JSON scalar type

Author: jturkel

guides/type_definitions/scalars.md

@@ -16,6 +16,7 @@ Scalars are "leaf" values in GraphQL. There are several built-in scalars, and yo
 - `Boolean`, like a JSON or Ruby boolean (`true` or `false`)
 - `ID`, which a specialized `String` for representing unique object identifiers
 - `ISO8601DateTime`, an ISO 8601-encoded datetime
+- `JSON`, like JSON or Ruby hashes, arrays, strings, integers, floats, booleans and nils. This should be used judiciously because it subverts the GraphQL type system.
 
 Fields can return built-in scalars by referencing them by name:
 
@@ -34,6 +35,8 @@ field :is_top_ranked, Boolean, null: false
 field :id, ID, null: false
 # ISO8601DateTime field
 field :created_at, GraphQL::Types::ISO8601DateTime, null: false
+# JSON field
+field :parameters, GraphQL::Types::JSON, null: false
 ```
 
 Custom scalars (see below) can also be used by name:

lib/graphql/types.rb

@@ -4,5 +4,6 @@
 require "graphql/types/id"
 require "graphql/types/int"
 require "graphql/types/iso_8601_date_time"
+require "graphql/types/json"
 require "graphql/types/string"
 require "graphql/types/relay"

lib/graphql/types/json.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+module GraphQL
+  module Types
+    # An untyped JSON scalar that maps to Ruby hashes, arrays, strings, integers, floats, booleans and nils.
+    # This should be used judiciously because it subverts the GraphQL type system.
+    #
+    # Use it for fields or arguments as follows:
+    #
+    #     field :template_parameters, GraphQL::Types::JSON, null: false
+    #
+    #     argument :template_parameters, GraphQL::Types::JSON, null: false
+    #
+    class JSON < GraphQL::Schema::Scalar
+      description "Represents untyped JSON"
+
+      def self.coerce_input(value, _context)
+        value
+      end
+
+      def self.coerce_result(value, _context)
+        value
+      end
+    end
+  end
+end

spec/support/jazz.rb

@@ -249,16 +249,6 @@ def self.coerce_result(val, ctx)
     end
   end
 
-  class RawJson < GraphQL::Schema::Scalar
-    def self.coerce_input(val, ctx)
-      val
-    end
-
-    def self.coerce_result(val, ctx)
-      val
-    end
-  end
-
   class Musician < BaseObject
     implements GloballyIdentifiableType
     implements NamedEntity
@@ -358,12 +348,12 @@ def now_playing; Models.data["Ensemble"].first; end
     field :inspect_context, [String], null: false
     field :hashyEnsemble, Ensemble, null: false
 
-    field :echo_json, RawJson, null: false do
-      argument :input, RawJson, required: true
+    field :echo_json, GraphQL::Types::JSON, null: false do
+      argument :input, GraphQL::Types::JSON, required: true
     end
 
-    field :echo_first_json, RawJson, null: false do
-      argument :input, [RawJson], required: true
+    field :echo_first_json, GraphQL::Types::JSON, null: false do
+      argument :input, [GraphQL::Types::JSON], required: true
     end
 
     field :upcase_check_1, String, null: true, resolver_method: :upcase_check, extras: [:upcase]