[tarantool-patches] Re: [PATCH v2 3/3] lua-yaml: treat an empty document/value as null

[Vladislav Shpilevoy <v.shpilevoy@tarantool.org>]

Thanks for the patch!

On 22/01/2019 05:12, Alexander Turenko wrote:
> It improves our compatibility with the YAML standard.
> 
> yaml.encode('') result changed from
> 
> ---
> ...
> 
> to
> 
> --- ''
> ...
> 
> yaml.decode('') returns zero values count before, now it returns
> box.NULL. yaml.decode('- ') returns {''} before, now {box.NULL}.
> 
> This commit touches many tests and test result files, which use console,
> without behaviour changes. It also adds two test cases to
> app-tap/console.test.lua.

Not sure if it makes sense listing factual changes here, because
literally the same I see below and in "git diff --stat".

> ---
>   test/app-tap/console.test.lua   |   16 +-
>   test/app/fio.result             |    2 +-
>   test/app/socket.result          |   26 +-
>   test/box/access.result          |    8 +-
>   test/box/role.result            |    8 +-
>   test/box/sequence.result        |    2 +-
>   test/vinyl/errinj_tx.result     |   10 +-
>   test/vinyl/hermitage.result     |  122 ++--
>   test/vinyl/mvcc.result          | 1066 +++++++++++++++----------------
>   test/vinyl/mvcc.test.lua        |    4 +-
>   test/vinyl/tx_conflict.result   |    2 +-
>   test/vinyl/tx_conflict.test.lua |    2 +-
>   test/vinyl/tx_gap_lock.result   |  189 +++---
>   test/vinyl/tx_gap_lock.test.lua |    3 +-
>   test/vinyl/tx_serial.result     |    2 +-
>   test/vinyl/tx_serial.test.lua   |    2 +-
>   third_party/lua-yaml/lyaml.cc   |   22 +-
>   17 files changed, 747 insertions(+), 739 deletions(-)
> 
> diff --git a/test/vinyl/mvcc.result b/test/vinyl/mvcc.result
> index 1941744b9..db7fc8e83 100644
> --- a/test/vinyl/mvcc.result
> +++ b/test/vinyl/mvcc.result
> @@ -41,29 +41,29 @@ t = box.space.test
>   --
>   c1:begin()
>   ---
> -- 
> +- null

How about to start returning nothing instead of returning null so
as to do not change the tests (or at least make the diff smaller)?

I see, that most of the diff is from txn_proxy, which always does
return 'something'. You can change it so as to do not just return, but
check if a result is not null, and only then return. Otherwise do nothing
or empty return.

I am sure it will work since space:get(), for example, still can
return nothing (!= null), and this is why other tests didn't fail.