hobby-json-keys is a Hobby extension to parse JSON requests. It is available on Rubygems at hobby-json-keys.

After including it into your app, you can use the key method to define which keys will be accepted by the app. To access these keys, you can use keys(a Ruby Hash) in your routes.

require 'hobby'
require 'hobby/json/keys'

class App
  include Hobby
  include JSON::Keys

  # This defines that 'fn' and 'in' must be present
  # in every request body. Otherwise: 400, bad request.
  key :fn
  key :in

  # The route definition for POST requests is below
  post {
    keys # => { fn:, in: }
         # a Hash with the defined keys
    
    # The latest object here gets converted #to_json
    # and sent back as a response.
  }
end

With one argument(key :name), it will check only the key presence.

With two arguments(key :name, type), it will also check that the key's value has an appropriate type. Any object that implements .=== can be used as a type.

"", [], {} will be rejected if you define the keys as follows:

key :some_string, String
key :some_array, Array
key :some_hash, Hash

To accept empty values, you can extend the types as follows:

key :some, String {
  may_be_empty
}

By default, all defined keys are required. You can define optional ones inside of the optional block:

key :fn

optional {
  key :in
}

To build the project and run the tests:

bundle exec rake