PowerMockito.whenNew isn't working

Question

Update. Check working example in the end.

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I've got a class:

package test;

public class ClassXYZ {
    private final String message;

    public ClassXYZ() {
        this.message = "";
    }

    public ClassXYZ(String message) {
        this.message = message;
    }

    @Override
    public String toString() {
        return "ClassXYZ{" + message + "}";
    }
}

and a test:

package test;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.modules.junit4.PowerMockRunner;

@RunWith(PowerMockRunner.class)
public class MockClassXYZ {

    @Test
    public void test() throws Exception {
        PowerMockito.whenNew(ClassXYZ.class).withNoArguments().thenReturn(new ClassXYZ("XYZ"));

        System.out.println(new ClassXYZ());
    }
}

but it still creates a real class and prints:

ClassXYZ{}

What am I doing wrong?

P.S. Maven deps:

<dependencies>
    <dependency>
        <groupId>org.powermock</groupId>
        <artifactId>powermock-module-junit4</artifactId>
        <version>1.5.6</version>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>org.powermock</groupId>
        <artifactId>powermock-api-mockito</artifactId>
        <version>1.5.6</version>
        <scope>test</scope>
    </dependency>
</dependencies>

---

Working example:

package test;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

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

@RunWith(PowerMockRunner.class)
@PrepareForTest(ClassXYZ.class)
public class MockClassXYZ {
    @Test
    public void test() throws Exception {
        ClassXYZ mockXYZ = mock(ClassXYZ.class);
        when(mockXYZ.toString()).thenReturn("XYZ");

        PowerMockito.whenNew(ClassXYZ.class).withNoArguments().thenReturn(mockXYZ);

        ClassXYZ obj = new ClassXYZ();
        System.out.println(obj);
    }
}

Answer 1

You are missing a @PrepareForTest(ClassXYZ.class) on your test class, see the documentation here or here. From the first link:

Mock construction of new objects

Quick summary

1. Use the @RunWith(PowerMockRunner.class) annotation at the class-level of the test case.
2. Use the @PrepareForTest(ClassThatCreatesTheNewInstance.class) annotation at the class-level of the test case.

[...]

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Also note that there's no point of mocking the constructor if you ask the mocking framework to return a real instance of the mocked class.