MockFinalMethodsCases.java

package samples.powermockito.junit4.finalmocking;

import org.junit.Test;
import samples.finalmocking.FinalDemo;
import samples.privateandfinal.PrivateFinal;

import java.lang.reflect.Method;

import static org.assertj.core.api.Assertions.assertThat;
import static org.mockito.Matchers.isA;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.powermock.api.mockito.PowerMockito.doThrow;
import static org.powermock.api.mockito.PowerMockito.mock;
import static org.powermock.api.mockito.PowerMockito.spy;
import static org.powermock.api.mockito.PowerMockito.verifyPrivate;
import static org.powermock.api.mockito.PowerMockito.when;
import static org.powermock.api.support.membermodification.MemberMatcher.method;

/**
 * Cases to check mocking final non-static methods and final class
 */
public class MockFinalMethodsCases {
    @Test
    public void shouldMockFinalMethodWithNoExpectations() throws Exception {
        final String argument = "hello";

        FinalDemo tested = mock(FinalDemo.class);

        assertThat(tested.say(argument)).isNull();

        verify(tested).say(argument);
    }

    @Test
    public void shouldMockFinalMethodWithExpectations() throws Exception {
        final String argument = "hello";
        final String expected = "Hello altered World";

        FinalDemo tested = mock(FinalDemo.class);

        when(tested.say(argument)).thenReturn(expected);

        final String actual = tested.say(argument);

        verify(tested).say(argument);

        assertThat(actual).isEqualTo(expected);
    }

    @Test
    public void shouldMockFinalNativeMethodWithExpectations() throws Exception {
        final String expected = "Hello altered World";
        final String argument = "hello";

        FinalDemo tested = mock(FinalDemo.class);

        when(tested.sayFinalNative(argument)).thenReturn("Hello altered World");

        String actual = tested.sayFinalNative(argument);

        verify(tested).sayFinalNative(argument);
        assertThat(actual).isEqualTo(expected);
    }

    @Test
    public void shouldSpyingOnFinalInstanceMethod() throws Exception {
        FinalDemo tested = new FinalDemo();
        FinalDemo spy = spy(tested);

        final String argument = "PowerMock";
        final String expected = "something";

        assertThat(spy.say(argument)).isEqualTo("Hello " + argument);

        when(spy.say(argument)).thenReturn(expected);

        assertThat(spy.say(argument)).isEqualTo(expected);
    }

    @Test(expected = ArrayStoreException.class)
    public void shouldSpyingOnFinalVoidInstanceMethod() throws Exception {
        FinalDemo tested = new FinalDemo();
        FinalDemo spy = spy(tested);

        doThrow(new ArrayStoreException()).when(spy).finalVoidCallee();

        spy.finalVoidCaller();
    }

    @Test
    public void shouldSpyingOnPrivateFinalInstanceMethod() throws Exception {
        PrivateFinal spy = spy(new PrivateFinal());

        final String expected = "test";

        assertThat(spy.say(expected)).isEqualTo("Hello " + expected);

        when(spy, "sayIt", isA(String.class)).thenReturn(expected);

        assertThat(spy.say(expected)).isEqualTo(expected);

        verifyPrivate(spy, times(2)).invoke("sayIt", expected);
    }

    @Test
    public void shouldSpyingOnPrivateFinalInstanceMethodWhenUsingJavaLangReflectMethod() throws Exception {
        PrivateFinal spy = spy(new PrivateFinal());

        final String expected = "test";
        assertThat(spy.say(expected)).isEqualTo("Hello " + expected);

        final Method methodToExpect = method(PrivateFinal.class, "sayIt");
        when(spy, methodToExpect).withArguments(isA(String.class)).thenReturn(expected);

        assertThat(spy.say(expected)).isEqualTo(expected);

        verifyPrivate(spy, times(2)).invoke(methodToExpect).withArguments(expected);
    }
}