I have a DummyResource class and a DummyTarget file, and a test class TestDummyResource as below, but the mocked object DummyResource dr = mock(DummyResource.class)
DummyResource dr = mock(DummyResource.class)
You need to have prepared the class calling the constructor, not the class on which the constructor is called, the following should fix you up:
@PrepareForTest(DummyTarget.class)
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