Writing test case for switch statement inside private method

Question

I have a switch case statement inside a private method. I don't think we need to do unit testing for the private method. But my code coverage tool(EclEmma) is showing "1 of 4 branches missed." with yellow diamond on switch statement. So my question is: how I can write test for this particular situation?

Code Snippet

public void parentMethod() {
  ....
  childMethod(someList);
  ....
} 

private void childMethod(List<Integer> someList) {
  for(Integer var : someList) {
    switch(var){ ..... }
  }
}

With test cases for the public method that exercise all code paths of the private method. — Oliver Charlesworth, Sep 26 '14 at 17:57
How do you send / set your var that is the switch case variable? — StackFlowed, Sep 26 '14 at 17:57
http://emma.sourceforge.net/faq.html#q.fractional.examples may be helpful. — Carl Manaster, Sep 26 '14 at 18:44

Alexey Semenyuk · Accepted Answer · 2014-09-26T18:40:45.347

So, you can try to use reflection, something like this:

MyClass myClass = new MyClass();  
List<Integer> input = Arrays.asList(1, 2, 3);

Method method = MyClass.class.getDeclaredMethod("childMethod", List.class);
method.setAccessible(true);
method.invoke(myClass, input);
....

Good links about approachs for testing private methods or not testing in general:

http://saturnboy.com/2010/11/testing-private-methods-in-java/

http://www.artima.com/suiterunner/privateP.html

Writing test case for switch statement inside private method

1 Answers1