Test that either one thing holds or another in AssertJ

Question

I am in the process of converting some tests from Hamcrest to AssertJ. In Hamcrest I use the following snippet:

assertThat(list, either(contains(Tags.SWEETS, Tags.HIGH))
    .or(contains(Tags.SOUPS, Tags.RED)));

That is, the list may be either that or that. How can I express this in AssertJ? The anyOf function (of course, any is something else than either, but that would be a second question) takes a Condition; I have implemented that myself, but it feels as if this should be a common case.

Answer 1

Edited:

Since 3.12.0 AssertJ provides satisfiesAnyOf which succeeds if at least one of the given assertion succeeds,

assertThat(list).satisfiesAnyOf(
    listParam -> assertThat(listParam).contains(Tags.SWEETS, Tags.HIGH),
    listParam -> assertThat(listParam).contains(Tags.SOUPS, Tags.RED)
);

Original answer:

No, this is an area where Hamcrest is better than AssertJ.

To write the following assertion:

Set<String> goodTags = newLinkedHashSet("Fine", "Good");
Set<String> badTags = newLinkedHashSet("Bad!", "Awful");
Set<String> tags = newLinkedHashSet("Fine", "Good", "Ok", "?");

// contains is statically imported from ContainsCondition
// anyOf succeeds if one of the conditions is met (logical 'or') 
assertThat(tags).has(anyOf(contains(goodTags), contains(badTags)));

you need to create this Condition:

import static org.assertj.core.util.Lists.newArrayList;    
import java.util.Collection;    
import org.assertj.core.api.Condition;

public class ContainsCondition extends Condition<Iterable<String>> {
  private Collection<String> collection;
  
  public ContainsCondition(Iterable<String> values) {
    super("contains " + values);
    this.collection = newArrayList(values);
  }
  
  static ContainsCondition contains(Collection<String> set) {
    return new ContainsCondition(set);
  }

  @Override
  public boolean matches(Iterable<String> actual) {
    Collection<String> values = newArrayList(actual);
    for (String string : collection) {
      if (!values.contains(string)) return false;
    }
    return true;
  };
}

It might not be what you if you expect that the presence of your tags in one collection implies they are not in the other one.