I have a class as below
public Class CLZA {
private Object obj1;
private Object obj2;
private StringBuilder strBuilder;
public CLZA (CLZB objB) {
obj1 = objB.fetchValueOfObj(Request.type1);
obj2 = objB.fetchValueOfObj(Request.type2);
strBuilder = new StringBuilder();
}
public double computeValue(...) {
if (this.obj1 == 1.0) {
...
}
if (this.obj2 == 2.0) {
...
}
strBuilder.append("This is the line I got NPE now");
}
}
Right now, I am trying to do something like this.
@RunWith(PowerMockRunner.class)
@PrepareForTest({CLZA.class, StringBuilder.class})
public class ClzATest {
private CLZA objA;
@Mock
private CLZB objB;
@Before
public void setUp() throws Exception {
objA = new CLZA(objB);
when(objB.fetchValueOfObj(any(Request.class))).thenAnswer(
invocation -> {
Object argument = invocation.getArguments()[0];
if (argument.equals(Request.type1)) {
return 1.0;
} else if (argument.equals(Request.type2)) {
return 2.0;
} else {
return 0.0;
}
});
}
@Test
public void testComputeValue() {
double value = objA.computeValue(...);
assertEquals(2.0, value);
}
}
I have following questions/issues:
As you can see, I want to mock the value of the objB returned. Can I pass the mocked objB to the constructor when I instantiate the Class CLZA? should I mock CLZA also? If I need to mock CLZA, how can I related it to my mocked objB?
Right now, I keep getting NullPointerException at the line
strBuilder.append("This is the line I got NPE now");. It seems strBuilder is not instantiated. Can anyone help on how to test in this scenario?
Appreciate it.
