JSON parser rejects valid JSON with empty keys in objects

[badboy]

What is the current bug behavior?

JSON with empty keys ({ "": "value" }) is rejected with an error:

expecting an element; found empty element instead

Steps to reproduce

Run this request:

POST https://api.codapi.org/v1/exec
content-type: application/json
origin: https://codapi.org
{
    "sandbox": "python",
    "command": "run",
    "files": {
        "": "print('hello world')"
    }
}

fails with:

error: Parsing JSON
  --> example-request.hurl:8:9
   |
 8 |         "": "print('hello world')"
   |         ^ expecting an element; found empty element instead
   |

What is the expected correct behavior?

Request executes correctly, as empty keys in JSON are allowed.
This workaround works:

POST https://api.codapi.org/v1/exec
content-type: application/json
origin: https://codapi.org
```
{
    "sandbox": "python",
    "command": "run",
    "files": {
        "": "print('hello world')"
    }
}
```

$ hurl request.hurl
{"id":"python_run_f2057eb8","ok":true,"duration":273,"stdout":"hello world","stderr":""}

Execution context

❯ hurl --version
hurl 4.3.0 (aarch64-apple-darwin23.5.0) libcurl/8.7.1 OpenSSL/3.0.13 zlib/1.3.1 brotli/1.1.0 zstd/1.5.6 libidn2/2.3.7 libssh2/1.11.0 nghttp2/1.61.0
Features (libcurl):  alt-svc AsynchDNS brotli HSTS HTTP2 IDN IPv6 Largefile libz NTLM SPNEGO SSL TLS-SRP UnixSockets zstd
Features (built-in): brotli

Possible fixes

[fabricereix]

Thanks @badboy for reporting the bug.
An empty key is indeed valid JSON.
We will fix it for the next release.