JSON type support

lib/graphQl/joiConverter.js

@@ -2,8 +2,33 @@
 const joiConverter = module.exports = { }
 
 const graphQl = require('graphql')
+const {Kind} = require('graphql/language')
 const readTypes = require('./readTypes.js')
 
+// Custom GraphQL object to handle arbitrary JSON blobs
+// https://stackoverflow.com/questions/45598812/graphql-blackbox-any-type
+const ObjectScalarType = new graphQl.GraphQLScalarType({
+  name: 'Object',
+  description: 'Arbitrary object',
+  parseValue: (value) => {
+    return typeof value === 'object' ? value
+      : typeof value === 'string' ? JSON.parse(value)
+        : null
+  },
+  serialize: (value) => {
+    return typeof value === 'object' ? value
+      : typeof value === 'string' ? JSON.parse(value)
+        : null
+  },
+  parseLiteral: (ast) => {
+    switch (ast.kind) {
+      case Kind.STRING: return JSON.parse(ast.value)
+      case Kind.OBJECT: throw new Error(`Not sure what to do with OBJECT for ObjectScalarType`)
+      default: return null
+    }
+  }
+})
+
 joiConverter.simpleAttribute = joiScheme => {
   let type = joiScheme._type
   if (type === 'any') {
@@ -16,6 +41,9 @@ joiConverter.simpleAttribute = joiScheme => {
   if (type === 'number') {
     type = 'float'
   }
+  if (type === 'json') {
+    return ObjectScalarType
+  }
 
   if (type === 'array') {
     if (joiScheme._inner.items.length === 1) {