Add TypeMirror.isSubtypeOf, TypeMirror.isAssignableTo, ClassMirror.isSubclassOf

tests/lib/mirrors/relation_subclass_test.dart

+// Copyright (c) 2014, 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.
+
+library test.relation_subclass;
+
+import "dart:mirrors";
+
+import "package:expect/expect.dart";
+
+class Superclass {}
+class Subclass1 extends Superclass {}
+class Subclass2 extends Superclass {}
+
+typedef bool NumberPredicate(num x);
+typedef bool IntegerPredicate(int x);
+typedef bool DoublePredicate(double x);
+
+typedef num NumberGenerator();
+typedef int IntegerGenerator();
+typedef double DoubleGenerator();
+
+test(MirrorSystem mirrors) {
+  LibraryMirror coreLibrary = mirrors.findLibrary(#dart.core);
+  LibraryMirror thisLibrary = mirrors.findLibrary(#test.relation_subclass);
+
+  ClassMirror Super = thisLibrary.declarations[#Superclass];
+  ClassMirror Sub1 = thisLibrary.declarations[#Subclass1];
+  ClassMirror Sub2 = thisLibrary.declarations[#Subclass2];
+  ClassMirror Obj = coreLibrary.declarations[#Object];
+
+  Expect.isTrue(Obj.isSubclassOf(Obj));
+  Expect.isTrue(Super.isSubclassOf(Super));
+  Expect.isTrue(Sub1.isSubclassOf(Sub1));
+  Expect.isTrue(Sub2.isSubclassOf(Sub2));
+
+  Expect.isTrue(Sub1.isSubclassOf(Super));
+  Expect.isFalse(Super.isSubclassOf(Sub1));
+
+  Expect.isTrue(Sub2.isSubclassOf(Super));
+  Expect.isFalse(Super.isSubclassOf(Sub2));
+
+  Expect.isFalse(Sub2.isSubclassOf(Sub1));
+  Expect.isFalse(Sub1.isSubclassOf(Sub2));
+
+  Expect.isTrue(Sub1.isSubclassOf(Obj));
+  Expect.isFalse(Obj.isSubclassOf(Sub1));
+
+  Expect.isTrue(Sub2.isSubclassOf(Obj));
+  Expect.isFalse(Obj.isSubclassOf(Sub2));
+
+  Expect.isTrue(Super.isSubclassOf(Obj));
+  Expect.isFalse(Obj.isSubclassOf(Super));
+
+  var Func = coreLibrary.declarations[#Function];
+  Expect.isTrue(Func.isSubclassOf(Obj));
+  Expect.isFalse(Obj.isSubclassOf(Func));
+
+  // Function typedef.
+  var NumPred = thisLibrary.declarations[#NumberPredicate];
+  var IntPred = thisLibrary.declarations[#IntegerPredicate];
+  var DubPred = thisLibrary.declarations[#DoublePredicate];
+  var NumGen = thisLibrary.declarations[#NumberGenerator];
+  var IntGen = thisLibrary.declarations[#IntegerGenerator];
+  var DubGen = thisLibrary.declarations[#DoubleGenerator];
+
+  isArgumentOrTypeError(e) => e is ArgumentError || e is TypeError;
+  Expect.throws(() => Func.isSubclassOf(NumPred), isArgumentOrTypeError);
+  Expect.throws(() => Func.isSubclassOf(IntPred), isArgumentOrTypeError);
+  Expect.throws(() => Func.isSubclassOf(DubPred), isArgumentOrTypeError);
+  Expect.throws(() => Func.isSubclassOf(NumGen), isArgumentOrTypeError);
+  Expect.throws(() => Func.isSubclassOf(IntGen), isArgumentOrTypeError);
+  Expect.throws(() => Func.isSubclassOf(DubGen), isArgumentOrTypeError);
+
+  isNoSuchMethodError(e) => e is NoSuchMethodError;
+  Expect.throws(() => NumPred.isSubclassOf(Func), isNoSuchMethodError);
+  Expect.throws(() => IntPred.isSubclassOf(Func), isNoSuchMethodError);
+  Expect.throws(() => DubPred.isSubclassOf(Func), isNoSuchMethodError);
+  Expect.throws(() => NumGen.isSubclassOf(Func), isNoSuchMethodError);
+  Expect.throws(() => IntGen.isSubclassOf(Func), isNoSuchMethodError);
+  Expect.throws(() => DubGen.isSubclassOf(Func), isNoSuchMethodError);
+
+  // Function type.
+  TypeMirror NumPredRef = (NumPred as TypedefMirror).referent;
+  TypeMirror IntPredRef = (IntPred as TypedefMirror).referent;
+  TypeMirror DubPredRef = (DubPred as TypedefMirror).referent;
+  TypeMirror NumGenRef = (NumGen as TypedefMirror).referent;
+  TypeMirror IntGenRef = (IntGen as TypedefMirror).referent;
+  TypeMirror DubGenRef = (DubGen as TypedefMirror).referent;
+
+  Expect.isFalse(Func.isSubclassOf(NumPredRef));
+  Expect.isFalse(Func.isSubclassOf(IntPredRef));
+  Expect.isFalse(Func.isSubclassOf(DubPredRef));
+  Expect.isFalse(Func.isSubclassOf(NumGenRef));
+  Expect.isFalse(Func.isSubclassOf(IntGenRef));
+  Expect.isFalse(Func.isSubclassOf(DubGenRef));
+
+  // The spec doesn't require these to be either value, only that they implement
+  // Function.
+  // NumPredRef.isSubclassOf(Func);
+  // IntPredRef.isSubclassOf(Func);
+  // DubPredRef.isSubclassOf(Func);
+  // NumGenRef.isSubclassOf(Func);
+  // IntGenRef.isSubclassOf(Func);
+  // DubGenRef.isSubclassOf(Func);
+}
+
+main() {
+  test(currentMirrorSystem());
+}