Adding test cases

Author: onlyfullstack

unit-testing/src/main/java/com/onlyfullstack/unittesting/bean/Customer.java

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+package com.onlyfullstack.unittesting.bean;
+
+import org.apache.commons.lang3.builder.EqualsBuilder;
+import org.apache.commons.lang3.builder.HashCodeBuilder;
+
+public final class Customer {
+
+        private Integer id;
+
+        private String name;
+
+        private String address;
+
+    public Customer(Integer id, String name, String address) {
+        this.id = id;
+        this.name = name;
+        this.address = address;
+    }
+
+    @Override
+        public boolean equals(Object that) {
+        return EqualsBuilder.reflectionEquals(this, that);
+    }
+
+        @Override
+        public int hashCode()
+        {
+            return HashCodeBuilder.reflectionHashCode(this);
+        }
+
+        public Integer getId() {
+        return id;
+    }
+
+        public void setId(Integer id) {
+        this.id = id;
+    }
+
+        public String getName() {
+        return name;
+    }
+
+        public void setName(String name) {
+        this.name = name;
+    }
+
+        public String getAddress() {
+        return address;
+    }
+
+        public void setAddress(String address) {
+        this.address = address;
+    }
+
+}

unit-testing/src/main/java/com/onlyfullstack/unittesting/repository/CustomerRepository.java

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+package com.onlyfullstack.unittesting.repository;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import com.onlyfullstack.unittesting.bean.Customer;
+import org.springframework.stereotype.Component;
+
+@Component
+public class CustomerRepository {
+
+    private static Map<Integer, Customer> customerMap = new HashMap<>();
+
+    {
+        customerMap.put(1, new Customer(1, "ABC", "Pune"));
+        customerMap.put(2, new Customer(2, "XYZ", "Pune"));
+        customerMap.put(3, new Customer(3, "PQR", "Pune"));
+        customerMap.put(4, new Customer(4, "MNO", "Pune"));
+    }
+
+    public boolean saveCusomer(Customer customer) {
+        customerMap.put(customer.getId(), customer);
+        return true;
+    }
+
+    public Customer getCustomer(Integer customerId) {
+        return customerMap.get(customerId);
+    }
+
+    public void updateCustomer(Customer customer) {
+        customerMap.put(customer.getId(), customer);
+    }
+}

unit-testing/src/main/java/com/onlyfullstack/unittesting/service/CustomerService.java

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+package com.onlyfullstack.unittesting.service;
+
+import com.onlyfullstack.unittesting.bean.Customer;
+import com.onlyfullstack.unittesting.repository.CustomerRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+
+public final class CustomerService {
+
+    @Autowired
+    public CustomerRepository repository;
+
+    public boolean saveCustomer(Customer customer) {
+        if (customer == null) {
+            throw new IllegalArgumentException("Invalid Customer details passed.");
+        }
+        return repository.saveCusomer(customer);
+    }
+
+    public Customer getCustomer(Integer customerId) {
+        if (customerId == null || customerId < 0) {
+            throw new IllegalArgumentException("Invalid Customer details passed.");
+        }
+        return repository.getCustomer(customerId);
+    }
+
+    public Customer updateCustomer(Customer customer) {
+        if (customer == null || customer.getId() < 0) {
+            throw new IllegalArgumentException("Invalid Customer details passed.");
+        }
+        repository.updateCustomer(customer);
+        return customer;
+    }
+}

unit-testing/src/test/java/com/onlyfullstack/unittesting/MockVsSpy.java

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+package com.onlyfullstack.unittesting;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.Spy;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.mockito.Mockito.when;
+
+/**
+ * This class identifies the differences in between Mock and Spy
+ */
+@RunWith(MockitoJUnitRunner.class)
+public final class MockVsSpy {
+
+    /*
+     We dont need to instantiate the mock List as the @Mock will create and instantiate the list for us
+     */
+    @Mock
+    private List<String> mockedList;
+
+    /*
+    We need to instantiate the list object as the @Spy will use the real objects method if we dont mock them
+     */
+    @Spy
+    private List<String> spyList = new ArrayList();
+
+    @Test
+    public void testMockList_checkDefaultBehaviour_whenMethodIsNotMocked() {
+        /*If we dont mock the methods of @Mock object and try to call them
+        then it will not do anything.*/
+
+        mockedList.add("test"); // add the String into list which will not do anything
+        assertNull(mockedList.get(0)); // As the String was not added into the list it will return null value
+    }
+
+    @Test
+    public void testSpyList_checkDefaultBehaviour_whenMethodIsNotMocked() {
+        /* add method is not mocked so the spyList will execute
+        * the default behavoir of the add method and it will add a new String into list*/
+        spyList.add("test");
+        assertEquals("test", spyList.get(0));
+    }
+
+    @Test
+    public void testMockList_whenMethodIsMocked() {
+        /*If we dont mock the methods of @Mock object and try to call them
+        then it will not do anything.*/
+        when(mockedList.size()).thenReturn(10);
+        mockedList.add("One");
+        assertNull(mockedList.get(0)); // Again the execution of add and get methods will not have any impact on mocked object
+
+        assertEquals(10, mockedList.size()); // As the String was not added into the list it will return null value
+    }
+
+    @Test
+    public void testSpyList_whenMethodIsMocked() {
+        /* add method is not mocked so the spyList will execute
+         * the default behaviour of the add method and it will add a new String into list*/
+        when(spyList.size()).thenReturn(10);
+        spyList.add("One");
+        assertEquals("One", spyList.get(0));
+
+        assertEquals(10, spyList.size()); // size method will return 10 as we have mocked its implementation
+    }
+
+}

unit-testing/src/test/java/com/onlyfullstack/unittesting/service/CustomerServiceTest.java

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+package com.onlyfullstack.unittesting.service;
+
+import com.onlyfullstack.unittesting.bean.Customer;
+import com.onlyfullstack.unittesting.repository.CustomerRepository;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.eq;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
+import static org.mockito.Mockito.when;
+
+/**
+ * This class contains usage of Mockito
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class CustomerServiceTest {
+
+    @Mock
+    CustomerRepository repository;
+
+    @InjectMocks
+    CustomerService customerService;
+
+    @Test
+    public void saveCustomer_withValidCustomer_when_thenReturn() {
+        Customer customer = new Customer(6, "QQQ", "Mumbai");
+        when(repository.saveCusomer(any())).thenReturn(true);
+        Boolean save = customerService.saveCustomer(customer);
+        assertThat(true, is(save));
+        verify(repository, times(1)).saveCusomer(eq(customer));
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void saveCustomer_withValidCustomer_when_thenThrow() {
+        Customer customer = new Customer(6, "QQQ", "Mumbai");
+        when(repository.saveCusomer(any())).thenThrow(new IllegalStateException());
+        customerService.saveCustomer(customer);
+        verifyNoMoreInteractions();
+    }
+
+    @Test
+    public void updateCustomer_doAnswer_when() {
+        Customer customer = new Customer(6, "QQQ", "Mumbai");
+        doAnswer((arguments) -> {
+            System.out.println("Inside doAnswer block");
+            assertEquals(customer, arguments.getArgument(0));
+            return null;
+        }).when(repository).updateCustomer(any(Customer.class));
+        customerService.updateCustomer(customer);
+    }
+
+    @Test(expected = Exception.class)
+    public void updateCustomer_doNothing_when() {
+        Customer customer = new Customer(6, "QQQ", "Mumbai");
+        doThrow(new Exception("Database connection issue")).when(repository).updateCustomer(any(Customer.class));
+        customerService.updateCustomer(customer);
+    }
+}