Issue355.java

// Test case for Issue 355:
// https://github.com/typetools/checker-framework/issues/355

import java.util.List;
import org.checkerframework.checker.nullness.qual.NonNull;
import org.checkerframework.checker.nullness.qual.Nullable;

class Issue355 {
    static <T extends @Nullable Object> @NonNull T checkNotNull(@Nullable T sample) {
        throw new RuntimeException();
    }

    void m(List<String> xs) {
        for (String x : checkNotNull(xs)) {}
    }
}

class Issue355b {
    static <T> T checkNotNull(T sample) {
        throw new RuntimeException();
    }

    void m(List<String> xs) {
        for (Object x : checkNotNull(xs)) {}
    }
}

class Issue355c {
    static <T> T checkNotNull(@NonNull T sample) {
        throw new RuntimeException();
    }

    void m(List<String> xs) {
        for (Object x : checkNotNull(xs)) {}
    }
}

class Issue355d {
    static <T> @Nullable T checkNotNull(@NonNull T sample) {
        throw new RuntimeException();
    }

    void m(List<String> xs) {
        //:: error: (iterating.over.nullable)
        for (Object x : checkNotNull(xs)) {}
    }
}

class Issue355e {
    static <T> @NonNull T checkNotNull(@NonNull T sample) {
        throw new RuntimeException();
    }

    void m(@Nullable List<String> xs) {
        //:: error: (argument.type.incompatible)
        for (Object x : checkNotNull(xs)) {}
    }
}