I'm having hard time to test a class(TestClass) which uses builder pattern(BuilderClass) in logic . I'm unable to mock builder class(BuilderClass). The following is simplified version of my logic.
public class TestClass {
public int methodA() {
ExternalDependency e = BuilerClass.builder().withName("xyz").withNumber(10).build();
return e.callExternalFunction();
}
}
And here is my builder class
public class BuilderClass {
public static BuilderClass builder() { return new BuilderClass(); }
int number;
String name;
public BuilderClass withName(String name) {
this.name = name;
return this;
}
public BuilderClass withNumber(int number) {
this.number = number;
return this;
}
public ExternalDependency build() {
return new ExternalDependency(name,number);
}
}
For my test class, I'm using Mockito with Dataprovider.
@RunWith(DataProviderRunner.class)
class TestClassTest {
@Mock private ExternalDependency e;
@Mock private BuilderClass b;
@InjectMocks private TestClass t;
@Before public void setUp() { MockitoAnnotations.initMocks(this); }
@Test public void testMethodA() {
when(b.withName(any(String.class)).thenReturn(b); //This is not mocking
when(b.withNumber(10)).thenReturn(b); //This is not mocking
Assert.notNull(this.t.methodA()); //Control while execution is going to implementation of withName and withNumber, which should not happen right.
}
Help me if I miss anything. Thanks }