[augeas-devel] ruby-augeas: fine grained exceptions

[Ionuț Arțăriși]

On 11/16/2011 01:28 AM, David Lutterkort wrote:
> Hi Ionut,
>
> On Tue, 2011-11-08 at 14:25 +0100, Ionuț Arțăriși wrote:
>> I was annoyed at the fact that most augeas errors pass silently, only
>> returning an error code, which meant having to check after each command
>> if there actually was an error. I think that behaviour is very C-like
>> and not very ruby like. Instead I think the user should be prompted
>> immediately when an error happened and which kind of error it was.
> I agree with that sentiment, and really like your patches - excellent
> code, great tests, and overall a great improvement of the bindings.
>
> There's one fly in the ointment: they are not backwards compatible; in
> particular, they will cause huge headaches for puppet, since any code
> that uses the bindings right now is not prepared to expect exceptions.
> In addition, the patches do away with some of the exception-throwing '!'
> variants, again breaking backwards compatibility.
>
> At the same time, I _really_ like what the bindings look like with your
> changes. To preserve backwards compatibility, how about we rename the
> existing Augeas class to AugeasOld or similar.
>
> We then add a new Augeas class, making sure that Augeas::open returns an
> instance of AugeasOld, and mention in the docs that Augeas::open is
> deprecated. Add a method Augeas::create(opts = {}) that is more Ruby-ish
> than open, i.e. lets you write
>
>          Augeas::create(:root =>  "/tmp", :loadpath =>  "/some/where", :noload =>  true, :save_mode =>  :noop)
>
Cool, I like this approach.
>> There are some issues remaining, mostly around the load and save
>> commands which seem to have quite a different policy about errors
>> (1. storing them in the augeas tree, 2. returning success when failing
>> in case of load), but that should be a different issue.
> It would be nice to help with translating matches for /augeas//error
> into more Rubyish objects, maybe with a helper call that produces a
> struct from the fields stored for each file under /augeas/files
>
Ok, I'll look more into this after fixing the first issue.

I've been mostly busy with other stuff until now, but I hope I'll have 
more time to work on this next week.

Thanks a lot for your feedback!

-Ionuț