Matchers.anyOf: inference variable has incompatible bounds with Java >8 · Issue #256 · hamcrest/JavaHamcrest
The following code sample works with OpenJDK 8 but does not compile with OpenJDK 11:
public class SimpleTest {
@Test
public void test() {
List<String> list = new ArrayList<>();
assertThat(list, anyOf(hasItem("a"), hasItem("b")));
}
}
Compiling with Java 11 fails with
[javac] method Assert.<T#1>assertThat(String,T#1,Matcher<? super T#1>) is not applicable
[javac] (cannot infer type-variable(s) T#1
[javac] (actual and formal argument lists differ in length))
[javac] method Assert.<T#2>assertThat(T#2,Matcher<? super T#2>) is not applicable
[javac] (inference variable T#3 has incompatible bounds
[javac] lower bounds: String,Object
[javac] lower bounds: String,Object)
[javac] where T#1,T#2,T#3 are type-variables:
[javac] T#1 extends Object declared in method <T#1>assertThat(String,T#1,Matcher<? super T#1>)
[javac] T#2 extends Object declared in method <T#2>assertThat(T#2,Matcher<? super T#2>)
[javac] T#3 extends Object declared in method <T#3>hasItem(T#3)
If the first argument of the Matchers.anyOf methods would be changed from Matcher to Matcher<? super T> (like in Matchers.allOf), it would work.