<item index="10" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NullableDecl" />
          <item index="11" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NullableType" />
          <item index="12" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.qual.Nullable" />

# ADR-0008 - Use NullAway for null checking

## Date

2025-08-06

## Context

Our codebase uses `null` extensively to represent an absence of value or optionality of the argument.
We utilize nullness annotations in Java code and somewhat rely on IDE warnings to guide us.
However, the Java code we have is not fully annotated, which causes several consequences:
* IDE warnings can be misleading

   * but we know that our values will never be `null`.
   */

  @Override
  public Object[] toArray() {
    return snapshotElementsToList().toArray();
  }

  @Override
  @SuppressWarnings("nullness") // b/192354773 in our checker affects toArray declarations
  public <T extends @Nullable Object> T[] toArray(T[] array) {
    return snapshotElementsToList().toArray(array);
  }

  /*

       * overrides, so we declare `@Nullable Object[]` as the return type.
       */
      return standardToArray();
    }

    @Override
    @SuppressWarnings("nullness") // b/192354773 in our checker affects toArray declarations
    public <T extends @Nullable Object> T[] toArray(T[] array) {
      return standardToArray(array);
    }
  }

        default:
          /*
           * The suppression is safe because we ensure that the first `distinct` elements have been
           * populated.
           */
          @SuppressWarnings("nullness")
          Object[] elements =
              (distinct == dedupedElements.length)
                  ? dedupedElements
                  : Arrays.copyOf(dedupedElements, distinct);

      default:
        /*
         * The suppression is safe because the callers promise to put non-null objects in the first
         * `length` array elements.
         */
        @SuppressWarnings("nullness")
        Object[] elementsWithoutTrailingNulls =
            length < elements.length ? Arrays.copyOf(elements, length) : elements;
        return new RegularImmutableList<>(elementsWithoutTrailingNulls);
    }
  }