blob: d4f61b56c5082a36cbe5f3274a7420b29bc2ea9d [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.
/// @assertionconst JsonEncoder.withIndent(
/// String indent, [
/// dynamic toEncodable(
/// nonSerializable
/// )
/// ])
/// Creates a JSON encoder that creates multi-line JSON.
/// The encoding of elements of lists and maps are indented and put on separate
/// lines. The indent string is prepended to these elements, once for each level
/// of indentation.
/// If indent is null, the output is encoded as a single line.
/// The JSON encoder handles numbers, strings, booleans, null, lists and maps
/// directly.
/// Any other object is attempted converted by toEncodable to an object that is
/// of one of the convertible types.
/// If toEncodable is omitted, it defaults to calling .toJson() on the object.
/// @description Checks that this constructor, called with not null indent
/// parameter and toEncodable creates a JSON encoder that creates multi-line
/// JSON.
/// @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";
check(JsonEncoder encoder, var object, var expected) {
String encoded = encoder.convert(object);
Expect.equals(expected, encoded);
main() {
JsonEncoder encoder = new JsonEncoder.withIndent("--", toEncodable);
check(encoder, new A(), '"A encoded by toEncodable"');
check(encoder, new C(), '"C encoded by toEncodable"');
check(encoder, 1, "1");
check(encoder, 3.14, "3.14");
check(encoder, null, "null");
check(encoder, "str", '"str"');
check(encoder, true, 'true');
check(encoder, false, 'false');
check(encoder, [1, 2, 3], "[\n--1,\n--2,\n--3\n]");
check(encoder, {"a": "b"}, '{\n--"a": "b"\n}');