org.junit.contrib.java.lang.system

Class ExpectedSystemExit

java.lang.Object

org.junit.contrib.java.lang.system.ExpectedSystemExit

All Implemented Interfaces:

org.junit.rules.TestRule

public class ExpectedSystemExit
extends java.lang.Object
implements org.junit.rules.TestRule

The ExpectedSystemExit allows in-test specification of expected System.exit(...) calls.

If your code calls System.exit(), then your test stops and doesn't finish. The ExpectedSystemExit rule allows in-test specification of expected System.exit() calls. Furthermore you cannot use JUnit's assert methods because of the abnormal termination of your code. As a substitute you can provide an Assertion object to the ExpectedSystemExit rule.

Some care must be taken if your system under test creates a new thread and this thread calls System.exit(). In this case you have to ensure that the test does not finish before System.exit() is called.

 public class AppWithExit {
        public static String message;

        public static int doSomethingAndExit() {
                message = "exit ...";
                System.exit(1);
        }

        public static int doNothing() {
        }
 }
 

 public void AppWithExitTest {
   @Rule
   public final ExpectedSystemExit exit = ExpectedSystemExit.none();

   @Test
   public void exits() {
     exit.expectSystemExit();
     AppWithExit.doSomethingAndExit();
   }

   @Test
   public void exitsWithStatusCode1() {
     exit.expectSystemExitWithStatus(1);
     AppWithExit.doSomethingAndExit();
   }

   @Test
   public void writesMessage() {
     exit.checkAssertionAfterwards(new Assertion() {
       public void checkAssertion() {
         assertEquals("exit ...", AppWithExit.message);
       }
     });
     AppWithExit.doSomethingAndExit();
   }

   @Test
   public void systemExitWithStatusCode1() {
     exit.expectSystemExitWithStatus(1);
     AppWithExit.doSomethingAndExit();
   }

   @Test
   public void noSystemExit() {
     AppWithExit.doNothing();
     //passes
   }
 }
 

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.Collection<Assertion>	assertions
private java.lang.Integer	expectedStatus
private boolean	expectExit

Constructor Summary

Constructors

Modifier	Constructor and Description
private	ExpectedSystemExit()

Method Summary

Modifier and Type	Method and Description
org.junit.runners.model.Statement	apply(org.junit.runners.model.Statement base, org.junit.runner.Description description)
void	checkAssertionAfterwards(Assertion assertion)
private void	checkAssertions()
private void	checkSystemExit()
private ProvideSecurityManager	createNoExitSecurityManagerRule()
private org.junit.runners.model.Statement	createStatement(org.junit.runners.model.Statement base)
void	expectSystemExit()
void	expectSystemExitWithStatus(int status)
private void	handleMissingSystemExit()
private void	handleSystemExitWithStatus(int status)
static ExpectedSystemExit	none()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

assertions

private final java.util.Collection<Assertion> assertions

expectExit

private boolean expectExit

expectedStatus

private java.lang.Integer expectedStatus

Constructor Detail

ExpectedSystemExit

private ExpectedSystemExit()

Method Detail

none

public static ExpectedSystemExit none()

expectSystemExitWithStatus

public void expectSystemExitWithStatus(int status)

expectSystemExit

public void expectSystemExit()

checkAssertionAfterwards

public void checkAssertionAfterwards(Assertion assertion)

apply

public org.junit.runners.model.Statement apply(org.junit.runners.model.Statement base,
                                               org.junit.runner.Description description)

Specified by:

apply in interface org.junit.rules.TestRule

createNoExitSecurityManagerRule

private ProvideSecurityManager createNoExitSecurityManagerRule()

createStatement

private org.junit.runners.model.Statement createStatement(org.junit.runners.model.Statement base)

checkSystemExit

private void checkSystemExit()

handleMissingSystemExit

private void handleMissingSystemExit()

handleSystemExitWithStatus

private void handleSystemExitWithStatus(int status)

checkAssertions

private void checkAssertions()
                      throws java.lang.Exception

Throws:

java.lang.Exception