Assertj-core: Java6Assertions is calling a Java 8 Streams method

[tir38]

We hit this stack trace on our Android test:

java.lang.NoSuchMethodError: No interface method stream()Ljava/util/stream/Stream; in class Ljava/util/Collection; or its super classes (declaration of 'java.util.Collection' appears in /system/framework/core-libart.jar)
at org.assertj.core.util.Streams.stream(Streams.java:32)
at org.assertj.core.util.Lists.newArrayList(Lists.java:63)
at org.assertj.core.internal.Iterables.assertContainsExactlyInAnyOrder(Iterables.java:1164)
at org.assertj.core.api.AbstractIterableAssert.containsExactlyInAnyOrder(AbstractIterableAssert.java:285)
at org.assertj.core.api.ListAssert.containsExactlyInAnyOrder(ListAssert.java:277)
at org.assertj.core.api.ListAssert.containsExactlyInAnyOrder(ListAssert.java:49)
at com.example.SomeTest_someTestMethod(SomeTest.java:79)

You can see that Streams got added to Android in API 24, so our tests are crashing on earlier versions.

https://developer.android.com/reference/java/util/stream/Stream

We are using the correct Java6 import in our test:

import static org.assertj.core.api.Java6Assertions.assertThat;

@Test
public void someTestMethod() {
    ...
    assertThat(actualIds).containsExactlyInAnyOrder(ID_1, ID_2);
}

I don't fully understand how the Java6Assertions package accomplishes it's task, but one of the subsequent calls is not calling purely Java-6 code.

[joel-costigliola]

Sorry about that, it is likely due to an internal refactoring. which version are you using ?

[epeee]

It looks like this one occurs starting from 3.11.0.

[joel-costigliola]

It's a bit difficult to be aware of android incompatibility since we don't have tests for that.
We have a bunch of assertions that relies on java 8 API (anySatisfy for example), I don't see an easy way to provide Android assertions access only. @PascalSchumacher @benblank thoughts ?

@tir38 the best option is to use assertj-core 2.9.1 which is built with java 7 thus ensuring no java 8 api is used.

[tir38]

Please forgive my ignorance but why are these assertions accessible via the Java6Assertions class in the first place? Given that ListAssert uses Java8 features, why does Java6Assertions even have an assertThat method that returns a ListAssert? https://github.com/joel-costigliola/assertj-core/blob/master/src/main/java/org/assertj/core/api/Java6Assertions.java#L545

[joel-costigliola]

I was our attempt at the pre java 8 time to expose assertions for java 6 types only (which List is part of).

Obviously we failed to maintain the java 6 compatibility when adding new assertions for List or simply refactoring the internal implementation. Sorry for that.

Since we are not going to remove java 8 specific assertions from the current version, the only safe way to use AssertJ for Android is to use assertj-core 2.9.1.

We will update the documentation to reflect that.

[PascalSchumacher]

As newer version of Android support Strams and some Android focused libs are moving to Java 8 it is not worth the bother imho.

As Joel said using 2.x is the best way to ensure no Java 8 features are used.

We should think about deprecating the Java6 assertion classes. In retrospect we should have done it when we stopped developing 2.x and started the Java 8 refactorings.

[joel-costigliola]

Deprecating Java6 assertions classes is a good idea (including documenting what to use instead)
I think once this is done, we can close this issue.

[tir38]

As part of the documentation cleanup, will you be recommending a "min" Android version for use with 3.x?

Or do you think that 3.x won't support Android until Android fully supports Java8? I.e. it's up to Android to fully support Java8 and all AssertJ's cares about is supporting Java8

[joel-costigliola]

I don't think we have a 3.x version that supports Android but 2.9.1 is not that old and provides most of the non java 8 assertions in 3.x.

If you find something important missing in 2.9.1, it is always possible to contribute to it and we will release a new version (but otherwise we don't spend time on 2.x).

[joel-costigliola]

Closing this after deprecating Java 6 assertions entry point classes.

[tir38]

_"I don't think we have a 3.x version that supports Android but 2.9.1 is not that old and provides most of the non java 8 assertions in 3.x."_

Yep so I'm asking if you can update the docs https://assertj.github.io/doc/#assertj-core-java-versions to make it clear that people should use version 2.9.x for all versions of Android?

[PascalSchumacher]

I don't think is correct to say everybody Android developer should use 2.9.x. As you said Stream was added with API Level 24. API level 26 added Path etc., so 3.x (besides SoftAssertions and Assumptions which use the non-Android Byte Buddy variant) should be usable on 26+.

[joel-costigliola]

@tir38 I have clarified this in the doc, is that better ? see https://assertj.github.io/doc/#assertj-core-android