Helper class for testing struts2 actions. The static block does the minimum wiring to avoid getText to crash. The inject method is helpful for injecting parameters to the tested action.

ActionTestHelper.java

import static org.mockito.Matchers.any;

import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

import java.lang.reflect.InvocationTargetException;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

import javax.servlet.ServletContext;

import org.apache.commons.beanutils.BeanUtils;
import org.apache.struts2.ServletActionContext;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;
import org.springframework.util.Assert;

import uk.ltd.getahead.dwr.util.Logger;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.conversion.impl.XWorkConverter;
import com.opensymphony.xwork2.inject.Container;
import com.opensymphony.xwork2.util.ValueStack;

import eu.ec.eso.varo.action.ActionBase;


/**
 * Helper class for testing struts2 actions. The static block does the minimum wiring
 * to avoid getText to crash. The inject method is helpful for injecting parameters 
 * to the tested action
 */
@SuppressWarnings("unchecked")
public class ActionTestHelper {
	private final static Logger log = Logger.getLogger(ActionTestHelper.class);
	static {
		ActionContext actionContext = mock(ActionContext.class);
		ServletContext servletContext = mock(ServletContext.class);
		when(actionContext.getLocale()).thenReturn(Locale.FRENCH);
		ValueStack valueStack = mock(ValueStack.class);
		Map<String, Object> context = new HashMap<String,Object>();
		Container container = mock(Container.class);
		XWorkConverter conv = mock(XWorkConverter.class);
		when(container.getInstance(XWorkConverter.class)).thenReturn(conv);
		when(conv.convertValue(any(Map.class), any(Object.class), any(Class.class))).thenAnswer(new Answer<Object>() {
			public Object answer(InvocationOnMock invocation) throws Throwable {
				log.info(invocation.getArguments()[1].toString());
				return "VALUE";
			}
			
		});
		context.put(ActionContext.CONTAINER, container);
		when(valueStack.getContext()).thenReturn(context);
		when(actionContext.getValueStack()).thenReturn(valueStack);
		ServletActionContext.setContext(actionContext);
		ServletActionContext.setServletContext(servletContext);
	}
	public static void inject(ActionBase action, Object... args) throws IllegalAccessException, InvocationTargetException {
		Assert.notNull(action);
		Assert.notNull(args);
		Assert.notEmpty(args);
		Assert.isTrue(args.length%2==0, "You should have an even number of arguments after the action.");
		
		for (int i=0; i<args.length; i=i+2) {
			Assert.isTrue(String.class.isInstance(args[i]), String.format("Argument %1$d should be a string", i));
			BeanUtils.setProperty(action, (String)args[i], args[i+1]);
		}
	}
}

where is the code for the eu.ec.eso.varo.action.ActionBase?

Excelente idea!