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// Copyright (c) 2020, 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.
// @dart = 2.9
import "dart:collection";
import "package:expect/expect.dart";
import 'cast_helper.dart';
void main() {
void testDowncast() {
var map = new Map.fromIterables(elements, elements);
var dMap = Map.castFrom<C, C, D, D>(map);
Expect.isTrue(dMap is Map<D, D>);
Expect.equals(null, dMap[new C()]);
Expect.throws(() => dMap[c]); // C is not D.
Expect.isTrue(dMap.containsKey(c)); // containsKey should not be typed.
Expect.equals(d, dMap[d]);
Expect.throws(() => dMap[e]); // E is not D.
Expect.equals(null, dMap[null]);
Expect.equals(5, dMap.length);
Expect.throws(() => dMap.remove(c)); // Removes key but fails to return value.
Expect.equals(4, dMap.length);
Expect.equals(null, dMap[c]);
// Runtime errors when assigning or accessing a C.
Expect.throws(() => dMap[c] = d);
Expect.throws(() => dMap[d] = c);
Expect.equals(4, dMap.length);
// Test keys and values.
Expect.isTrue(dMap.keys is Iterable<D>);
Expect.isTrue(dMap.values is Iterable<D>);
Expect.throws(() => dMap.keys.toList());
Expect.throws(() => dMap.values.toList());
void testUpcast() {
var map = new Map.fromIterables(elements, elements);
var objectMap = Map.castFrom<C, C, Object, Object>(map);
Expect.equals(5, objectMap.length);
Expect.equals(c, objectMap[c]);
Expect.equals(c, objectMap.remove(c));
Expect.equals(4, objectMap.length);
// Test keys and values.
Expect.isTrue(objectMap.keys is Iterable<Object>);
Expect.isTrue(objectMap.values is Iterable<Object>);
var expected = new List<Object>.from(elements);
Expect.listEquals(expected, objectMap.keys.toList());
Expect.listEquals(expected, objectMap.values.toList());