test/langtools/tools/javac/lambda/T8175317.java

/*
 * @test /nodynamiccopyright/
 * @bug 8175317
 * @summary javac does not issue unchecked warnings when checking method reference return types
 * @compile/fail/ref=T8175317.out -Werror -Xlint:unchecked -XDrawDiagnostics T8175317.java
 */

import java.util.function.*;
import java.util.*;

class T8175317 {
    void m(Supplier<List<String>> s) { }

    void testMethodLambda(List l) {
        m(() -> l);
    }

    void testAssignLambda(List l) {
        Supplier<List<String>> s = () -> l;
    }

    void testMethodMref() {
        m(this::g);
    }

    void testAssignMref() {
        Supplier<List<String>> s = this::g;
    }

    List g() { return null; }
}