checker/tests/nullness/java8/lambda/RefinedLocalInLambda.java

// Test case for issue #1248:
// https://github.com/typetools/checker-framework/issues/1248

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

public class RefinedLocalInLambda {

  public static void main(String[] args) {
    printIntegersGreaterThan(10);
  }

  public static void printIntegersGreaterThan(@Nullable Integer limit) {
    // :: error: (unboxing.of.nullable)
    printIntegersWithPredicate(i -> i > limit); // type-checking fails
    if (limit == null) {
      return;
    }
    printIntegersWithPredicate(i -> i > limit); // type-checking succeeds
    @NonNull Integer limit2 = limit;
    printIntegersWithPredicate(i -> i > limit2); // type-checking succeeds
    Integer limit3 = limit;
    printIntegersWithPredicate(i -> i > limit3); // type-checking succeeds
  }

  public static void printIntegersWithPredicate(Predicate<Integer> tester) {
    for (int i = 0; i < 100; i++) {
      if (tester.test(i)) {
        System.out.println(i);
      }
    }
  }
}