feat: Implement example tests for all scenarios

Relates to: BAEL-632

mockito2/src/test/java/com/baeldung/mockito/java8/ArgumentMatcherWithLambdaUnitTest.java

@@ -0,0 +1,44 @@
+package com.baeldung.mockito.java8;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.when;
+
+import java.util.Optional;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.ArgumentMatchers;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+
+public class ArgumentMatcherWithLambdaUnitTest {
+
+    @InjectMocks
+    private UnemploymentServiceImpl unemploymentService;
+    
+    @Mock
+    private JobService jobService;
+
+    @Test
+    public void whenPersonWithJob_thenIsNotEntitled() {
+        Person peter = new Person("Peter");
+        Person linda = new Person("Linda");
+        
+        JobPosition teacher = new JobPosition("Teacher");
+
+        when(jobService.findCurrentJobPosition(
+                ArgumentMatchers.argThat((p) -> p.getName().equals("Peter")))
+             ).thenReturn(Optional.of(teacher));
+        
+        assertTrue(unemploymentService.personIsEntitledToUnemploymentSupport(linda));
+        assertFalse(unemploymentService.personIsEntitledToUnemploymentSupport(peter));
+    }
+
+    @Before
+    public void init() {
+        MockitoAnnotations.initMocks(this);
+    }
+}

mockito2/src/test/java/com/baeldung/mockito/java8/ArgumentMatcherWithoutLambdaUnitTest.java

@@ -0,0 +1,55 @@
+package com.baeldung.mockito.java8;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.when;
+
+import java.util.Optional;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.ArgumentMatchers;
+import org.mockito.InjectMocks;
+import org.mockito.ArgumentMatcher;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+
+public class ArgumentMatcherWithoutLambdaUnitTest {
+    @InjectMocks
+    private UnemploymentServiceImpl unemploymentService;
+    
+    @Mock
+    private JobService jobService;
+
+    @Test
+    public void whenPersonWithJob_thenIsNotEntitled() {
+        Person peter = new Person("Peter");
+        Person linda = new Person("Linda");
+        
+        JobPosition teacher = new JobPosition("Teacher");
+
+        when(jobService.findCurrentJobPosition(
+                ArgumentMatchers.argThat(new PeterArgumentMatcher()))
+             ).thenReturn(Optional.of(teacher));
+        
+        assertTrue(unemploymentService.personIsEntitledToUnemploymentSupport(linda));
+        assertFalse(unemploymentService.personIsEntitledToUnemploymentSupport(peter));
+    }
+
+    private class PeterArgumentMatcher implements ArgumentMatcher<Person> {
+        @Override
+        public boolean matches(Person p) {
+
+            if (p.getName().equals("Peter")) {
+                return true;
+            }
+            return false;
+        }
+    }
+
+    @Before
+    public void init() {
+        MockitoAnnotations.initMocks(this);
+    }
+}

mockito2/src/test/java/com/baeldung/mockito/java8/CustomAnswerWithLambdaUnitTest.java

@@ -0,0 +1,45 @@
+package com.baeldung.mockito.java8;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.when;
+
+import java.util.stream.Stream;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+public class CustomAnswerWithLambdaUnitTest {
+    @InjectMocks
+    private UnemploymentServiceImpl unemploymentService;
+
+    @Mock
+    private JobService jobService;
+
+    @Test
+    public void whenPersonWithJobHistory_thenSearchReturnsValue() {
+        Person peter = new Person("Peter");
+
+        assertEquals("Teacher", unemploymentService.searchJob(peter, "").get().getTitle());
+    }
+
+    @Test
+    public void whenPersonWithNoJobHistory_thenSearchReturnsEmpty() {
+        Person linda = new Person("Linda");
+
+        assertFalse(unemploymentService.searchJob(linda, "").isPresent());
+    }
+
+    @Before
+    public void init() {
+        MockitoAnnotations.initMocks(this);
+
+        when(jobService.listJobs(any(Person.class))).then((i) -> {
+            return ((Person) i.getArgument(0)).getName().equals("Peter") ? Stream.<JobPosition> builder().add(new JobPosition("Teacher")).build() : Stream.empty();
+        });
+    }
+}

mockito2/src/test/java/com/baeldung/mockito/java8/CustomAnswerWithoutLambdaUnitTest.java

@@ -0,0 +1,59 @@
+package com.baeldung.mockito.java8;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.when;
+
+import java.util.stream.Stream;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.mockito.invocation.InvocationOnMock;
+import org.mockito.stubbing.Answer;
+
+
+public class CustomAnswerWithoutLambdaUnitTest {
+    @InjectMocks
+    private UnemploymentServiceImpl unemploymentService;
+    
+    @Mock
+    private JobService jobService;
+
+    @Test
+    public void whenPersonWithJobHistory_thenSearchReturnsValue() {
+        Person peter = new Person("Peter");
+        
+        assertEquals("Teacher", unemploymentService.searchJob(peter, "").get().getTitle());
+    }
+
+    @Test
+    public void whenPersonWithNoJobHistory_thenSearchReturnsEmpty() {
+        Person linda = new Person("Linda");
+
+        assertFalse(unemploymentService.searchJob(linda, "").isPresent());
+    }
+    
+    private class PersonAnswer implements Answer<Stream<JobPosition>> {
+        @Override
+        public Stream<JobPosition> answer(InvocationOnMock invocation) throws Throwable {
+            Person person = invocation.getArgument(0);
+            
+            if(person.getName().equals("Peter")) {
+                return Stream.<JobPosition>builder().add(new JobPosition("Teacher")).build();
+            } 
+            
+            return Stream.empty();
+        }
+    }
+
+    @Before
+    public void init() {
+        MockitoAnnotations.initMocks(this);
+        
+        when(jobService.listJobs(any(Person.class))).then(new PersonAnswer());
+    }
+}

mockito2/src/test/java/com/baeldung/mockito/java8/JobServiceUnitTest.java

@@ -0,0 +1,44 @@
+package com.baeldung.mockito.java8;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.doCallRealMethod;
+import static org.mockito.Mockito.when;
+
+import java.util.Optional;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+
+public class JobServiceUnitTest {
+    @Mock
+    private JobService jobService;
+
+    @Test
+    public void givenDefaultMethod_whenCallRealMethod_thenNoExceptionIsRaised() {
+        Person person = new Person();
+
+        when(jobService.findCurrentJobPosition(person)).thenReturn(Optional.of(new JobPosition()));
+        doCallRealMethod().when(jobService).assignJobPosition(Mockito.any(Person.class), Mockito.any(JobPosition.class));
+
+        assertFalse(jobService.assignJobPosition(person, new JobPosition()));
+    }
+
+    @Test
+    public void givenReturnIsOfTypeOptional_whenDefaultValueIsReturned_thenValueIsEmpty() {
+        Person person = new Person();
+
+        when(jobService.findCurrentJobPosition(person)).thenReturn(Optional.empty());
+        doCallRealMethod().when(jobService).assignJobPosition(Mockito.any(Person.class), Mockito.any(JobPosition.class));
+
+        assertTrue(jobService.assignJobPosition(person, new JobPosition()));
+    }
+
+    @Before
+    public void init() {
+        MockitoAnnotations.initMocks(this);
+    }
+}

mockito2/src/test/java/com/baeldung/mockito/java8/UnemploymentServiceImplUnitTest.java

@@ -0,0 +1,62 @@
+package com.baeldung.mockito.java8;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Matchers.any;
+import static org.mockito.Mockito.when;
+
+import java.util.Optional;
+import java.util.stream.Stream;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+public class UnemploymentServiceImplUnitTest {
+    @Mock
+    private JobService jobService;
+
+    @InjectMocks
+    private UnemploymentServiceImpl unemploymentService;
+
+    @Test
+    public void givenReturnIsOfTypeOptional_whenMocked_thenValueIsEmpty() {
+        Person person = new Person();
+
+        when(jobService.findCurrentJobPosition(any(Person.class))).thenReturn(Optional.empty());
+
+        assertTrue(unemploymentService.personIsEntitledToUnemploymentSupport(person));
+    }
+
+    @Test
+    public void givenReturnIsOfTypeOptional_whenDefaultValueIsReturned_thenValueIsEmpty() {
+        Person person = new Person();
+
+        // This will fail when Mockito 1 is used
+        assertTrue(unemploymentService.personIsEntitledToUnemploymentSupport(person));
+    }
+
+    @Test
+    public void givenReturnIsOfTypeStream_whenMocked_thenValueIsEmpty() {
+        Person person = new Person();
+
+        when(jobService.listJobs(any(Person.class))).thenReturn(Stream.empty());
+
+        assertFalse(unemploymentService.searchJob(person, "").isPresent());
+    }
+
+    @Test
+    public void givenReturnIsOfTypeStream_whenDefaultValueIsReturned_thenValueIsEmpty() {
+        Person person = new Person();
+
+        // This will fail when Mockito 1 is used
+        assertFalse(unemploymentService.searchJob(person, "").isPresent());
+    }
+
+    @Before
+    public void init() {
+        MockitoAnnotations.initMocks(this);
+    }
+}