Workaround for nullable MSON attributes in Dredd Ruby and Node.js hooks

apiary.apib

# My API

# My Resource [/my_resource]

# Its Action [GET]

+ Response 200 (application/json)

  + Attributes (My Structure)

# Data Structures

## My Structure (object)

- myKey: myValue (string)
- destination:  (object, nullable, optional) - Some description #nullable
- someObject: (object)
  - itsKey: (string, nullable, optional) - Some other description #nullable

hooks.rb

require 'json'
include DreddHooks::Methods

# Recursively add null as acceptable type if there is string
# "#nullable" present in the property description
def patch_properties_with_nullable schema
  if !schema['description'].nil?
    if schema['description'].include? "#nullable"
      if schema['type'].nil?
        schema['type'] = 'null'
      elsif schema['type'].is_a? String
        schema['type'] = [schema['type'], 'null']
      elsif schema['type'].is_a? Array
        schema['type'].push 'null'
      end
    end
  end

  if schema['properties'].is_a? Hash
    schema['properties'].each do |key, value|
      schema['properties'][key] = patch_properties_with_nullable value
    end
  end
  schema
end

before_all do |transactions|
  transactions.each_with_index do |transaction, index|
    if ! transaction['expected']['bodySchema'].nil?
      schema = JSON.parse transaction['expected']['bodySchema']
      schema = patch_properties_with_nullable schema
      transactions[index]['expected']['bodySchema'] = schema.to_json
    end
  end
end

run-dredd.sh

#!/bin/sh

dredd apiary.apib http://localhost:3000 --hookfiles=./hooks.rb --language ruby

schema-after.json

{
  "type":"object",
  "properties":{
    "myKey":{
      "type":"string"
    },
    "destination":{
      "type":[
        "object",
        "null"
      ],
      "description":"Some description #nullable"
    },
    "someObject":{
      "type":"object",
      "properties":{
        "itsKey":{
          "type":[
            "string",
            "null"
          ],
          "description":"Some other description #nullable"
        }
      }
    }
  },
  "$schema":"http://json-schema.org/draft-04/schema#"
}

schema-before.json

{
  "type": "object",
  "properties": {
    "myKey": {
      "type": "string"
    },
    "destination": {
      "type": "object",
      "description": "Some description #nullable"
    },
    "someObject": {
      "type": "object",
      "properties": {
        "itsKey": {
          "type": "string",
          "description": "Some other description #nullable"
        }
      }
    }
  },
  "$schema": "http://json-schema.org/draft-04/schema#"
}