Automating unit test cases in java

Question

Referred this question first. But seems my context is different.

I'll try to be short and simple. (Just the code I'm putting out is quite big ;)

I have some 50+ service classes. And need to write the unit test cases for all of them. Across all these test classes, some tests are common. (delete, find etc) Just the object type would differ across the service classes.

Following example would clear the picture.

Consider following service class which has CRUD operations.

public class ObjService {

public Obj addObj(ParamType param, String var)  { ... }

public void deleteObj(ParamType param, String var)  { ... }

public List<Obj> findAllObj(ParamType param, String var) { ... }

public Obj findById(ParamType param, String var, String objIdToFind) { .. }

public List<Obj> getAllObjs(ParamType param, String var, ObjQuery objQuery) throws Exception { ... }

public Obj updateObj(ParamType param,
        String var, Obj objToUpdate) throws Exception { }
}

Now I'm writing a test case for ObjService class. (Test Framework - testNG)

public class ObjServiceTest {

//These methods which will differ across all service classes

@Test
public void testAddObj() throws Exception {
    addObj();
}

@Test
public void testUpdateObj() throws Exception {
    Obj objToUpdate = addObj();
    Obj updatedObj = updateObj(objToUpdate);
}

public Obj addObj() throws Exception {
    //add obj test data and return the obj object       
}

public Obj updateObj(Obj objToUpdate) throws Exception {
    //update obj test data and return the updated obj object    
}

//Following methods will be common to all classes. Except the name 'obj'
//e.g. For obj2 it would change to testDeleteObj2() { Obj2 obj2Todelete.... etc}

@Test
public void testDeleteObj() throws Exception {
    Obj objToDelete = addObj();
    deleteObj(objToDelete);
}

public void deleteObj(Obj objToDelete) throws Exception {
    //delete the obj object
}

@Test
public void testFindById() throws Exception {
    ObjService client = new ObjService();
    List<Obj> objs = dsClient.findAllObj(...);
} 

@Test
public void testFindAllObjs() throws Exception {}

@Test
public void testGetObjs() throws Exception {}
}

Now. Writing the common methods manually for all classes is surely a time consuming job. So can it be reduced by doing some automation?

(Tried my best to put the question in least baffling way)

Edit: 1) The test classes already inherit a BaseTestClass which contains the initial setup needed. So that is a problem.

2) Please don't forget the part, where refactoring is needed across the methods which differ.

Jon Skeet · Accepted Answer · 2011-02-25T17:10:42.320

It sounds like your services should implement some generic interface. That way you could write an abstract base test case which is also generic, then make each "real" service test inherit from it, including inheriting the tests within that abstract class.

The constructor for the subclass would pass in the appropriate values for things like the service, a sample query etc.

EDIT: For the base class, just make the abstract base test class subclass your existing base class.

For specialization, either override the test method itself when it needs to do a completely different thing, or make the test methods depend on abstract methods in the abstract class, so that each concrete subclass can fill in the appropriate behaviour.

Jon.Please find the edited question. Forgot to mention about the base test class. — Ravindra S, Feb 25 '11 at 17:05

score 2 · Answer 2 · answered Feb 25 '11 at 16:50

A good first step would be to make a base Test class which handles the common methods, and then derive specific Test classes from that base class to test the methods which differ per service.

You could make the base Test class a generic class which takes your service objects as a generic parameter. You may want or need to make your service classes implement a common interface, so that you can test the common methods in a consistent, type-safe manner.

score 0 · Answer 3 · answered Feb 25 '11 at 16:48

Create an abstract class that contains all tests that are common to all Services.

Include abstract method definitions for the methods that have to be implemented differently in each test class.

Now create all your test classes as subclass of this abstract class, implementing only what's needed for the individual Service.

score 0 · Answer 4 · answered Feb 25 '11 at 16:50

One possible solution could be to genericize your test cases with the object type as generic type parameter. Possibly having a generic base test class, and instantiating it with the needed concrete type(s) in each separate test subclass. I did it in a somewhat similar case and it worked out well.

Eventually, if you have much duplicated functionality to test, consider refactoring your tested classes (possibly using generics as well) to eliminate duplication. However, write the unit tests first to ensure that you aren't breaking anything during the refactoring.

Automating unit test cases in java

4 Answers4