checker/tests/nullness/Issue1406.java

// Test case for Issue 1406
// https://github.com/typetools/checker-framework/issues/1406

import java.util.ArrayList;
import java.util.List;
import org.checkerframework.checker.nullness.qual.EnsuresNonNull;
import org.checkerframework.dataflow.qual.Pure;

@SuppressWarnings({"purity", "contracts.postcondition"}) // Only test parsing
public class Issue1406 {

  public static void main(String[] args) {}

  @Pure
  @EnsuresNonNull("myMethod(#1).get(0)")
  List<String> myMethod(int arg) {
    List<String> result = new ArrayList<>();
    result.add("non-null value");
    return result;
  }

  String client(int arg) {
    return myMethod(arg).get(0);
  }

  @Pure
  @EnsuresNonNull("myMethod2().get(0)")
  List<String> myMethod2() {
    List<String> result = new ArrayList<>();
    result.add("non-null value");
    return result;
  }

  String client2() {
    return myMethod2().get(0);
  }
}