attach something if assertion failed

[NewbieProger]

Hello.

I have assertion:

Assertions.assertThat(messageCount)
				.withFailMessage("Expected number of messages %s, got %s",
						expectedMessageQty, messageCount)
				.isEqualTo(expectedMessageQty);

I need to attach smth if assertiong falied. something like this:

Assertions.assertThat(messageCount)
				.withFailMessage("Expected number of messages %s, got %s",
						expectedMessageQty, messageCount)
                                /*Here I  want to see some method, where I can do something if assertion failed, like in stream with peek(), for ex*/ 
                                .methodLikePeekIfAssertionFailed(Allure.attachment("Lala", attachment))
				.isEqualTo(expectedMessageQty);

[scordio]

Hard assertions do not really have a callback mechanism, but soft assertions might serve your purpose.

There are two options:

• Call setAfterAssertionErrorCollected on a custom SoftAssertions instance, providing your own AfterAssertionErrorCollected implementation (can be a lambda).
• Extend AbstractSoftAssertions and overrride onAssertionErrorCollected​.

Both ways allow you to provide your own logic to be executed with each assertion error.

Examples of both solutions are in the AssertJ documentation.