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.
+
+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();
+
+main() {
+  ClassMirror Super = reflectType(Superclass);
+  ClassMirror Sub1 = reflectType(Subclass1);
+  ClassMirror Sub2 = reflectType(Subclass2);
+  ClassMirror Obj = reflectType(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));
+
+  return; /// 01: ok
+
+  TypeMirror Func = reflectType(Function);
+  Expect.isTrue(Func.isSubclassOf(Obj));
+  Expect.isFalse(Obj.isSubclassOf(Func));
+
+  // Function typedef.
+  TypeMirror NumPred = reflectType(NumberPredicate);
+  TypeMirror IntPred = reflectType(IntegerPredicate);
+  TypeMirror DubPred = reflectType(DoublePredicate);
+  TypeMirror NumGen = reflectType(NumberGenerator);
+  TypeMirror IntGen = reflectType(IntegerGenerator);
+  TypeMirror DubGen = reflectType(DoubleGenerator);
+
+  Expect.throws(() => Func.isSubclassOf(NumPred), (e) => e is ArgumentError || e is TypeError);
+  Expect.throws(() => Func.isSubclassOf(IntPred), (e) => e is ArgumentError || e is TypeError);
+  Expect.throws(() => Func.isSubclassOf(DubPred), (e) => e is ArgumentError || e is TypeError);
+  Expect.throws(() => Func.isSubclassOf(NumGen), (e) => e is ArgumentError || e is TypeError);
+  Expect.throws(() => Func.isSubclassOf(IntGen), (e) => e is ArgumentError || e is TypeError);
+  Expect.throws(() => Func.isSubclassOf(DubGen), (e) => e is ArgumentError || e is TypeError);
+
+  Expect.throws(() => NumPred.isSubclassOf(Func), (e) => e is NoSuchMethodError);
+  Expect.throws(() => IntPred.isSubclassOf(Func), (e) => e is NoSuchMethodError);
+  Expect.throws(() => DubPred.isSubclassOf(Func), (e) => e is NoSuchMethodError);
+  Expect.throws(() => NumGen.isSubclassOf(Func), (e) => e is NoSuchMethodError);
+  Expect.throws(() => IntGen.isSubclassOf(Func), (e) => e is NoSuchMethodError);
+  Expect.throws(() => DubGen.isSubclassOf(Func), (e) => e is NoSuchMethodError);
+
+  // Function type.
+  TypeMirror NumPredRef = reflectType(NumberPredicate).referent;
+  TypeMirror IntPredRef = reflectType(IntegerPredicate).referent;
+  TypeMirror DubPredRef = reflectType(DoublePredicate).referent;
+  TypeMirror NumGenRef = reflectType(NumberGenerator).referent;
+  TypeMirror IntGenRef = reflectType(IntegerGenerator).referent;
+  TypeMirror DubGenRef = reflectType(DoubleGenerator).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.
+  // NumPredRef.isSubclassOf(Func);
+  // IntPredRef.isSubclassOf(Func);
+  // DubPredRef.isSubclassOf(Func);
+  // NumGenRef.isSubclassOf(Func);
+  // IntGenRef.isSubclassOf(Func);
+  // DubGenRef.isSubclassOf(Func);
+}