IsEmpty doesn't seem to work on Object Collections

[taigrr]

What is the current bug behavior?

I have a server returning the following JSON:
{ "a":{ "b":{ "c":{}, "d":{} } } }

And I have a hurl file with the following assertions:

# request endpoint:
POST http://server/request
{
   "x":"y",
   "z":420
}
HTTP 200
[Asserts]
jsonpath "$.a.b.c" != null
jsonpath "$.a.b.c" isCollection
jsonpath "$.a.b.c" isEmpty

1. Set up a server to return that response
2. Hit it with hurl hurl --test *.hurl
3. See an assertion failure:

test.hurl: Running [1/1]
error: Assert failure
  --> test.hurl:11:0
   |
13 | jsonpath "$.a.b.c" isEmpty
   |   actual:   object
   |   expected: count equals to 0
   |   >>> types between actual and expected are not consistent
   |


test.hurl: Failure (1 request(s) in 2 ms)
--------------------------------------------------------------------------------
Executed files:  1
Succeeded files: 0 (0.0%)
Failed files:    1 (100.0%)
Duration:        2 ms

According to the documentation:

isEmpty	Query returns an empty collection	jsonpath "$.movies" isEmpty

Since isCollection returns true, my c object is a collection. It's clearly empty, why am I getting a type error?

What is the expected correct behavior?

I should not get a type error

Execution context

hurl 4.0.0 libcurl/8.2.0 OpenSSL/3.1.1 zlib/1.2.13 brotli/1.0.3840 zstd/1.5.5 libidn2/2.3.4 libssh2/1.11.0 nghttp2/1.55.1
Features (libcurl): alt-svc AsynchDNS brotli HSTS HTTP2 IDN IPv6 Largefile libz NTLM NTLM_WB SPNEGO SSL TLS-SRP UnixSockets zstd
Features (built-in): brotli

archlinux, 6.4.4-arch1-1 #1 SMP PREEMPT_DYNAMIC Wed, 19 Jul 2023 19:19:38 +0000 x86_64 GNU/Linux

Possible fixes

It's possible isEmpty only works for arrays/slices, not all collection types, it looks to me like it's just implemented as an alias to count == 0. Probably need to do a type check and have multiple codepaths instead.

[jcamiel]

Hi @taigrr thanks for you detailed report. It's effectively a bug, isEmpty should have been OK in this case.

[jcamiel]

Thanks @taigrr for the issue, it should be fixed on master, you can test it if you know how to build a Rust application (see => Build & Test) or wait for the next Hurl release landing in September. One thing that we can improve (I just need to check with @fabricereix) is do we allow count on an object ?

POST http://server/request
{
   "x":"y",
   "z":420
}
jsonpath "$.a.b.c" != null       # OK
jsonpath "$.a.b.c" isCollection  # OK
jsonpath "$.a.b.c" isEmpty       # OK
jsonpath "$.a.b.c" count == 0    # ??

[taigrr]

Thanks! For my personal use case I am ok with this as-is, and I don't know of a use case for count on an object. I could check individual properties on the object, or I would want to know if it's null or empty or non-empty, but I don't know a real-world use case for count.