Allow specifying deep additionalProperties=true

Author: SimenB

index.js

@@ -74,12 +74,26 @@ function build (schema, options) {
     ;
     return ${main}
   `
-  if (schema.additionalProperties === true) {
+  if (hasAdditionalPropertiesTrue(schema)) {
     return (new Function('fastSafeStringify', code))(fastSafeStringify)
   }
   return (new Function(code))()
 }
 
+function hasAdditionalPropertiesTrue (schema) {
+  if (schema.additionalProperties === true) { return true }
+
+  var objectKeys = Object.keys(schema)
+  for (var i = 0; i < objectKeys.length; i++) {
+    var value = schema[objectKeys[i]]
+    if (typeof value === 'object') {
+      if (hasAdditionalPropertiesTrue(value)) { return true }
+    }
+  }
+
+  return false
+}
+
 function $asNull () {
   return 'null'
 }

test/additionalProperties.test.js

@@ -237,3 +237,20 @@ test('very nested additionalProperties', (t) => {
   let obj = [{ ap: { nested: { moarNested: { finally: { value: 'str' } } } } }]
   t.equal('[{"ap":{"nested":{"moarNested":{"finally":{"value":"str"}}}}}]', stringify(obj))
 })
+
+test('nested additionalProperties set to true', (t) => {
+  t.plan(1)
+  const stringify = build({
+    title: 'nested additionalProperties=true',
+    type: 'object',
+    properties: {
+      ap: {
+        type: 'object',
+        additionalProperties: true
+      }
+    }
+  })
+
+  let obj = { ap: { value: 'string', someNumber: 42 } }
+  t.equal('{"ap":{"value":"string","someNumber":42}}', stringify(obj))
+})