Is there Kotlin equivalent for AssertJ library? [closed]

Question

I am converting some tests from Java to Kotlin. For Java tests I use AssertJ library which is very powerful and has rich set of assertions. My problem is that for Kotlin tests I can not use AssertJ and Kotlin JUnit (org.jetbrains.kotlin:kotlin-test-junit) has very limited set of assertions.

Is there Kotlin equivalent for AssertJ or better way for asserts?

I found Kluent library but I'm still not sure if this is the best library to use.

Answer 1

There is no official equivalent but basic AssertJ is still usable in many cases and looks quite fine:

assertThat(info)
  .containsKey("foo")


assertThatThrownBy { session.restTemplate.postForLocation("foo", {}) }
  .isExactlyInstanceOf(HttpClientErrorException::class.java)

---

If you want dedicated wrappers, this early-stage project is trying to achieve this: https://github.com/wuan/assertj-core-kotlin

Answer 2

You are probably no longer searching for an assertion library but just in case you are not yet happy with your current choice, have a look at https://github.com/robstoll/atrium

It supports inter alia:

• assertion groups
• assertion functions for nullable types
• property assertions
• method assertions
• postulate that a Throwable was thrown

As well as more advanced features such as sophisticated assertion builders, support for i18n and more.

The examples in the README will give you a nice overview: https://github.com/robstoll/atrium/blob/master/README.md#examples