Issue with conditional require of field if array contains a const

[andlbrei]

Hello!
I'm scratching my head a bit here, wondering why this isn't working.
Hopefully some of you can assist me in this issue, which I feel like I should have figured out by now...

This is a my schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "otherIncomeSource": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "otherIncomeSourceOtherComment": {
      "type": "string"
    }
  },
  "if": {
    "properties": {
      "otherIncomeSource": {
        "type": "array",
        "contains": {
          "const": "OTHER"
        }
      }
    }
  },
  "then": {
    "required": [
      "otherIncomeSourceOtherComment"
    ]
  }
}

When validating against an empty object I get an error:

Message:
    Required properties are missing from object: otherIncomeSourceOtherComment.
Schema path:
    #/then/required

If I set otherIncomeSource as required, and include it in the data as an empty array, then the if/else validates as expected.

What am I doing wrong?

I want otherIncomeSource to be optional, and if it is present and it has an item with the value OTHER, then I want the field otherIncomeSourceOtherComment to be required.

You can find an example here:
https://www.jsonschemavalidator.net/s/bx5E08xw

[jviotti]

Hey @andlbrei ,

The problem is on your if. Your check there is essentially saying that "if (if otherIncomeSource is defined and matches the given schema...)", but doesn't enforce otherIncomeSource to be present. Hence, an empty schema passes the if and you get into then, which forces otherIncomeSourceOtherComment to be required. Instead, you probably want to add required to your if as well, so that the empty instance doesn't pass:

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "otherIncomeSource": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "otherIncomeSourceOtherComment": {
      "type": "string"
    }
  },
  "if": {
    "required": [ "otherIncomeSource" ],
    "properties": {
      "otherIncomeSource": {
        "type": "array",
        "contains": {
          "const": "OTHER"
        }
      }
    }
  },
  "then": {
    "required": [
      "otherIncomeSourceOtherComment"
    ]
  }
}

Schemas can quickly get complicated. If it helps, what I typically do is use https://github.com/sourcemeta/jsonschema/blob/main/docs/test.markdown to write little unit tests for all the schemas I write.

[andlbrei]

Ah, great. I knew it would be simple... Thank you!