc.
}

With one test method / combination:

public void testLength4() {
    assertEquals("ATE", getData(leg4));
}

public void testLength2() {
    assertEquals("FTE", getData(leg2));
}

The former has the advantage that it is very easy to see all combinations, because they’re all in one place. This is very useful if there are a lot of combinations or the combinations are complex.

The latter has the advantage that you have one test per combination, so it’s very easy to localize a problem, because (theoretically) only one test will fail. Disadvantage: you very quickly run out of names for test methods. testLength4, testLength2, testLength3WithCST, testLength3WithoutCST. This disadvantage gets particularly bad when you have a lot of combinations (say like one test for each month in a year).

Most of the time, I use one test method / test case, but if the number of combinations starts to get high, I would have a single method. This contains all of the combinations, because I like to be able to see all of my combinations at once, to see if I’ve missed any.