ExpectedSystemExit (System Rules 1.19.0 API)

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
   }
 }

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`org.junit.runners.model.Statement`	`apply(org.junit.runners.model.Statement base, org.junit.runner.Description description)`
`void`	`checkAssertionAfterwards(Assertion assertion)`
`void`	`expectSystemExit()`
`void`	`expectSystemExitWithStatus(int status)`
`static ExpectedSystemExit`	`none()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

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

Class ExpectedSystemExit