What You Will Learn during this Step:

Add dependency on PowerMock.
Using PowerMock and Mockito to mock a Static Method.
PowerMockitoMockingStaticMethodTest

Useful Snippets and References

pom.xml

		<dependency>
			<groupId>org.powermock</groupId>
			<artifactId>powermock-api-mockito</artifactId>
			<version>1.6.4</version>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.powermock</groupId>
			<artifactId>powermock-module-junit4</artifactId>
			<version>1.6.4</version>
			<scope>test</scope>
		</dependency>

Other Useful Snippets

@RunWith(PowerMockRunner.class)
@PrepareForTest({ UtilityClass.class})

PowerMockito.mockStatic(UtilityClass.class);
when(UtilityClass.staticMethod(anyLong())).thenReturn(150);

PowerMockito.verifyStatic();
UtilityClass.staticMethod(1 + 2 + 3);

Files List

/pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>com.in28minutes.mockito</groupId>
	<artifactId>mockito-tutorial</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<dependencies>
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.12</version>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.mockito</groupId>
			<artifactId>mockito-all</artifactId>
			<version>1.10.19</version>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.hamcrest</groupId>
			<artifactId>hamcrest-library</artifactId>
			<version>1.3</version>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.powermock</groupId>
			<artifactId>powermock-api-mockito</artifactId>
			<version>1.6.4</version>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.powermock</groupId>
			<artifactId>powermock-module-junit4</artifactId>
			<version>1.6.4</version>
			<scope>test</scope>
		</dependency>
	</dependencies>
	<build>
		<plugins>
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-compiler-plugin</artifactId>
				<configuration>
					<source>1.8</source>
					<target>1.8</target>
				</configuration>
			</plugin>
		</plugins>
	</build>
</project>

/src/main/java/com/in28minutes/business/TodoBusinessImpl.java

package com.in28minutes.business;

import java.util.ArrayList;
import java.util.List;

import com.in28minutes.data.api.TodoService;

public class TodoBusinessImpl {

	private TodoService todoService;

	TodoBusinessImpl(TodoService todoService) {
		this.todoService = todoService;
	}

	public List<String> retrieveTodosRelatedToSpring(String user) {
		List<String> filteredTodos = new ArrayList<String>();
		List<String> allTodos = todoService.retrieveTodos(user);
		for (String todo : allTodos) {
			if (todo.contains("Spring")) {
				filteredTodos.add(todo);
			}
		}
		return filteredTodos;
	}

	public void deleteTodosNotRelatedToSpring(String user) {
		List<String> allTodos = todoService.retrieveTodos(user);
		for (String todo : allTodos) {
			if (!todo.contains("Spring")) {
				todoService.deleteTodo(todo);
			}
		}
	}
}

/src/main/java/com/in28minutes/data/api/TodoService.java

package com.in28minutes.data.api;

import java.util.List;

// External Service - Lets say this comes from WunderList
public interface TodoService {

	public List<String> retrieveTodos(String user);

	void deleteTodo(String todo);

}

/src/main/java/com/in28minutes/junit/business/ClientBO.java

package com.in28minutes.junit.business;

import java.util.List;

import com.in28minutes.junit.business.exception.DifferentCurrenciesException;
import com.in28minutes.junit.model.Amount;
import com.in28minutes.junit.model.Product;

public interface ClientBO {

	Amount getClientProductsSum(List<Product> products)
			throws DifferentCurrenciesException;

}

/src/main/java/com/in28minutes/junit/business/ClientBOImpl.java

package com.in28minutes.junit.business;

import java.math.BigDecimal;
import java.util.List;

import com.in28minutes.junit.business.exception.DifferentCurrenciesException;
import com.in28minutes.junit.model.Amount;
import com.in28minutes.junit.model.AmountImpl;
import com.in28minutes.junit.model.Currency;
import com.in28minutes.junit.model.Product;

public class ClientBOImpl implements ClientBO {

	public Amount getClientProductsSum(List<Product> products)
			throws DifferentCurrenciesException {

		if (products.size() == 0)
			return new AmountImpl(BigDecimal.ZERO, Currency.EURO);

		if (!isCurrencySameForAllProducts(products)) {
			throw new DifferentCurrenciesException();
		}

		BigDecimal productSum = calculateProductSum(products);

		Currency firstProductCurrency = products.get(0).getAmount()
				.getCurrency();

		return new AmountImpl(productSum, firstProductCurrency);
	}

	private BigDecimal calculateProductSum(List<Product> products) {
		BigDecimal sum = BigDecimal.ZERO;
		// Calculate Sum of Products
		for (Product product : products) {
			sum = sum.add(product.getAmount().getValue());
		}
		return sum;
	}

	private boolean isCurrencySameForAllProducts(List<Product> products)
			throws DifferentCurrenciesException {

		Currency firstProductCurrency = products.get(0).getAmount()
				.getCurrency();

		for (Product product : products) {
			boolean currencySameAsFirstProduct = product.getAmount()
					.getCurrency().equals(firstProductCurrency);
			if (!currencySameAsFirstProduct) {
				return false;
			}
		}

		return true;
	}
}

/src/main/java/com/in28minutes/junit/business/exception/DifferentCurrenciesException.java

package com.in28minutes.junit.business.exception;

public class DifferentCurrenciesException extends Exception {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

}

/src/main/java/com/in28minutes/junit/helper/StringHelper.java

package com.in28minutes.junit.helper;

public class StringHelper {

	public String truncateAInFirst2Positions(String str) {
		if (str.length() <= 2)
			return str.replaceAll("A", "");

		String first2Chars = str.substring(0, 2);
		String stringMinusFirst2Chars = str.substring(2);

		return first2Chars.replaceAll("A", "") + stringMinusFirst2Chars;
	}
	
	public boolean areFirstAndLastTwoCharactersTheSame(String str) {

		if (str.length() <= 1)
			return false;
		if (str.length() == 2)
			return true;

		String first2Chars = str.substring(0, 2);

		String last2Chars = str.substring(str.length() - 2);

		return first2Chars.equals(last2Chars);
	}

}

/src/main/java/com/in28minutes/junit/model/Amount.java

package com.in28minutes.junit.model;

import java.math.BigDecimal;

public interface Amount {
	BigDecimal getValue();

	Currency getCurrency();
}

/src/main/java/com/in28minutes/junit/model/AmountImpl.java

package com.in28minutes.junit.model;

import java.math.BigDecimal;

public class AmountImpl implements Amount {

	BigDecimal value;
	Currency currency;

	public AmountImpl(BigDecimal value, Currency currency) {
		super();
		this.value = value;
		this.currency = currency;
	}

	public void setValue(BigDecimal value) {
		this.value = value;
	}

	@Override
	public BigDecimal getValue() {
		return value;
	}

	public void setCurrency(Currency currency) {
		this.currency = currency;
	}

	@Override
	public Currency getCurrency() {
		return currency;
	}

}

/src/main/java/com/in28minutes/junit/model/Client.java

package com.in28minutes.junit.model;

import java.math.BigDecimal;
import java.util.List;

/**
 * Client Model API.
 */
public interface Client {

	long getId();

	String getName();

	Enum<?> getType();

	List<Collateral> getCollaterals();

	List<Product> getProducts();

	void setProductAmount(BigDecimal productAmount);

	BigDecimal getProductAmount();

}

/src/main/java/com/in28minutes/junit/model/ClientImpl.java

package com.in28minutes.junit.model;

import java.math.BigDecimal;
import java.util.List;

/**
 * Client Model API.
 */
public class ClientImpl implements Client {

	private long id;

	private String name;

	private ClientType type;

	private List<Collateral> collaterals;

	private List<Product> products;

	private BigDecimal productAmount;

	public ClientImpl(long id, String name, ClientType type,
			List<Collateral> collaterals, List<Product> products) {
		super();
		this.id = id;
		this.name = name;
		this.type = type;
		this.collaterals = collaterals;
		this.products = products;
	}

	public long getId() {
		return id;
	}

	public void setId(long id) {
		this.id = id;
	}

	@Override
	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	@Override
	public ClientType getType() {
		return type;
	}

	public void setType(ClientType type) {
		this.type = type;
	}

	@Override
	public List<Collateral> getCollaterals() {
		return collaterals;
	}

	public void setCollaterals(List<Collateral> collaterals) {
		this.collaterals = collaterals;
	}

	@Override
	public List<Product> getProducts() {
		return products;
	}

	public void setProducts(List<Product> products) {
		this.products = products;
	}

	@Override
	public BigDecimal getProductAmount() {
		return productAmount;
	}

	@Override
	public void setProductAmount(BigDecimal productAmount) {
		this.productAmount = productAmount;
	}

}

/src/main/java/com/in28minutes/junit/model/ClientType.java

package com.in28minutes.junit.model;

import java.util.Arrays;
import java.util.List;

/**
 * Available types of customers
 */
public enum ClientType {
	/**
     * 
     */
	PRIVATE("P"),
	/**
     * 
     */
	BUSINESS("Z");

	private final String textValue;

	/**
	 * List of natural person types.
	 */
	public static final List<String> NATURAL_PERSON_TYPES = Arrays
			.asList(ClientType.PRIVATE.toString());

	/**
	 * List of corporate types.
	 */
	public static final List<String> CORPORATE_TYPES = Arrays
			.asList(ClientType.BUSINESS.toString());

	ClientType(final String textValue) {
		this.textValue = textValue;
	}

	@Override
	public String toString() {
		return textValue;
	}
}

/src/main/java/com/in28minutes/junit/model/Collateral.java

package com.in28minutes.junit.model;

/**
 * Collateral Model API.
 */
public interface Collateral {

	long getId();

	String getName();

	CollateralType getType();
}

/src/main/java/com/in28minutes/junit/model/CollateralImpl.java

package com.in28minutes.junit.model;

/**
 * Collateral Model Object.
 */
public class CollateralImpl implements Collateral {

	private long id;

	private String name;

	private CollateralType type;

	public CollateralImpl(long id, String name, CollateralType type) {
		super();
		this.id = id;
		this.name = name;
		this.type = type;
	}

	public long getId() {
		return id;
	}

	public void setId(long id) {
		this.id = id;
	}

	@Override
	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	@Override
	public CollateralType getType() {
		return type;
	}

	public void setType(CollateralType type) {
		this.type = type;
	}
}

/src/main/java/com/in28minutes/junit/model/CollateralType.java

package com.in28minutes.junit.model;

import java.util.Arrays;
import java.util.List;

/**
 * Available types of customers
 */
public enum CollateralType {
	REAL_ESTATE("REA"), BONDS("BND"), MUTUAL_FUNDS("MFD"), STOCKS("STK");

	private final String textValue;

	/**
	 * All collateral types classified as securities.
	 */
	public static final List<CollateralType> SECURITIES = Arrays.asList(BONDS,
			MUTUAL_FUNDS, STOCKS);

	CollateralType(final String textValue) {
		this.textValue = textValue;
	}

	@Override
	public String toString() {
		return textValue;
	}
}

/src/main/java/com/in28minutes/junit/model/Currency.java

package com.in28minutes.junit.model;

public enum Currency {

	EURO("EUR"), UNITED_STATES_DOLLAR("USD"), INDIAN_RUPEE("INR");

	private final String textValue;

	Currency(final String textValue) {
		this.textValue = textValue;
	}

	@Override
	public String toString() {
		return textValue;
	}
}

/src/main/java/com/in28minutes/junit/model/Product.java

package com.in28minutes.junit.model;

/**
 * Product Model API.
 */
public interface Product {

	long getId();

	String getName();

	ProductType getType();

	Amount getAmount();
}

/src/main/java/com/in28minutes/junit/model/ProductImpl.java

package com.in28minutes.junit.model;

/**
 * Collateral Model Object.
 */
public class ProductImpl implements Product {

	private long id;

	private String name;

	private ProductType type;

	private Amount amount;

	public ProductImpl(long id, String name, ProductType type, Amount amount) {
		super();
		this.id = id;
		this.name = name;
		this.type = type;
		this.amount = amount;
	}

	@Override
	public long getId() {
		return id;
	}

	public void setId(long id) {
		this.id = id;
	}

	@Override
	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	@Override
	public ProductType getType() {
		return type;
	}

	public void setType(ProductType type) {
		this.type = type;
	}

	@Override
	public Amount getAmount() {
		return amount;
	}

	public void setAmount(Amount amount) {
		this.amount = amount;
	}
}

/src/main/java/com/in28minutes/junit/model/ProductType.java

package com.in28minutes.junit.model;

/**
 * Available types of customers
 */
public enum ProductType {
	LOAN("LN"), KREDIT("KRD"), BANK_GUARANTEE("BG");

	private final String textValue;

	ProductType(final String textValue) {
		this.textValue = textValue;
	}

	@Override
	public String toString() {
		return textValue;
	}
}

/src/main/java/com/in28minutes/powermock/SystemUnderTest.java

package com.in28minutes.powermock;

import java.util.ArrayList;
import java.util.List;

interface Dependency {
	List<Integer> retrieveAllStats();
}

public class SystemUnderTest {
	private Dependency dependency;

	public int methodUsingAnArrayListConstructor() {
		ArrayList list = new ArrayList();
		return list.size();
	}

	public int methodCallingAStaticMethod() {
		//privateMethodUnderTest calls static method SomeClass.staticMethod
		List<Integer> stats = dependency.retrieveAllStats();
		long sum = 0;
		for (int stat : stats)
			sum += stat;
		return UtilityClass.staticMethod(sum);
	}

	private long privateMethodUnderTest() {
		List<Integer> stats = dependency.retrieveAllStats();
		long sum = 0;
		for (int stat : stats)
			sum += stat;
		return sum;
	}
}

/src/main/java/com/in28minutes/powermock/UtilityClass.java

package com.in28minutes.powermock;

public class UtilityClass {
	static int staticMethod(long value) {
		// Some complex logic is done here...
		throw new RuntimeException(
				"I dont want to be executed. I will anyway be mocked out.");
	}
}

/src/test/java/com/clarity/business/ClientBOTest.java

package com.clarity.business;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;

import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.List;

import org.junit.Test;

import com.in28minutes.junit.business.ClientBO;
import com.in28minutes.junit.business.ClientBOImpl;
import com.in28minutes.junit.business.exception.DifferentCurrenciesException;
import com.in28minutes.junit.model.Amount;
import com.in28minutes.junit.model.AmountImpl;
import com.in28minutes.junit.model.Currency;
import com.in28minutes.junit.model.Product;
import com.in28minutes.junit.model.ProductImpl;
import com.in28minutes.junit.model.ProductType;

public class ClientBOTest {

	private ClientBO clientBO = new ClientBOImpl();

	@Test
	public void testClientProductSum() throws DifferentCurrenciesException {

		List<Product> products = new ArrayList<Product>();

		products.add(new ProductImpl(100, "Product 15",
				ProductType.BANK_GUARANTEE, new AmountImpl(
						new BigDecimal("5.0"), Currency.EURO)));

		products.add(new ProductImpl(120, "Product 20",
				ProductType.BANK_GUARANTEE, new AmountImpl(
						new BigDecimal("6.0"), Currency.EURO)));

		Amount temp = clientBO.getClientProductsSum(products);

		assertEquals(Currency.EURO, temp.getCurrency());
		assertEquals(new BigDecimal("11.0"), temp.getValue());
	}

	@Test(expected = DifferentCurrenciesException.class)
	public void testClientProductSum1() throws DifferentCurrenciesException {

		List<Product> products = new ArrayList<Product>();

		products.add(new ProductImpl(100, "Product 15",
				ProductType.BANK_GUARANTEE, new AmountImpl(
						new BigDecimal("5.0"), Currency.INDIAN_RUPEE)));

		products.add(new ProductImpl(120, "Product 20",
				ProductType.BANK_GUARANTEE, new AmountImpl(
						new BigDecimal("6.0"), Currency.EURO)));

		@SuppressWarnings("unused")
		Amount temp = null;

		temp = clientBO.getClientProductsSum(products);
	}

	@Test
	public void testClientProductSum2() {

		List<Product> products = new ArrayList<Product>();

		Amount temp = null;

		try {
			temp = clientBO.getClientProductsSum(products);
		} catch (DifferentCurrenciesException e) {
		}
		assertEquals(Currency.EURO, temp.getCurrency());
		assertEquals(BigDecimal.ZERO, temp.getValue());
	}

}

/src/test/java/com/clarity/business/ClientBOTestRefactored.java

package com.clarity.business;

import static org.junit.Assert.assertEquals;

import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.List;

import org.junit.Test;

import com.in28minutes.junit.business.ClientBO;
import com.in28minutes.junit.business.ClientBOImpl;
import com.in28minutes.junit.business.exception.DifferentCurrenciesException;
import com.in28minutes.junit.model.Amount;
import com.in28minutes.junit.model.AmountImpl;
import com.in28minutes.junit.model.Currency;
import com.in28minutes.junit.model.Product;
import com.in28minutes.junit.model.ProductImpl;
import com.in28minutes.junit.model.ProductType;

public class ClientBOTestRefactored {

	private ClientBO clientBO = new ClientBOImpl();

	@Test
	public void testClientProductSum_AllProductsSameCurrency()
			throws DifferentCurrenciesException {

		Amount[] amounts = {
				new AmountImpl(new BigDecimal("5.0"), Currency.EURO),
				new AmountImpl(new BigDecimal("6.0"), Currency.EURO) };

		Amount expected = new AmountImpl(new BigDecimal("11.0"), Currency.EURO);
		
		List<Product> products = createProductListWithAmounts(amounts);

		Amount actual = clientBO.getClientProductsSum(products);

		assertAmount(actual, expected);
	}

	@Test(expected = DifferentCurrenciesException.class)
	public void testClientProductSum_DifferentCurrencies_ThrowsException()
			throws DifferentCurrenciesException {

		Amount[] amounts = {
				new AmountImpl(new BigDecimal("5.0"), Currency.EURO),
				new AmountImpl(new BigDecimal("6.0"), Currency.INDIAN_RUPEE) };

		List<Product> products = createProductListWithAmounts(amounts);

		@SuppressWarnings("unused")
		Amount actual = clientBO.getClientProductsSum(products);

	}

	@Test
	public void testClientProductSum_NoProducts()
			throws DifferentCurrenciesException {

		Amount[] amounts = {};
		Amount expected = new AmountImpl(BigDecimal.ZERO, Currency.EURO);

		List<Product> products = createProductListWithAmounts(amounts);

		Amount actual = clientBO.getClientProductsSum(products);


		assertAmount(actual, expected);
	}

	private void assertAmount(Amount actual, Amount expected) {
		assertEquals(expected.getCurrency(), actual.getCurrency());
		assertEquals(expected.getValue(), actual.getValue());
	}

	private List<Product> createProductListWithAmounts(Amount[] amounts) {
		List<Product> products = new ArrayList<Product>();
		for (Amount amount : amounts) {
			products.add(new ProductImpl(100, "Product 15",
					ProductType.BANK_GUARANTEE, amount));
		}
		return products;
	}

}

/src/test/java/com/in28minutes/business/TodoBusinessImplMockitoInjectMocksTest.java

package com.in28minutes.business;

import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertThat;
import static org.mockito.BDDMockito.given;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

import java.util.Arrays;
import java.util.List;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.ArgumentCaptor;
import org.mockito.Captor;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.mockito.runners.MockitoJUnitRunner;

import com.in28minutes.data.api.TodoService;

@RunWith(MockitoJUnitRunner.class)
public class TodoBusinessImplMockitoInjectMocksTest {
	@Mock
	TodoService todoService;

	@InjectMocks
	TodoBusinessImpl todoBusinessImpl;

	@Captor
	ArgumentCaptor<String> stringArgumentCaptor;

	@Test
	public void usingMockito() {
		List<String> allTodos = Arrays.asList("Learn Spring MVC",
				"Learn Spring", "Learn to Dance");

		when(todoService.retrieveTodos("Ranga")).thenReturn(allTodos);

		List<String> todos = todoBusinessImpl
				.retrieveTodosRelatedToSpring("Ranga");
		assertEquals(2, todos.size());
	}

	@Test
	public void usingMockito_UsingBDD() {
		List<String> allTodos = Arrays.asList("Learn Spring MVC",
				"Learn Spring", "Learn to Dance");

		//given
		given(todoService.retrieveTodos("Ranga")).willReturn(allTodos);

		//when
		List<String> todos = todoBusinessImpl
				.retrieveTodosRelatedToSpring("Ranga");

		//then
		assertThat(todos.size(), is(2));
	}

	@Test
	public void letsTestDeleteNow() {

		List<String> allTodos = Arrays.asList("Learn Spring MVC",
				"Learn Spring", "Learn to Dance");

		when(todoService.retrieveTodos("Ranga")).thenReturn(allTodos);

		todoBusinessImpl.deleteTodosNotRelatedToSpring("Ranga");

		verify(todoService).deleteTodo("Learn to Dance");

		verify(todoService, Mockito.never()).deleteTodo("Learn Spring MVC");

		verify(todoService, Mockito.never()).deleteTodo("Learn Spring");

		verify(todoService, Mockito.times(1)).deleteTodo("Learn to Dance");
		// atLeastOnce, atLeast

	}

	@Test
	public void captureArgument() {
		List<String> allTodos = Arrays.asList("Learn Spring MVC",
				"Learn Spring", "Learn to Dance");
		Mockito.when(todoService.retrieveTodos("Ranga")).thenReturn(allTodos);

		todoBusinessImpl.deleteTodosNotRelatedToSpring("Ranga");
		Mockito.verify(todoService).deleteTodo(stringArgumentCaptor.capture());

		assertEquals("Learn to Dance", stringArgumentCaptor.getValue());
	}
}

/src/test/java/com/in28minutes/business/TodoBusinessImplMockitoRulesTest.java

package com.in28minutes.business;

import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertThat;
import static org.mockito.BDDMockito.given;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

import java.util.Arrays;
import java.util.List;

import org.junit.Rule;
import org.junit.Test;
import org.mockito.ArgumentCaptor;
import org.mockito.Captor;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.mockito.junit.MockitoJUnit;
import org.mockito.junit.MockitoRule;

import com.in28minutes.data.api.TodoService;

public class TodoBusinessImplMockitoRulesTest {

	@Rule
	public MockitoRule mockitoRule = MockitoJUnit.rule();

	@Mock
	TodoService todoService;

	@InjectMocks
	TodoBusinessImpl todoBusinessImpl;

	@Captor
	ArgumentCaptor<String> stringArgumentCaptor;

	@Test
	public void usingMockito() {
		List<String> allTodos = Arrays.asList("Learn Spring MVC",
				"Learn Spring", "Learn to Dance");

		when(todoService.retrieveTodos("Ranga")).thenReturn(allTodos);

		List<String> todos = todoBusinessImpl
				.retrieveTodosRelatedToSpring("Ranga");
		assertEquals(2, todos.size());
	}

	@Test
	public void usingMockito_UsingBDD() {
		List<String> allTodos = Arrays.asList("Learn Spring MVC",
				"Learn Spring", "Learn to Dance");

		//given
		given(todoService.retrieveTodos("Ranga")).willReturn(allTodos);

		//when
		List<String> todos = todoBusinessImpl
				.retrieveTodosRelatedToSpring("Ranga");

		//then
		assertThat(todos.size(), is(2));
	}

	@Test
	public void letsTestDeleteNow() {

		List<String> allTodos = Arrays.asList("Learn Spring MVC",
				"Learn Spring", "Learn to Dance");

		when(todoService.retrieveTodos("Ranga")).thenReturn(allTodos);

		todoBusinessImpl.deleteTodosNotRelatedToSpring("Ranga");

		verify(todoService).deleteTodo("Learn to Dance");

		verify(todoService, Mockito.never()).deleteTodo("Learn Spring MVC");

		verify(todoService, Mockito.never()).deleteTodo("Learn Spring");

		verify(todoService, Mockito.times(1)).deleteTodo("Learn to Dance");
		// atLeastOnce, atLeast

	}

	@Test
	public void captureArgument() {
		List<String> allTodos = Arrays.asList("Learn Spring MVC",
				"Learn Spring", "Learn to Dance");
		Mockito.when(todoService.retrieveTodos("Ranga")).thenReturn(allTodos);

		todoBusinessImpl.deleteTodosNotRelatedToSpring("Ranga");
		Mockito.verify(todoService).deleteTodo(stringArgumentCaptor.capture());

		assertEquals("Learn to Dance", stringArgumentCaptor.getValue());
	}
}

/src/test/java/com/in28minutes/business/TodoBusinessImplMockitoTest.java

package com.in28minutes.business;

import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertThat;
import static org.mockito.BDDMockito.given;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

import java.util.Arrays;
import java.util.List;

import org.junit.Test;
import org.mockito.ArgumentCaptor;
import org.mockito.Mockito;

import com.in28minutes.data.api.TodoService;

public class TodoBusinessImplMockitoTest {

	@Test
	public void usingMockito() {
		TodoService todoService = mock(TodoService.class);
		List<String> allTodos = Arrays.asList("Learn Spring MVC",
				"Learn Spring", "Learn to Dance");
		when(todoService.retrieveTodos("Ranga")).thenReturn(allTodos);
		TodoBusinessImpl todoBusinessImpl = new TodoBusinessImpl(todoService);
		List<String> todos = todoBusinessImpl
				.retrieveTodosRelatedToSpring("Ranga");
		assertEquals(2, todos.size());
	}

	@Test
	public void usingMockito_UsingBDD() {
		TodoService todoService = mock(TodoService.class);
		TodoBusinessImpl todoBusinessImpl = new TodoBusinessImpl(todoService);
		List<String> allTodos = Arrays.asList("Learn Spring MVC",
				"Learn Spring", "Learn to Dance");

		//given
		given(todoService.retrieveTodos("Ranga")).willReturn(allTodos);

		//when
		List<String> todos = todoBusinessImpl
				.retrieveTodosRelatedToSpring("Ranga");

		//then
		assertThat(todos.size(), is(2));
	}

	@Test
	public void letsTestDeleteNow() {

		TodoService todoService = mock(TodoService.class);

		List<String> allTodos = Arrays.asList("Learn Spring MVC",
				"Learn Spring", "Learn to Dance");

		when(todoService.retrieveTodos("Ranga")).thenReturn(allTodos);

		TodoBusinessImpl todoBusinessImpl = new TodoBusinessImpl(todoService);

		todoBusinessImpl.deleteTodosNotRelatedToSpring("Ranga");

		verify(todoService).deleteTodo("Learn to Dance");

		verify(todoService, Mockito.never()).deleteTodo("Learn Spring MVC");

		verify(todoService, Mockito.never()).deleteTodo("Learn Spring");

		verify(todoService, Mockito.times(1)).deleteTodo("Learn to Dance");
		// atLeastOnce, atLeast

	}

	@Test
	public void captureArgument() {
		ArgumentCaptor<String> argumentCaptor = ArgumentCaptor
				.forClass(String.class);

		TodoService todoService = mock(TodoService.class);

		List<String> allTodos = Arrays.asList("Learn Spring MVC",
				"Learn Spring", "Learn to Dance");
		Mockito.when(todoService.retrieveTodos("Ranga")).thenReturn(allTodos);

		TodoBusinessImpl todoBusinessImpl = new TodoBusinessImpl(todoService);
		todoBusinessImpl.deleteTodosNotRelatedToSpring("Ranga");
		Mockito.verify(todoService).deleteTodo(argumentCaptor.capture());

		assertEquals("Learn to Dance", argumentCaptor.getValue());
	}
}

/src/test/java/com/in28minutes/business/TodoBusinessImplStubTest.java

package com.in28minutes.business;

import static org.junit.Assert.assertEquals;

import java.util.List;

import org.junit.Test;

import com.in28minutes.data.api.TodoService;
import com.in28minutes.data.stub.TodoServiceStub;

public class TodoBusinessImplStubTest {

	@Test
	public void usingAStub() {
		TodoService todoService = new TodoServiceStub();
		TodoBusinessImpl todoBusinessImpl = new TodoBusinessImpl(todoService);
		List<String> todos = todoBusinessImpl
				.retrieveTodosRelatedToSpring("Ranga");
		assertEquals(2, todos.size());
	}
}

/src/test/java/com/in28minutes/data/stub/TodoServiceStub.java

package com.in28minutes.data.stub;

import java.util.Arrays;
import java.util.List;

import com.in28minutes.data.api.TodoService;

public class TodoServiceStub implements TodoService {
	public List<String> retrieveTodos(String user) {
		return Arrays.asList("Learn Spring MVC", "Learn Spring",
				"Learn to Dance");
	}

	public void deleteTodo(String todo) {

	}
}

/src/test/java/com/in28minutes/junit/helper/ArraysCompareTest.java

package com.in28minutes.junit.helper;

import static org.junit.Assert.*;

import java.util.Arrays;

import org.junit.Test;

public class ArraysCompareTest {

	@Test
	public void testArraySort_RandomArray() {
		int[] numbers = { 12, 3, 4, 1 };
		int[] expected = { 1, 3, 4, 12 };
		Arrays.sort(numbers);
		assertArrayEquals(expected, numbers);
	}

	@Test(expected=NullPointerException.class)
	public void testArraySort_NullArray() {
		int[] numbers = null;
		Arrays.sort(numbers);
	}
	
	@Test(timeout=100)
	public void testSort_Performance(){
		int array[] = {12,23,4};
		for(int i=1;i<=1000000;i++)
		{
			array[0] = i;
			Arrays.sort(array);
		}
	}

}

/src/test/java/com/in28minutes/junit/helper/ArraysTest.java

package com.in28minutes.junit.helper;

import static org.junit.Assert.*;


import java.util.Arrays;

import org.junit.Test;

public class ArraysTest {
	@Test(timeout=100)
	public void testPerformance() {
		for(int  i=0;i<1000000;i++){
			Arrays.sort(new int[]{i,i-1,i+1});
		}
	}
}

/src/test/java/com/in28minutes/junit/helper/QuickBeforeAfterTest.java

package com.in28minutes.junit.helper;

import static org.junit.Assert.*;

import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;

public class QuickBeforeAfterTest {
	
	@BeforeClass
	public static void beforeClass(){
		System.out.println("Before Class");
	}
	
	@Before
	public void setup(){
		System.out.println("Before Test");
	}

	@Test
	public void test1() {
		System.out.println("test1 executed");
	}

	@Test
	public void test2() {
		System.out.println("test2 executed");
	}
	
	@After
	public void teardown() {
		System.out.println("After test");
	}
	
	@AfterClass
	public static void afterClass(){
		System.out.println("After Class");
	}

}

/src/test/java/com/in28minutes/junit/helper/StringHelperParameterizedTest.java

package com.in28minutes.junit.helper;

import static org.junit.Assert.*;

import java.util.Arrays;
import java.util.Collection;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;

@RunWith(Parameterized.class)
public class StringHelperParameterizedTest {

	// AACD => CD ACD => CD CDEF=>CDEF CDAA => CDAA

	StringHelper helper = new StringHelper();
	
	private String input;
	private String expectedOutput;
	
	public StringHelperParameterizedTest(String input, String expectedOutput) {
		this.input = input;
		this.expectedOutput = expectedOutput;
	}

	@Parameters
	public static Collection<String[]> testConditions() {
		String expectedOutputs[][] = { 
				{ "AACD", "CD" }, 
				{ "ACD", "CD" } };
		return Arrays.asList(expectedOutputs);
	}

	@Test
	public void testTruncateAInFirst2Positions() {
		assertEquals(expectedOutput, 
				helper.truncateAInFirst2Positions(input));
	}
}

/src/test/java/com/in28minutes/junit/helper/StringHelperTest.java

package com.in28minutes.junit.helper;

import static org.junit.Assert.*;

import org.junit.Before;
import org.junit.Test;

public class StringHelperTest {

	// AACD => CD ACD => CD CDEF=>CDEF CDAA => CDAA

	StringHelper helper;
	
	@Before
	public void before(){
		helper = new StringHelper();
	}
	

	@Test
	public void testTruncateAInFirst2Positions_AinFirst2Positions() {
		assertEquals("CD", helper.truncateAInFirst2Positions("AACD"));
	}

	@Test
	public void testTruncateAInFirst2Positions_AinFirstPosition() {
		assertEquals("CD", helper.truncateAInFirst2Positions("ACD"));
	}

	// ABCD => false, ABAB => true, AB => true, A => false
	@Test
	public void testAreFirstAndLastTwoCharactersTheSame_BasicNegativeScenario() {
		assertFalse( 
				helper.areFirstAndLastTwoCharactersTheSame("ABCD"));
	}

	@Test
	public void testAreFirstAndLastTwoCharactersTheSame_BasicPositiveScenario() {
		assertTrue( 
				helper.areFirstAndLastTwoCharactersTheSame("ABAB"));
	}

	
}

/src/test/java/com/in28minutes/junit/suite/DummyTestSuite.java

package com.in28minutes.junit.suite;

import org.junit.runner.RunWith;
import org.junit.runners.Suite;
import org.junit.runners.Suite.SuiteClasses;

import com.in28minutes.junit.helper.ArraysTest;
import com.in28minutes.junit.helper.StringHelperTest;

@RunWith(Suite.class)
@SuiteClasses({ArraysTest.class,StringHelperTest.class})
public class DummyTestSuite {

}

/src/test/java/com/in28minutes/mockito/FirstMockitoTest.java

package com.in28minutes.mockito;

import static org.junit.Assert.assertTrue;

import org.junit.Test;

public class FirstMockitoTest {

	@Test
	public void test() {
		assertTrue(true);
	}

}

/src/test/java/com/in28minutes/mockito/HamcrestMatcherTest.java

package com.in28minutes.mockito;

import static org.hamcrest.CoreMatchers.hasItems;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.arrayContainingInAnyOrder;
import static org.hamcrest.Matchers.arrayWithSize;
import static org.hamcrest.Matchers.greaterThan;
import static org.hamcrest.Matchers.hasSize;
import static org.hamcrest.Matchers.isEmptyOrNullString;
import static org.hamcrest.Matchers.isEmptyString;
import static org.hamcrest.Matchers.lessThan;
import static org.hamcrest.core.Every.everyItem;

import java.util.Arrays;
import java.util.List;

import org.junit.Test;

public class HamcrestMatcherTest {

	@Test
	public void basicHamcrestMatchers() {
		List<Integer> scores = Arrays.asList(99, 100, 101, 105);
		assertThat(scores, hasSize(4));
		assertThat(scores, hasItems(100, 101));
		assertThat(scores, everyItem(greaterThan(90)));
		assertThat(scores, everyItem(lessThan(200)));

		// String
		assertThat("", isEmptyString());
		assertThat(null, isEmptyOrNullString());

		// Array
		Integer[] marks = { 1, 2, 3 };

		assertThat(marks, arrayWithSize(3));
		assertThat(marks, arrayContainingInAnyOrder(2, 3, 1));

	}
}

/src/test/java/com/in28minutes/mockito/ListTest.java

package com.in28minutes.mockito;

import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertThat;
import static org.mockito.BDDMockito.given;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

import java.util.List;

import org.junit.Test;
import org.mockito.Mockito;

public class ListTest {

	@Test
	public void letsMockListSize() {
		List list = mock(List.class);
		when(list.size()).thenReturn(10);
		assertEquals(10, list.size());
	}

	@Test
	public void letsMockListSizeWithMultipleReturnValues() {
		List list = mock(List.class);
		when(list.size()).thenReturn(10).thenReturn(20);
		assertEquals(10, list.size()); // First Call
		assertEquals(20, list.size()); // Second Call
	}

	@Test
	public void letsMockListGet() {
		List<String> list = mock(List.class);
		when(list.get(0)).thenReturn("in28Minutes");
		assertEquals("in28Minutes", list.get(0));
		assertNull(list.get(1));
	}

	@Test(expected = RuntimeException.class)
	public void letsMockListGetToThrowException() {
		List<String> list = mock(List.class);
		when(list.get(Mockito.anyInt())).thenThrow(
				new RuntimeException("Something went wrong"));
		list.get(0);
	}

	@Test
	public void letsMockListGetWithAny() {
		List<String> list = mock(List.class);
		Mockito.when(list.get(Mockito.anyInt())).thenReturn("in28Minutes");
		// If you are using argument matchers, all arguments
		// have to be provided by matchers.
		assertEquals("in28Minutes", list.get(0));
		assertEquals("in28Minutes", list.get(1));
	}

	@Test
	public void bddAliases_UsingGivenWillReturn() {
		List<String> list = mock(List.class);

		//given
		given(list.get(Mockito.anyInt())).willReturn("in28Minutes");

		//then
		assertThat("in28Minutes", is(list.get(0)));
		assertThat("in28Minutes", is(list.get(0)));
	}
}

/src/test/java/com/in28minutes/mockito/SpyTest.java

package com.in28minutes.mockito;

import static org.junit.Assert.assertEquals;
import static org.mockito.Mockito.spy;
import static org.mockito.Mockito.stub;
import static org.mockito.Mockito.verify;

import java.util.ArrayList;
import java.util.List;

import org.junit.Test;

public class SpyTest {

	@Test
	public void creatingASpyOnArrayList() {
		List<String> listSpy = spy(ArrayList.class);
		listSpy.add("Ranga");
		listSpy.add("in28Minutes");

		verify(listSpy).add("Ranga");
		verify(listSpy).add("in28Minutes");

		assertEquals(2, listSpy.size());
		assertEquals("Ranga", listSpy.get(0));
	}

	@Test
	public void creatingASpyOnArrayList_overridingSpecificMethods() {
		List<String> listSpy = spy(ArrayList.class);
		listSpy.add("Ranga");
		listSpy.add("in28Minutes");

		stub(listSpy.size()).toReturn(-1);

		assertEquals(-1, listSpy.size());
		assertEquals("Ranga", listSpy.get(0));

		// @Spy Annotation
	}

}

/src/test/java/com/in28minutes/powermock/PowerMockitoMockingStaticMethodTest.java

package com.in28minutes.powermock;

import static org.junit.Assert.assertEquals;
import static org.mockito.Matchers.anyLong;
import static org.mockito.Mockito.when;

import java.util.Arrays;

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

@RunWith(PowerMockRunner.class)
@PrepareForTest({ UtilityClass.class})
public class PowerMockitoMockingStaticMethodTest {

	@Mock
	Dependency dependencyMock;

	@InjectMocks
	SystemUnderTest systemUnderTest;

	@Test
	public void powerMockito_MockingAStaticMethodCall() {

		when(dependencyMock.retrieveAllStats()).thenReturn(
				Arrays.asList(1, 2, 3));

		PowerMockito.mockStatic(UtilityClass.class);

		when(UtilityClass.staticMethod(anyLong())).thenReturn(150);

		assertEquals(150, systemUnderTest.methodCallingAStaticMethod());

		//To verify a specific method call
		//First : Call PowerMockito.verifyStatic() 
		//Second : Call the method to be verified
		PowerMockito.verifyStatic();
		UtilityClass.staticMethod(1 + 2 + 3);

		// verify exact number of calls
		//PowerMockito.verifyStatic(Mockito.times(1));

	}
}

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Step15.md

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What You Will Learn during this Step:

Useful Snippets and References

Files List

Files List

/pom.xml

/src/main/java/com/in28minutes/business/TodoBusinessImpl.java

/src/main/java/com/in28minutes/data/api/TodoService.java

/src/main/java/com/in28minutes/junit/business/ClientBO.java

/src/main/java/com/in28minutes/junit/business/ClientBOImpl.java

/src/main/java/com/in28minutes/junit/business/exception/DifferentCurrenciesException.java

/src/main/java/com/in28minutes/junit/helper/StringHelper.java

/src/main/java/com/in28minutes/junit/model/Amount.java

/src/main/java/com/in28minutes/junit/model/AmountImpl.java

/src/main/java/com/in28minutes/junit/model/Client.java

/src/main/java/com/in28minutes/junit/model/ClientImpl.java

/src/main/java/com/in28minutes/junit/model/ClientType.java

/src/main/java/com/in28minutes/junit/model/Collateral.java

/src/main/java/com/in28minutes/junit/model/CollateralImpl.java

/src/main/java/com/in28minutes/junit/model/CollateralType.java

/src/main/java/com/in28minutes/junit/model/Currency.java

/src/main/java/com/in28minutes/junit/model/Product.java

/src/main/java/com/in28minutes/junit/model/ProductImpl.java

/src/main/java/com/in28minutes/junit/model/ProductType.java

/src/main/java/com/in28minutes/powermock/SystemUnderTest.java

/src/main/java/com/in28minutes/powermock/UtilityClass.java

/src/test/java/com/clarity/business/ClientBOTest.java

/src/test/java/com/clarity/business/ClientBOTestRefactored.java

/src/test/java/com/in28minutes/business/TodoBusinessImplMockitoInjectMocksTest.java

/src/test/java/com/in28minutes/business/TodoBusinessImplMockitoRulesTest.java

/src/test/java/com/in28minutes/business/TodoBusinessImplMockitoTest.java

/src/test/java/com/in28minutes/business/TodoBusinessImplStubTest.java

/src/test/java/com/in28minutes/data/stub/TodoServiceStub.java

/src/test/java/com/in28minutes/junit/helper/ArraysCompareTest.java

/src/test/java/com/in28minutes/junit/helper/ArraysTest.java

/src/test/java/com/in28minutes/junit/helper/QuickBeforeAfterTest.java

/src/test/java/com/in28minutes/junit/helper/StringHelperParameterizedTest.java

/src/test/java/com/in28minutes/junit/helper/StringHelperTest.java

/src/test/java/com/in28minutes/junit/suite/DummyTestSuite.java

/src/test/java/com/in28minutes/mockito/FirstMockitoTest.java

/src/test/java/com/in28minutes/mockito/HamcrestMatcherTest.java

/src/test/java/com/in28minutes/mockito/ListTest.java

/src/test/java/com/in28minutes/mockito/SpyTest.java

/src/test/java/com/in28minutes/powermock/PowerMockitoMockingStaticMethodTest.java