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// Copyright (c) 2019, 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.
// SharedOptions=--enable-experiment=variance
// Tests the emission of explicit variance modifiers.
import 'dart:_runtime'
show getGenericArgVariances, Variance, typeRep;
import 'package:expect/expect.dart';
class A<in T> {}
class B<out T> {}
class C<inout T> {}
class D<T> {}
class E<inout X, out Y, in Z> {}
mixin F<in T> {}
class G<inout T> = Object with F<T>;
List? getVariances(Object type) {
// TODO(nshahan) Revisit when we decide if getGenericArgVariances will handle
// legacy and nullable wrappers.
return getGenericArgVariances(type);
main() {
Expect.listEquals([Variance.contravariant], getVariances(typeRep<A>())!);
Expect.listEquals([Variance.covariant], getVariances(typeRep<B>())!);
Expect.listEquals([Variance.invariant], getVariances(typeRep<C>())!);
// Implicit variance is not emitted into the generated code.
[Variance.invariant, Variance.covariant, Variance.contravariant],
Expect.listEquals([Variance.contravariant], getVariances(typeRep<F>())!);
Expect.listEquals([Variance.invariant], getVariances(typeRep<G>())!);