tests/lib/mirrors/type_variable_owner_test.dart

// Copyright (c) 2013, 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.

// Owner of a type variable should be the declaration of the generic class or
// typedef, not an instantiation.

library test.type_variable_owner;

import "dart:mirrors";

import "package:expect/expect.dart";

class A<T> {}

class B<R> extends A<R> {}

testTypeVariableOfClass() {
  ClassMirror aDecl = reflectClass(A);
  ClassMirror bDecl = reflectClass(B);
  ClassMirror aOfInt = reflect(new A<int>()).type;
  ClassMirror aOfR = bDecl.superclass!;
  ClassMirror bOfString = reflect(new B<String>()).type;
  ClassMirror aOfString = bOfString.superclass!;

  Expect.equals(aDecl, aDecl.typeVariables[0].owner);
  Expect.equals(aDecl, aOfInt.typeVariables[0].owner);
  Expect.equals(aDecl, aOfR.typeVariables[0].owner);
  Expect.equals(aDecl, aOfString.typeVariables[0].owner);

  Expect.equals(bDecl, bDecl.typeVariables[0].owner);
  Expect.equals(bDecl, bOfString.typeVariables[0].owner);
}

typedef bool Predicate<T>(T t);
late Predicate<List> somePredicateOfList;

testTypeVariableOfTypedef() {
  LibraryMirror thisLibrary =
      currentMirrorSystem().findLibrary(#test.type_variable_owner);

  TypedefMirror predicateOfDynamic = reflectType(Predicate) as TypedefMirror;
  TypedefMirror predicateOfList =
      (thisLibrary.declarations[#somePredicateOfList] as VariableMirror).type as TypedefMirror;
  TypedefMirror predicateDecl = predicateOfList.originalDeclaration as TypedefMirror;

  Expect.equals(predicateDecl, predicateOfDynamic.typeVariables[0].owner);
  Expect.equals(predicateDecl, predicateOfList.typeVariables[0].owner);
  Expect.equals(predicateDecl, predicateDecl.typeVariables[0].owner);
}

main() {
  testTypeVariableOfClass();
  testTypeVariableOfTypedef(); // //# 01: ok
}