private Description checkOverriding()

in nullaway/src/main/java/com/uber/nullaway/NullAway.java [1094:1144]
45 lines of code
7 McCabe index (conditional complexity)

  private Description checkOverriding(
      Symbol.MethodSymbol overriddenMethod,
      Symbol.MethodSymbol overridingMethod,
      @Nullable MemberReferenceTree memberReferenceTree,
      VisitorState state) {
    // if the super method returns nonnull, overriding method better not return nullable
    // Note that, for the overriding method, the permissive default is non-null,
    // but it's nullable for the overridden one.
    if (overriddenMethodReturnsNonNull(
            overriddenMethod, overridingMethod.owner, memberReferenceTree, state)
        && getMethodReturnNullness(overridingMethod, state, Nullness.NONNULL)
            .equals(Nullness.NULLABLE)
        && (memberReferenceTree == null
            || getComputedNullness(memberReferenceTree).equals(Nullness.NULLABLE))) {
      String message;
      if (memberReferenceTree != null) {
        message =
            "referenced method returns @Nullable, but functional interface method "
                + ASTHelpers.enclosingClass(overriddenMethod)
                + "."
                + overriddenMethod.toString()
                + " returns @NonNull";
      } else {
        message =
            "method returns @Nullable, but superclass method "
                + ASTHelpers.enclosingClass(overriddenMethod)
                + "."
                + overriddenMethod.toString()
                + " returns @NonNull";
      }

      Tree errorTree =
          memberReferenceTree != null
              ? memberReferenceTree
              : getTreesInstance(state).getTree(overridingMethod);
      return errorBuilder.createErrorDescription(
          new ErrorMessage(MessageTypes.WRONG_OVERRIDE_RETURN, message),
          buildDescription(errorTree),
          state,
          overriddenMethod);
    }
    // if any parameter in the super method is annotated @Nullable,
    // overriding method cannot assume @Nonnull
    return checkParamOverriding(
        overridingMethod.getParameters(),
        overriddenMethod,
        null,
        memberReferenceTree,
        state,
        overridingMethod);
  }