if statement for external condition

[gulnarrra]

I have a common list of rules. But I don't have to check my config with all the rules. It depends on conditions. And this condition is located at the same config, but in different structure. Is it possible to make such validations?
Example:
My config to be validated:

{
  "/tmp/europe.yml": {
    "raw": "conf:\n  iscontinent: true\n  cities: [\"Dehli\", \"Paris\"]\n\n",
    "structure": {
      "conf": {
        "iscontinent": true,
        "cities": [
          "Dehli",
          "Paris"
        ]
      }
    }
  },
  "/tmp/africa.yml": {
    "raw": "conf:\n  iscontinent: true\n  cities: [\"Addis-Abeba\", \"Nairobi\", \"Paris\"]\n  ",
    "structure": {
      "conf": {
        "iscontinent": true,
        "cities": [
          "Addis-Abeba",
          "Nairobi",
          "Paris"
        ]
      }
    }
  },
  conf: {
    check_africa: true
    ckeck_europe: false
  }
}

I'd like to check "/tmp/africa.yml"."structure"."conf"."cities" list only if "conf"."check_africa" is set to "true".
And my rules code can be like this:

package verifylist
import "list"
// here some "if" statement like this:
// if conf.check_africa == true 
[=~"/tmp/africa.yml"]: structure!: conf!: {
  ...
  cities!: list.Contains("Nairobi")
}

Is it possible? How can I refer to data from outer / external config file?

[myitcv]

Hi @gulnarrra and welcome!

Yes, this is possible. But the identifier conf needs to be in scope in the CUE file.

Consider the following example:

# Good data
exec cue vet verifylist.cue good.json

# Bad data
! exec cue vet verifylist.cue bad.json
cmp stderr stderr.golden

-- verifylist.cue --
package verifylist

import "list"

// Assert that the data we validate against will contain a
// conf field with the given schema
conf!: {
	check_africa: bool
	ckeck_europe: bool
}

if conf.check_africa {
	("/tmp/africa.yml")?: structure!: conf!: cities!: list.Contains("Nairobi")
}

-- good.json --
{
  "/tmp/europe.yml": {
    "raw": "conf:\n  iscontinent: true\n  cities: [\"Dehli\", \"Paris\"]\n\n",
    "structure": {
      "conf": {
        "iscontinent": true,
        "cities": [
          "Dehli",
          "Paris"
        ]
      }
    }
  },
  "/tmp/africa.yml": {
    "raw": "conf:\n  iscontinent: true\n  cities: [\"Addis-Abeba\", \"Nairobi\", \"Paris\"]\n  ",
    "structure": {
      "conf": {
        "iscontinent": true,
        "cities": [
          "Addis-Abeba",
          "Nairobi",
          "Paris"
        ]
      }
    }
  },
  "conf": {
    "check_africa": true,
    "ckeck_europe": false
  }
}
-- bad.json --
{
  "/tmp/europe.yml": {
    "raw": "conf:\n  iscontinent: true\n  cities: [\"Dehli\", \"Paris\"]\n\n",
    "structure": {
      "conf": {
        "iscontinent": true,
        "cities": [
          "Dehli",
          "Paris"
        ]
      }
    }
  },
  "/tmp/africa.yml": {
    "raw": "conf:\n  iscontinent: true\n  cities: [\"Addis-Abeba\", \"Nairobi\", \"Paris\"]\n  ",
    "structure": {
      "conf": {
        "iscontinent": true,
        "cities": [
          "Addis-Abeba",
          "Paris"
        ]
      }
    }
  },
  "conf": {
    "check_africa": true,
    "ckeck_europe": false
  }
}
-- stderr.golden --
"/tmp/africa.yml".structure.conf.cities: invalid value ["Addis-Abeba","Paris"] (does not satisfy list.Contains("Nairobi")):
    ./verifylist.cue:13:52
    ./bad.json:19:19
    ./verifylist.cue:13:66

[gulnarrra]

Hi,
and what if data a little bit complicated, and we have to use regexp? How to refer a field with regexp? Example: inside "conf" structure can be anything starting with "app": app-123, app-456, app-xyz.

-- bad.json --
{
  "/tmp/europe.yml": {
    "structure": {
      "conf": {
        "cities": [
          "Dehli",
          "Paris"
        ]
      }
    }
  },
  "/tmp/africa.yml": {
    "structure": {
      "conf": {
        "cities": [
          "Addis-Abeba",
          "Paris"
        ]
      }
    }
  },
  "conf": {
    "app-123": {
      "check_africa": true,
      "check_europe": false
    }
  }
}

-- verifylist.cue --
package verifylist

import "list"

app!: {
  conf="conf.+"!: {
        check_africa: bool
        check_europe: bool
  }
}
if app.conf.check_africa {
        ("/tmp/africa.yml")?: structure!: conf!: cities!: list.Contains("Nairobi")
}

1. I can't use alias because I get error "unreferenced alias":

$ cue vet verifylist.cue bad.json
app: unreferenced alias or let clause conf:
    ./verifylist.cue:6:3

2. I can't use regexp inside "if" statement like this if "app.conf.+.check_africa", because I get type error:

$ cue vet verifylist.cue bad.json
cannot use "app.conf.+.check_africa" (type string) as type bool:
    ./verifylist.cue:11:1
    ./verifylist.cue:11:4

Please, help)