You can create a listener implementing IMethodInterceptor interface. Which will give you an ability to access groups list from your @Test and manage your "tests to execute list" as you need. At same time ITestContext parameter allows you to access the data from testNg xml. So, you can set groups to run in default testNg manner (suite xml file); but run them depending on algorithm you implement. Something like:
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.testng.IMethodInstance;
import org.testng.IMethodInterceptor;
import org.testng.ITestContext;
import org.testng.annotations.Test;
public class Interceptor implements IMethodInterceptor
{
@Override
public List<IMethodInstance> intercept(List<IMethodInstance> methods, ITestContext context)
{
int methCount = methods.size();
List<IMethodInstance> result = new ArrayList<IMethodInstance>();
for (int i = 0; i < methCount; i++)
{
IMethodInstance instns = methods.get(i);
List<String> grps = Arrays.asList(instns.getMethod().getConstructorOrMethod().getMethod().getAnnotation(Test.class).groups());
//get these groups from testng.xml via context method parameter
if (grps.contains("A") && grps.contains("B"))
{
result.add(instns);
}
}
return result;
}
}