Powermock and Mockito. Avoid static initialization

Question

Suppose I have a class named Util with static fields:

public class Util {

    public static field = Param.getValue("param1");                 

}

and the class Param look like this:

public class Param {

    public static field = SomeClass.getValue("someValue");

}

I want to mock and stubb Param.getValue("param1") inside Util, but at the same time I want suppress static initialization for Param class. How can I achieve this?

This is my first attempt but it's not working

@RunWith(PowerMockRunner.class)
@PrepareForTest({Param.class})
@SuppressStaticInitializationFor("py.com.company.Param")
public class Test {

     @Test
     public void testSomeMethod() {
         PowerMockito.mockStatic(Param.class);
         when(Param.getValue("value1")).thenReturn("someValue1");
     }

}

Answer 1

This is working for me. I get no output, and SomeClass#getValue if no @SuppressStaticInitializationFor:

@RunWith(PowerMockRunner.class)
@SuppressStaticInitializationFor({"so35047166.Param"})
@PrepareForTest({Param.class})
public class UtilTest {
    @Before
    public void setUp() throws Exception {
        PowerMockito.mockStatic(Param.class);
    }

    @Test
    public void testFoo() throws Exception {
        final Util util = new Util();
        assertEquals("Util#foo", util.foo());
        assertEquals(null, Util.field);
    }
}

with:

// all in package so35047166;

public class Util {

    public static String field = Param.getValue("param1");

    public String foo() {
        return "Util#foo";
    }
}

public class Param {

    public static String field = SomeClass.getValue("someValue");

    public static String getValue(final String in) {
        System.out.println("Param#getValue");
        return "Param#getValue";
    }
}

public class SomeClass {
    public static String getValue(final String in) {
        System.out.println("SomeClass#getValue");
        return "SomeClass#getValue";
    }
}