I'm not sure I fully understand the points mentioned by Roger, Daniel and Paul.
Nevertheless I will kindly disagree with all of them, just for the sake of
having a constructive discussion :-)
My understanding is that org.testng.Assert.assertThrows provides a rich message
explaining what has happened. Here is what I have just seen:
No exception:
assertThrows(NullPointerException.class, () -> { });
outputs:
Exception in thread "main" java.lang.AssertionError: Expected
NullPointerException to be thrown, but nothing was thrown
at org.testng.Assert.expectThrows(Assert.java:1018)
at org.testng.Assert.assertThrows(Assert.java:989)
at MessageTest.main(MessageTest.java:10)
Wrong exception:
assertThrows(NullPointerException.class, () -> { throw new
IllegalArgumentException("Hey!");});
outputs:
Exception in thread "main" java.lang.AssertionError: Expected
NullPointerException to be thrown, but IllegalArgumentException was thrown
at org.testng.Assert.expectThrows(Assert.java:1013)
at org.testng.Assert.assertThrows(Assert.java:989)
at MessageTest.main(MessageTest.java:9)
Caused by: java.lang.IllegalArgumentException: Hey!
at MessageTest.lambda$main$0(MessageTest.java:9)
at org.testng.Assert.expectThrows(Assert.java:1005)
... 2 more
I believe that it is as good as it gets in these situations. And might, just
might, be a tiny bit better than the previous more ahem...cryptic... message:
should throw NPE
I would also disagree with Roger that having the wrong exception in the cause of
a thrown one is "a bit awkward". I think it's more straightforward and leaves
the original exception's message intact and provides even more information.
I would however agree with Paul on having a bunch of shortcuts for standard
exceptions like: assertThrowsNPE, assertThrowsIAE, assertThrowsISE, etc.
-Pavel
>> On 2 May 2017, at 02:19, Amy Lu <[email protected]> wrote:
>>
>> Please review this test-only change.
>>
>> Some java/util tests use a function executeAndCatch which essentially
>> asserts that an exception is thrown, while some other tests use assertThrows
>> for doing the same work. For both cases, with jtreg upgraded to testng 6.9.5
>> (CODETOOLS-7901639), test can then leverage TestNG Assert.assertThrows
>>
>> Please review the patch to update executeAndCatch and assertThrows to
>> Assert.assertThrows for java/util testng tests.
>>
>> bug: https://bugs.openjdk.java.net/browse/JDK-8023897
>> webrev: http://cr.openjdk.java.net/~amlu/8023897/webrev.00/
>>
>> Thanks,
>> Amy
>>
>
