assertThatThrownBy.doesNotThrowAnyException() fails when no exception is thrown

[TheBestPessimist]

Summary

Duplicate of #1787 because that is closed:

Example

    fun thisFunctionDoesNothing() {
        println("i did nothing")
    }

    @Test
    fun `this test should not fail, unfortunately it does`() {
        assertThatThrownBy { thisFunctionDoesNothing() }.doesNotThrowAnyException()
    }

And i get the exception:

Expecting code to raise a throwable.
java.lang.AssertionError: 
Expecting code to raise a throwable.

[onacit]

You already have the comment.

I think the failure came from the assertThatThrownBy not from the doesNotThrowAnyException.

In code,

        Assertions.assertThatThrownBy(() -> { // expects this part throw any exception
                    thisFunctionDoesNothing();
                })
                .doesNotThrowAnyException();

You should've done like,

        Assertions.assertThatCode(() -> {
                    thisFunctionDoesNothing();
                })
                .doesNotThrowAnyException();

[TheBestPessimist]

That's true and i used assertThatCode, however my issue is that doesNotThrowAnyException should be removed from assertThatThrownBy in this case. It leads to unexpected results.

I'm sorry for not explaining that in the OP.

[joel-costigliola]

I agree doesNotThrowAnyException should not be available after calling assertThatThrownBy.
doesNotThrowAnyException is meant to use with assertThatCode as pointed out by @onacit, when we added it we did not realize it would be possible to use it after assertThatThrownBy.

Having said that, we think it is natural for assertThatThrownBy to expect an exception to be thrown (that's the point of this method) so we won't change assertThatThrownBy behavior that fails when none was thrown.

[TheBestPessimist]

doesNotThrowAnyException should not be available after calling assertThatThrownBy

as long as this happens, i'm happy!

at least, I don't have to explain this to any new colleague joining my team.

[hezean]

I agree doesNotThrowAnyException should not be available after calling assertThatThrownBy

Seems to be a great feature! If possible, I'd like to do some investigation and try to work on it 😄

[joel-costigliola]

We are already looking at it @hezean but thanks!

[pandoras-toolbox]

What I miss is this feature to be able to ignore certain exceptions:

 Assertions.assertThatCode(() -> {
                    thisFunctionDoesNothing();
                })
                .doesNotThrowAnyException()
                .ignoring(NoSuchElementException.class);

What do you think about this idea?

[joel-costigliola]

@pandoras-toolbox yep why not ? I would probably go with doesNotThrowAnyExceptionExcept(Class... exceptions), ex:

assertThatCode(() -> { thisFunctionDoesNothing(); })
                .doesNotThrowAnyExceptionExcept(NoSuchElementException.class, IOException.class);

could you create a new issue for this?

[pandoras-toolbox]

Great! I created it.