How can I test if a particular exception is not thrown?

Question

Can I test whether a particular Exception is not thrown?

The other way round is easy using @Test[expect=MyException].

But how can I negate this?

This will test, that the exception is thrown. It will fail if the exception is not thrown. So it already does what you want (?) — oers, Dec 20 '11 at 12:52
Your title (both before and after editing) contradict your question's text. What specifically are you trying to do? — Dave Newton, Dec 20 '11 at 12:56
Sorry, i ment how can i test if a particular Exception is not thrown — Acdc RocknRoll, Dec 20 '11 at 14:30
possible duplicate of [How to test that no exception is thrown?](http://stackoverflow.com/questions/17731234/how-to-test-that-no-exception-is-thrown) — Jeroen Vannevel, Mar 05 '15 at 15:55

score 22 · Accepted Answer · answered Dec 20 '11 at 14:46

If you want to test if a particular Exception is not thrown in a condition where other exceptions could be thrown, try this:

try {
  myMethod();
}
catch (ExceptionNotToThrow entt){
  fail("WHOOPS! Threw ExceptionNotToThrow" + entt.toString);
}
catch (Throwable t){
  //do nothing since other exceptions are OK
}
assertTrue(somethingElse);
//done!

score 6 · Answer 2 · answered Jul 27 '17 at 12:23

You can do the following using assertj

if you want to check if exception is not thrown then

Throwable throwable = catchThrowable(() -> sut.method());

assertThat(throwable).isNull();

or you expect to throw

Throwable throwable = catchThrowable(() -> sut.method());

assertThat(throwable).isInstanceOf(ClassOfExecption.class)
                     .hasMessageContaining("expected message");

score 3 · Answer 3 · answered Jun 22 '12 at 15:37

3

catch-exception makes the example of Freiheit a bit more concise:

catchException(a).myMethod();
assertFalse(caughtException() instanceof ExceptionNotToThrow);

answered Jun 22 '12 at 15:37

rwitzel

1,694
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score 1 · Answer 4 · answered Apr 26 '22 at 21:23

1

Another latest solution could be using Junit5 assertDoesNotThrow:

assertDoesNotThrow( () -> myMethod() , "MyException is not thrown")

answered Apr 26 '22 at 21:23

Sasi Kathimanda

1,788
3
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score 0 · Answer 5 · answered Jun 04 '22 at 12:34

0

Use @Test(expected = Test.None::class) (in Kotlin)

answered Jun 04 '22 at 12:34

jhavatar

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11

How can I test if a particular exception is not thrown?

5 Answers5

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