Compiling a JSON schema -> Ruby fails when there are relative path $refs in the schema

[jwilmoth-nc]

https://www.shalerb.org/#compiling-json-and-xml-schema uses a simple example for generation that doesn't include $refs. Given a file that uses a simple relative path ref that exists in the same directory, the shaleb -c -i user.json command fails with the following message:

/Library/Ruby/Gems/2.6.0/gems/shale-1.0.0/lib/shale/schema/json_compiler.rb:184:in `resolve_ref': can't resolve reference 'http://example.com/schemas/common.json#/definitions/address' (Shale::SchemaError)
    from /Library/Ruby/Gems/2.6.0/gems/shale-1.0.0/lib/shale/schema/json_compiler.rb:310:in `compile'
    from /Library/Ruby/Gems/2.6.0/gems/shale-1.0.0/lib/shale/schema/json_compiler.rb:336:in `block in compile'
    from /Library/Ruby/Gems/2.6.0/gems/shale-1.0.0/lib/shale/schema/json_compiler.rb:335:in `each'
    from /Library/Ruby/Gems/2.6.0/gems/shale-1.0.0/lib/shale/schema/json_compiler.rb:335:in `compile'
    from /Library/Ruby/Gems/2.6.0/gems/shale-1.0.0/lib/shale/schema/json_compiler.rb:89:in `as_models'
    from /Library/Ruby/Gems/2.6.0/gems/shale-1.0.0/lib/shale/schema/json_compiler.rb:124:in `to_models'
    from /Library/Ruby/Gems/2.6.0/gems/shale-1.0.0/lib/shale/schema.rb:51:in `from_json'
    from /Library/Ruby/Gems/2.6.0/gems/shale-1.0.0/exe/shaleb:88:in `<top (required)>'
    from /usr/local/bin/shaleb:23:in `load'
    from /usr/local/bin/shaleb:23:in `<main>'

cat user.json| jq

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "http://example.com/schemas/user.json",
  "type": "object",
  "properties": {
    "firstName": {
      "type": "string"
    },
    "lastName": {
      "type": "string"
    },
    "address": {
      "$ref": "./common.json#/definitions/address"
    }
  }
}

cat common.json| jq

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "http://example.com/schemas/common.json",
  "definitions": {
    "address": {
      "type": "object",
      "properties": {
        "street": {
          "type": "string"
        },
        "city": {
          "type": "string"
        }
      }
    }
  }
}

[kgiszczak]

Hey Jon,

first thing is you are using Draft-07 JSON schema. Shale supports only Draft 2020-12. Second thing is $refs in JSON schema are not paths, they are just identifiers used to resolve references. You have to provide all the schema files that you're using.

Taken from https://json-schema.org/understanding-json-schema/structuring.html#id

Even though schemas are identified by URIs, those identifiers are not necessarily network-addressable. They are just identifiers. Generally, implementations don’t make HTTP requests (https://) or read from the file system (file://) to fetch schemas. Instead, they provide a way to load schemas into an internal schema database. When a schema is referenced by it’s URI identifier, the schema is retrieved from the internal schema database.

So working example would look like this:

shaleb -c -i user.json,common.json

And schema files:

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "http://example.com/schemas/user.json",
  "type": "object",
  "properties": {
    "firstName": {
      "type": "string"
    },
    "lastName": {
      "type": "string"
    },
    "address": {
      "$ref": "http://example.com/schemas/common.json#/$defs/address"
    }
  }
}

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "http://example.com/schemas/common.json",
  "$defs": {
    "address": {
      "type": "object",
      "properties": {
        "street": {
          "type": "string"
        },
        "city": {
          "type": "string"
        }
      }
    }
  }
}