How to compare two Streams in Java 8

Question

What would be a good way to compare two Stream instances in Java 8 and find out whether they have the same elements, specifically for purposes of unit testing?<

Answer 1

You can assert the stream's content without creating a Stream<> expected.

AssertJ has fluent and readable solutions for this.

import static org.assertj.core.api.Assertions.assertThat;
import java.util.stream.Stream;
import org.junit.jupiter.api.Test;

class MyTests {
    @Test
    void test() {
        Stream actual = Stream.of(0, 8, 15); // your thingUnderTest

        assertThat(actual).containsExactly(0, 8, 15);
    }
}