// 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.

/*@testedFeatures=inference*/
library test;

class Index {}

class A {
  C operator +(F v) => throw '';
  C operator -(int i) => throw '';
}

class B extends A {
  D operator +(E v) => throw '';
  D operator -(int i) => throw '';
}

class C extends B {}

class D extends C {}

class E extends D {}

class F extends E {}

T f<T>() => throw '';

class Test {
  B operator [](Index i) => throw '';
  void operator []=(Index i, A v) {}

  void test() {
    Test t = /*@typeArgs=Test*/ f();

    t /*@target=Test.[]=*/ [/*@typeArgs=Index*/ f()] = /*@typeArgs=A*/ f();

    t /*@target=Test.[]*/ /*@target=Test.[]=*/ [
        /*@typeArgs=Index*/ f()] /*@target=B.+*/ += /*@typeArgs=E*/ f();

    /*@target=B.-*/ --t /*@target=Test.[]*/ /*@target=Test.[]=*/ [
        /*@typeArgs=Index*/ f()];

    t /*@target=Test.[]*/ /*@target=Test.[]=*/ [
        /*@typeArgs=Index*/ f()] /*@target=B.-*/ --;

    var /*@type=A*/ v1 =
        t /*@target=Test.[]=*/ [/*@typeArgs=Index*/ f()] = /*@typeArgs=A*/ f();

    var /*@type=D*/ v3 = t /*@target=Test.[]*/ /*@target=Test.[]=*/ [
        /*@typeArgs=Index*/ f()] /*@target=B.+*/ += /*@typeArgs=E*/ f();

    var /*@type=D*/ v4 =
        /*@target=B.-*/ --t /*@target=Test.[]*/ /*@target=Test.[]=*/ [
            /*@typeArgs=Index*/ f()];

    var /*@type=B*/ v5 = t /*@target=Test.[]*/ /*@target=Test.[]=*/ [
        /*@typeArgs=Index*/ f()] /*@target=B.-*/ --;
  }
}

class Test2 {
  B? operator [](Index i) => throw '';
  void operator []=(Index i, A? v) {}

  void test() {
    Test2 t = /*@typeArgs=Test2*/ f();

    t /*@target=Test2.[]*/ /*@target=Test2.[]=*/ [
        /*@typeArgs=Index*/ f()] ??= /*@typeArgs=A?*/ f();

    var /*@type=A?*/ v2 = t /*@target=Test2.[]*/ /*@target=Test2.[]=*/ [
        /*@typeArgs=Index*/ f()] ??= /*@typeArgs=A?*/ f();
  }
}

main() {}