Add isArray / isList predicate

[jcamiel]

Current predicate https://hurl.dev/docs/asserting-response.html#predicates can't distinguish between object and lists. There is a isCollection but it returns true for bytes, object, list, nodeset so we can't use it to differentiate object and list.

For instance:

{
  "fruits": {
    "name": "lemon"
  }
}

and

{
  "fruits": ["lemon"]
}

Both pass this assert:

GET https://localhost:fruits
HTTP 200
[Asserts]
jsonpath "$.fruits" isCollection

To do:

• choose name between isArray vs isList
• make clear in the docs what we call collections (bytes, list, nodeset, object)

[jcamiel]

@fabricereix @lepapareil do you prefer isArray or isList? I prefer myself isList it's a little more generalist and array may imply that the list is made of the same type of items which is not mandatory in JSON for instance...

[jcamiel]

More to think: I would prefer finally to split isCollection into isList and isObject (JSON objects and XML node set) and slowly deprecates isCollection...

[tbolon]

Tested on hurl 7.1.0: isCollection is accepted for jsonPath but not isList. The documentation states that isList should be used.

[jcamiel]

Hi @tbolon

Seems good on my side! I've just tested it on macOS (installed with brew):

$ hurl --version
hurl 7.1.0 (x86_64-apple-darwin24.0) libcurl/8.7.1 (SecureTransport) LibreSSL/3.3.6 zlib/1.2.12 nghttp2/1.64.0
Features (libcurl):  alt-svc AsynchDNS HSTS HTTP2 IPv6 Largefile libz NTLM SPNEGO SSL UnixSockets
Features (built-in): brotli

With this file:

GET https://httpbin.org/json
HTTP 200
[Asserts]
jsonpath "$.slideshow.slides" isList

And run:

$ hurl json.hurl
{
  "slideshow": {
    "author": "Yours Truly",
    "date": "date of publication",
    "slides": [
      {
        "title": "Wake up to WonderWidgets!",
        "type": "all"
      },
      {
        "items": [
          "Why <em>WonderWidgets</em> are great",
          "Who <em>buys</em> WonderWidgets"
        ],
        "title": "Overview",
        "type": "all"
      }
    ],
    "title": "Sample Slide Show"
  }
}

Could you share the Hurl file (and the response) that is not working on your side?

[tbolon]

You are right, I was using an old version of hurl for my tests, and used another installed version to check the version number. Sorry.

[jcamiel]

No pb, I'm relieved 😅!