blob: 3ff16d761c4a798e371e8364bc3abff763828c79 [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.
import 'dart:math';
import 'package:expect/expect.dart';
void testInstantiateToBounds() {
f<T extends num, U extends T>() => [T, U];
g<T extends List<U>, U extends int>() => [T, U];
h<T extends num, U extends T>(T x, U y) => h.runtimeType.toString();
Expect.listEquals([num, num], (f as dynamic)());
Expect.equals('List<int>|int', (g as dynamic)().join('|'));
Expect.equals('<T extends num, U extends T>(T, U) => String',
(h as dynamic)(null, null));
i<T extends Iterable<T>>() => null;
j<T extends Iterable<S>, S extends T>() => null;
() => (i as dynamic)(), (e) => '$e'.contains('Instantiate to bounds'));
() => (j as dynamic)(), (e) => '$e'.contains('Instantiate to bounds'));
void testChecksBound() {
f<T extends num>(T x) => x;
Expect.equals((f as dynamic)(42), 42);
Expect.throws(() => (f as dynamic)('42'));
msg(t1, t2, tf) => Expect.throws(() => (f as dynamic)<Object>(42),
(e) => '$e' == 'type `Object` does not extend `num` of `T');
g<T extends U, U extends num>(T x, U y) => x;
Expect.equals((g as dynamic)(42.0, 100), 42.0);
Expect.throws(() => (g as dynamic)('hi', 100));
Expect.throws(() => (g as dynamic)<double, int>(42.0, 100),
(e) => '$e' == 'type `double` does not extend `int` of `T`.');
Expect.throws(() => (g as dynamic)<num, Object>(42.0, 100),
(e) => '$e' == 'type `Object` does not extend `num` of `U`.');
typedef G<U> = T Function<T extends U>(T x);
void testSubtype() {
f<T extends num>(T x) => x + 2;
dynamic d = f;
Expect.equals(d(40.0), 42.0);
Expect.equals((f as G<int>)(40), 42);
Expect.equals((d as G<int>)(40), 42);
Expect.equals((f as G<double>)(40.0), 42.0);
Expect.equals((d as G<double>)(40.0), 42.0);
d as G<Null>;
Expect.throws(() => d as G);
Expect.throws(() => d as G<Object>);
Expect.throws(() => d as G<String>);
void testToString() {
// TODO(jmesserly): I don't think the cast on `y` should be required.
num f<T extends num, U extends T>(T x, U y) => min(x, y as num);
num g<T, U>(T x, U y) => max(x as num, y as num);
String h<T, U>(T x, U y) => h.runtimeType.toString();
f.runtimeType.toString(), '<T extends num, U extends T>(T, U) => num');
Expect.equals(g.runtimeType.toString(), '<T, U>(T, U) => num');
Expect.equals(h(42, 123.0), '<T, U>(T, U) => String');
main() {