checker/tests/nullness/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;

public 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)
    for (Object x : checkNotNull(xs)) {}
  }
}