checker/tests/nullness/Issue1027.java

// Test case for Issue 1027:
// https://github.com/typetools/checker-framework/issues/1027

// Use  -J-XX:MaxJavaStackTraceDepth=1000000 as parameter
// to javac to see a longer stacktrace.

import java.util.Map;
import java.util.Set;
import java.util.function.Function;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import org.checkerframework.checker.nullness.qual.KeyFor;

public class Issue1027 {

  // Stand-alone reproduction

  class Repr<T> {
    void bar(Function<T, String> p) {}
  }

  @SuppressWarnings("nullness")
  Repr<@KeyFor("this") String> foo() {
    return null;
  }

  void zoo(Issue1027 p) {
    p.foo().bar(x -> "");
  }

  // Various longer versions that also used to give SOE

  void foo(Map<String, String> arg) {
    arg.keySet().stream().map(key -> key);
  }

  Stream<String> foo(Set<String> arg) {
    return arg.stream().map(key -> key);
  }

  String foo(Stream<String> stream) {
    return stream.map(key -> key).collect(Collectors.joining());
  }
}