bug#72941: jsonrpc: Check if parameters are in line with the spec

bug#72941: jsonrpc: Check if parameters are in line with the spec

[Felician Nemeth]

I failed to implement an LSP extension to Eglot, because my function
sent a required parameter as a string instead of an array containing a
single element: the string.  In the end it turned out that this was my
fault, because according to the JSON specification: "If present,
parameters for the rpc call MUST be provided as a Structured
value. Either by-position through an Array or by-name through an
Object."  https://www.jsonrpc.org/specification#parameter_structures

Would it be possible to extend jsonrpc.el to check the params argument
of jsonrpc-request, jsonrpc-notify, and jsonrpc-async-request whether it
is a structured value?  And if it is not, then guide the programmer to
the above URL with a warning.

Thank you.

(Background: <https://github.com/ocaml/ocaml-lsp/issues/1330>)

bug#72941: jsonrpc: Check if parameters are in line with the spec

[Eli Zaretskii]

> Cc: Daniel Pettersson <daniel@dpettersson.net>
> From: Felician Nemeth <nemethf@tmit.bme.hu>
> Date: Sun, 01 Sep 2024 18:26:02 +0200
> 
> I failed to implement an LSP extension to Eglot, because my function
> sent a required parameter as a string instead of an array containing a
> single element: the string.  In the end it turned out that this was my
> fault, because according to the JSON specification: "If present,
> parameters for the rpc call MUST be provided as a Structured
> value. Either by-position through an Array or by-name through an
> Object."  https://www.jsonrpc.org/specification#parameter_structures
> 
> Would it be possible to extend jsonrpc.el to check the params argument
> of jsonrpc-request, jsonrpc-notify, and jsonrpc-async-request whether it
> is a structured value?  And if it is not, then guide the programmer to
> the above URL with a warning.
> 
> Thank you.
> 
> (Background: <https://github.com/ocaml/ocaml-lsp/issues/1330>)

Adding João.

bug#72941: jsonrpc: Check if parameters are in line with the spec

[Daniel Pettersson]

>> Would it be possible to extend jsonrpc.el to check the params argument
>> of jsonrpc-request, jsonrpc-notify, and jsonrpc-async-request whether it
>> is a structured value?  And if it is not, then guide the programmer to
>> the above URL with a warning.

The use case makes sense to me, but I would go with updating the docs
rather then the API.  The current wording could use some love as it's
refereed to as JSON object or plist (at different functions).  When it
should be plist or vector, where we could throw in a link to the
specification.

I am not for signaling an error or similar as it's a breaking change in
my book, which does not seam called for in this case.

/Daniel Pettersson

bug#72941: jsonrpc: Check if parameters are in line with the spec

[Felician Nemeth]

>>> Would it be possible to extend jsonrpc.el to check the params argument
>>> of jsonrpc-request, jsonrpc-notify, and jsonrpc-async-request whether it
>>> is a structured value?  And if it is not, then guide the programmer to
>>> the above URL with a warning.
>
> The use case makes sense to me, but I would go with updating the docs
> rather then the API.  The current wording could use some love as it's
> refereed to as JSON object or plist (at different functions).  When it
> should be plist or vector, where we could throw in a link to the
> specification.

Makes sense.

> I am not for signaling an error or similar as it's a breaking change in
> my book, which does not seam called for in this case.

Maybe when the server responds with an error to a jsonrpc-request, then
jsonrpc.el could create an additional warning if the params of the
request was not structured.  Or maybe it is too much work for a very
small gain.

Thank you.