blob: 71f5da9df279f94344996ea5260174a94c4268d2 [file] [log] [blame]
* Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file
* for details. All rights reserved. Use of this source code is governed by a
* BSD-style license that can be found in the LICENSE file.
* @assertion const JsonCodec({dynamic reviver(key,value),
* dynamic toEncodable(object)})
* Creates a JsonCodec with the given reviver and encoding function.
* ...
* The toEncodable function is used during encoding. It is invoked for values
* that are not directly encodable to a string (a value that is not a number,
* boolean, string, null, list or a map with string keys). The function must
* return an object that is directly encodable. The elements of a returned list
* and values of a returned map do not need to be directly encodable, and if
* they aren't, toEncodable will be used on them as well. Please notice that it
* is possible to cause an infinite recursive regress in this way, by
* effectively creating an infinite data structure through repeated call to
* toEncodable.
* @description Checks that this constructor, called with toEncodable parameter,
* creates object with toEncodable function which is used during encoding
* @author
import "dart:convert";
import "../../../Utils/expect.dart";
class A {
Object toJson() => 42;
class C {
String toJson() => "C: this is JSON";
dynamic toEncodable(object) {
if (object is A) {
return "A encoded by toEncodable";
if (object is C) {
return "C encoded by toEncodable";
return "Another encoded by toEncodable";
checkEncodable(JsonCodec codec, var object, var expected) {
String encoded = codec.encode(object);
Expect.equals(expected, encoded);
main() {
JsonCodec codec = new JsonCodec(toEncodable: toEncodable);
checkEncodable(codec, 1, "1");
checkEncodable(codec, 3.14, "3.14");
checkEncodable(codec, null, "null");
checkEncodable(codec, "str", '"str"');
checkEncodable(codec, true, 'true');
checkEncodable(codec, false, 'false');
checkEncodable(codec, [1, 2, 3], "[1,2,3]");
checkEncodable(codec, {"a": "b"}, '{"a":"b"}');
checkEncodable(codec, new A(), '"A encoded by toEncodable"');
checkEncodable(codec, new C(), '"C encoded by toEncodable"');
checkEncodable(codec, [new C(), new A()],
'["C encoded by toEncodable","A encoded by toEncodable"]');
// Map with not a string keys
checkEncodable(codec, {new C(): new A()}, '"Another encoded by toEncodable"');
// Map with a string keys
checkEncodable(codec, {"x": new A()}, '{"x":"A encoded by toEncodable"}');