tests/test_json_deserialization_heuristic.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #     http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 # See the License for the specific language governing permissions and
  13 # limitations under the License.
  14
  15 import json
  16 import json::static
  17
  18 class MyData
  19         serialize
  20
  21         var data: String
  22
  23         redef fun to_s do return "<MyData {data}>"
  24 end
  25
  26 class MyError
  27         serialize
  28
  29         var error: String
  30
  31         redef fun to_s do return "<MyError {error}>"
  32 end
  33
  34 class MyJsonDeserializer
  35         super JsonDeserializer
  36
  37         redef fun class_name_heuristic(json_object)
  38         do
  39                 if json_object.keys.has("error") then return "MyError"
  40                 if json_object.keys.has("data") then return "MyData"
  41                 return null
  42         end
  43 end
  44
  45 var tests = new Array[String]
  46
  47 # Object with meta data, does not need the heuristic
  48 tests.add """
  49 {"__class": "MyData", "data": "some data"}"""
  50
  51 # Objects without meta data
  52 tests.add """
  53 {"data": "some other data"}"""
  54 tests.add """
  55 {"error": "some error message"}"""
  56
  57 for o in tests do
  58         var deserializer = new MyJsonDeserializer(o)
  59         var deserialized = deserializer.deserialize
  60
  61         print "# JSON: {o}"
  62         if deserializer.errors.not_empty then print "# Errors: '{deserializer.errors.join("', '")}'"
  63         print "# Nit: {deserialized or else "null"}\n"
  64 end