Create list from array for Evaluation

[cartyc]

Hi!

Have a fun Rego question for the community. I am trying to evaluate a list of JSON array to confirm a specific object has a requited name and haven't figured out how to grab it successfully yet. I was wondering how it might be possible to make a list of the values from the array and then evaluate that list to see if the name exists.

The array looks roughly like this

{
"data":[
         {
          "name": "resource",
 		  "resource":{
            "data":{
              "name":"good-eval-name", <-- This is what I want to capture in a list for evaluation
            }
           }
         },
                  {
          "name": "resource",
 		  "resource":{
            "data":{
              "name":"bad-eval-name", <-- This is what I want to capture in a list for evaluation
            }
           }
         }
     ],
}

In this case I would be wanting to confirm the resource has a data array with the name good-eval-name.

The above example should pass and the below should fail.

{
"data":[
         {
          "name": "resource",
 		  "resource":{
            "data":{
              "name":"bad-eval-name", 
            }
           }
         },
                  {
          "name": "resource",
 		  "resource":{
            "data":{
              "name":"also-bad-eval-name", 
            }
           }
         }
     ],
}

thanks!

[anderseknert]

If you want to aggregate an array of the resource names, you could either use an array comprehension, like:

import future.keywords.in

obj := {"data": [
	{
		"name": "resource",
		"resource": {"data": {"name": "good-eval-name"}},
	},
	{
		"name": "resource",
		"resource": {"data": {"name": "bad-eval-name"}},
	},
]}

resource_names := [name | some item in obj.data; name := item.resource.data.name]

Or you could use a partial rule to build a set of them:

resource_names[name] {
    some item in obj.data
    name := item.resource.data.name
}

(You could also use a set comprehension to achieve the same outcome, they are functionally equivalent)

Then simply use in to check for membership:

not "bad-eval-name" in resource_names

I'd probably choose to work with this as a set, since ordering doesn't seem to matter (and neither uniqueness).

Let me know if that answers your question or if I should elaborate on something :)

[cartyc]

Thanks @anderseknert !!! Just gave it a shot and it worked like a charm :)