Invalid JSONPath when using != (not equal) operator

[quantonganh]

What is the current bug behavior?

Given the following response:

{
    "data": [
        {
            "id": 1
        },
        {
            "id": 2
        }
    ]
}

If I want to get the first item with id equal to 1:

[Captures]
id: jsonpath "$.data[?(@.id == 1)].id" nth 0

This successfully returns:

* Captures:
* id: 1

However, when I attempt to get the first item with an id not equal to 1:

id: jsonpath "$.data[?(@.id != 1)].id" nth 0

I encounter the following error:

error: Invalid JSONPath
  --> test.hurl:4:14
   |
   | GET http://localhost:8888/api/v1/items
   | ...
 4 | id: jsonpath "$.data[?(@.id != 1)].id" nth 0
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^ the JSONPath expression '$.data[?(@.id != 1)].id' is not valid
   |

What is the expected correct behavior?

The expression should return:

* Captures:
* id: 2

Execution context

• Hurl Version (hurl --version):

$ hurl --version
hurl 5.0.1 (x86_64-apple-darwin21.0) libcurl/7.79.1 (SecureTransport) LibreSSL/3.3.5 zlib/1.2.11 nghttp2/1.45.1
Features (libcurl):  alt-svc AsynchDNS HSTS HTTP2 IPv6 Largefile libz NTLM NTLM_WB SPNEGO SSL UnixSockets
Features (built-in): brotli

[lepapareil]

Doesn't work either using $.data[?(!(@.id == 1))] :

 4 | id: jsonpath "$.data[?(!(@.id == 1))]" nth 0
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^ the JSONPath expression '$.data[?(!(@.id == 1))]' is not valid

or $.data[?(@.id < 1 || @.id > 1)] :

 4 | id: jsonpath "$.data[?(@.id < 1 || @.id > 1)]" nth 0
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the JSONPath expression '$.data[?(@.id < 1 || @.id > 1)]' is not valid

[fabricereix]

Thanks @quantonganh for your issue.
The support for filter is indeed quite limited.
But we should definitely work on it.
There is now a spec that we can follow.