[JAVA] Use FacesContext as a Mock with PowerMockito

Introduction

This post is for mocking FacesContext on junit I don't want to create a subclass like FacesContextMock Described as a memorandum how to use PowerMock and do it in the @ Test method

Premise

Use the following libraries and versions

1. java8
2. junit4.12
3. PowerMockito (using 1.7.3)

sample

UserAuth Session management of user information

UserAuth.java

import java.io.Serializable;

import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import javax.faces.context.FacesContext;

/**
 *User credentials
 */
@ManagedBean
@SessionScoped
public class UserAuth implements Serializable {

	/**User ID*/
	private String userId;
	/**Login status*/
	private boolean logined;

	/**
	 *Logout process
	 *
	 * @return login screen URL
	 */
	public String logout() {
		//Discard session information
		FacesContext.getCurrentInstance().getExternalContext().invalidateSession();

		//Transit to login screen by redirect
		return "/login.xhtml?faces-redirect=true";
	}

	// ... Setter and Getter

}

** UserAuth test ** Test the logout process

UserAuth.java

import static org.hamcrest.CoreMatchers.containsString;
import static org.junit.Assert.assertThat;

import javax.faces.context.ExternalContext;
import javax.faces.context.FacesContext;

import org.junit.Before;
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;

/**
 *UserAuth test class
 */
@RunWith(PowerMockRunner.class)
public class UserAuthTest {

	/**User credentials*/
	private UserAuth userAuth;

	/**
	 *Instantiate user credentials class
	 */
	@Before
	public void bofore() {
		userAuth = new UserAuth();
	}

	/**
	 *Test logout process<br>
	 *The URL of the logout destination is the login screen.
	 */
	@Test
	@PrepareForTest(FacesContext.class)
	public void testLogout() {
		//mock
		PowerMockito.mockStatic(FacesContext.class);
		FacesContext context = PowerMockito.mock(FacesContext.class);
		ExternalContext ext = PowerMockito.mock(ExternalContext.class);
		//method setting
		PowerMockito.when(FacesContext.getCurrentInstance()).thenReturn(context);
		PowerMockito.when(context.getExternalContext()).thenReturn(ext);

		//Check the URL of the logout destination.
		assertThat(userAuth.logout(), containsString("login.xhtml"));
	}
}

Commentary

To use PowerMockito @ RunWith (PowerMockRunner.class) in class annotation Add @PrepareForTest (FacesContext.class) to method annotation

• @PrepareForTest (FacesContext.class) may be a class annotation.

FacesContext.getCurrentInstance () is a static method, so mock it with PowerMockito.mockStatic All subsequent instances called will be mocked with mock

• If you want to mock with mock, you can mock with Mockito.mock.

After that, when the test is executed, mock is called and processing is performed.