// 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.

library subtype_test;

import 'package:expect/expect.dart';
import "package:async_helper/async_helper.dart";
import 'type_test_helper.dart';
import 'package:compiler/src/elements/resolution_types.dart';
import "package:compiler/src/elements/elements.dart" show ClassElement;

void main() {
  testInterfaceSubtype();
  testCallableSubtype();
  testFunctionSubtyping();
  testTypedefSubtyping();
  testFunctionSubtypingOptional();
  testTypedefSubtypingOptional();
  testFunctionSubtypingNamed();
  testTypedefSubtypingNamed();
  testTypeVariableSubtype();
}

void testTypes(TypeEnvironment env, ResolutionDartType subtype,
    ResolutionDartType supertype, bool expectSubtype, bool expectMoreSpecific) {
  if (expectMoreSpecific == null) expectMoreSpecific = expectSubtype;
  Expect.equals(expectSubtype, env.isSubtype(subtype, supertype),
      '$subtype <: $supertype');
  Expect.equals(expectMoreSpecific, env.isMoreSpecific(subtype, supertype),
      '$subtype << $supertype');
}

void testElementTypes(TypeEnvironment env, String subname, String supername,
    bool expectSubtype, bool expectMoreSpecific) {
  ResolutionDartType subtype = env.getElementType(subname);
  ResolutionDartType supertype = env.getElementType(supername);
  testTypes(env, subtype, supertype, expectSubtype, expectMoreSpecific);
}

void testInterfaceSubtype() {
  asyncTest(() => TypeEnvironment.create(r"""
      class A<T> {}
      class B<T1, T2> extends A<T1> {}
      // TODO(johnniwinther): Inheritance with different type arguments is
      // currently not supported by the implementation.
      class C<T1, T2> extends B<T2, T1> /*implements A<A<T1>>*/ {}
      """).then((env) {
        void expect(
            bool expectSubtype, ResolutionDartType T, ResolutionDartType S,
            {bool expectMoreSpecific}) {
          testTypes(env, T, S, expectSubtype, expectMoreSpecific);
        }

        ClassElement A = env.getElement('A');
        ClassElement B = env.getElement('B');
        ClassElement C = env.getElement('C');
        ResolutionDartType Object_ = env['Object'];
        ResolutionDartType num_ = env['num'];
        ResolutionDartType int_ = env['int'];
        ResolutionDartType String_ = env['String'];
        ResolutionDartType dynamic_ = env['dynamic'];
        ResolutionDartType void_ = env['void'];
        ResolutionDartType Null_ = env['Null'];

        expect(true, void_, void_);
        expect(true, void_, dynamic_);
        // Unsure about the next one, see dartbug.com/14933.
        expect(true, dynamic_, void_, expectMoreSpecific: false);
        expect(false, void_, Object_);
        expect(false, Object_, void_);
        expect(true, Null_, void_);

        expect(true, Object_, Object_);
        expect(true, num_, Object_);
        expect(true, int_, Object_);
        expect(true, String_, Object_);
        expect(true, dynamic_, Object_, expectMoreSpecific: false);
        expect(true, Null_, Object_);

        expect(false, Object_, num_);
        expect(true, num_, num_);
        expect(true, int_, num_);
        expect(false, String_, num_);
        expect(true, dynamic_, num_, expectMoreSpecific: false);
        expect(true, Null_, num_);

        expect(false, Object_, int_);
        expect(false, num_, int_);
        expect(true, int_, int_);
        expect(false, String_, int_);
        expect(true, dynamic_, int_, expectMoreSpecific: false);
        expect(true, Null_, int_);

        expect(false, Object_, String_);
        expect(false, num_, String_);
        expect(false, int_, String_);
        expect(true, String_, String_);
        expect(true, dynamic_, String_, expectMoreSpecific: false);
        expect(true, Null_, String_);

        expect(true, Object_, dynamic_);
        expect(true, num_, dynamic_);
        expect(true, int_, dynamic_);
        expect(true, String_, dynamic_);
        expect(true, dynamic_, dynamic_);
        expect(true, Null_, dynamic_);

        expect(false, Object_, Null_);
        expect(false, num_, Null_);
        expect(false, int_, Null_);
        expect(false, String_, Null_);
        expect(true, dynamic_, Null_, expectMoreSpecific: false);
        expect(true, Null_, Null_);

        ResolutionDartType A_Object = instantiate(A, [Object_]);
        ResolutionDartType A_num = instantiate(A, [num_]);
        ResolutionDartType A_int = instantiate(A, [int_]);
        ResolutionDartType A_String = instantiate(A, [String_]);
        ResolutionDartType A_dynamic = instantiate(A, [dynamic_]);
        ResolutionDartType A_Null = instantiate(A, [Null_]);

        expect(true, A_Object, Object_);
        expect(false, A_Object, num_);
        expect(false, A_Object, int_);
        expect(false, A_Object, String_);
        expect(true, A_Object, dynamic_);
        expect(false, A_Object, Null_);

        expect(true, A_Object, A_Object);
        expect(true, A_num, A_Object);
        expect(true, A_int, A_Object);
        expect(true, A_String, A_Object);
        expect(true, A_dynamic, A_Object, expectMoreSpecific: false);
        expect(true, A_Null, A_Object);

        expect(false, A_Object, A_num);
        expect(true, A_num, A_num);
        expect(true, A_int, A_num);
        expect(false, A_String, A_num);
        expect(true, A_dynamic, A_num, expectMoreSpecific: false);
        expect(true, A_Null, A_num);

        expect(false, A_Object, A_int);
        expect(false, A_num, A_int);
        expect(true, A_int, A_int);
        expect(false, A_String, A_int);
        expect(true, A_dynamic, A_int, expectMoreSpecific: false);
        expect(true, A_Null, A_int);

        expect(false, A_Object, A_String);
        expect(false, A_num, A_String);
        expect(false, A_int, A_String);
        expect(true, A_String, A_String);
        expect(true, A_dynamic, A_String, expectMoreSpecific: false);
        expect(true, A_Null, A_String);

        expect(true, A_Object, A_dynamic);
        expect(true, A_num, A_dynamic);
        expect(true, A_int, A_dynamic);
        expect(true, A_String, A_dynamic);
        expect(true, A_dynamic, A_dynamic);
        expect(true, A_Null, A_dynamic);

        expect(false, A_Object, A_Null);
        expect(false, A_num, A_Null);
        expect(false, A_int, A_Null);
        expect(false, A_String, A_Null);
        expect(true, A_dynamic, A_Null, expectMoreSpecific: false);
        expect(true, A_Null, A_Null);

        ResolutionDartType B_Object_Object = instantiate(B, [Object_, Object_]);
        ResolutionDartType B_num_num = instantiate(B, [num_, num_]);
        ResolutionDartType B_int_num = instantiate(B, [int_, num_]);
        ResolutionDartType B_dynamic_dynamic =
            instantiate(B, [dynamic_, dynamic_]);
        ResolutionDartType B_String_dynamic =
            instantiate(B, [String_, dynamic_]);

        expect(true, B_Object_Object, Object_);
        expect(true, B_Object_Object, A_Object);
        expect(false, B_Object_Object, A_num);
        expect(false, B_Object_Object, A_int);
        expect(false, B_Object_Object, A_String);
        expect(true, B_Object_Object, A_dynamic);

        expect(true, B_num_num, Object_);
        expect(true, B_num_num, A_Object);
        expect(true, B_num_num, A_num);
        expect(false, B_num_num, A_int);
        expect(false, B_num_num, A_String);
        expect(true, B_num_num, A_dynamic);

        expect(true, B_int_num, Object_);
        expect(true, B_int_num, A_Object);
        expect(true, B_int_num, A_num);
        expect(true, B_int_num, A_int);
        expect(false, B_int_num, A_String);
        expect(true, B_int_num, A_dynamic);

        expect(true, B_dynamic_dynamic, Object_);
        expect(true, B_dynamic_dynamic, A_Object, expectMoreSpecific: false);
        expect(true, B_dynamic_dynamic, A_num, expectMoreSpecific: false);
        expect(true, B_dynamic_dynamic, A_int, expectMoreSpecific: false);
        expect(true, B_dynamic_dynamic, A_String, expectMoreSpecific: false);
        expect(true, B_dynamic_dynamic, A_dynamic);

        expect(true, B_String_dynamic, Object_);
        expect(true, B_String_dynamic, A_Object);
        expect(false, B_String_dynamic, A_num);
        expect(false, B_String_dynamic, A_int);
        expect(true, B_String_dynamic, A_String);
        expect(true, B_String_dynamic, A_dynamic);

        expect(true, B_Object_Object, B_Object_Object);
        expect(true, B_num_num, B_Object_Object);
        expect(true, B_int_num, B_Object_Object);
        expect(true, B_dynamic_dynamic, B_Object_Object,
            expectMoreSpecific: false);
        expect(true, B_String_dynamic, B_Object_Object,
            expectMoreSpecific: false);

        expect(false, B_Object_Object, B_num_num);
        expect(true, B_num_num, B_num_num);
        expect(true, B_int_num, B_num_num);
        expect(true, B_dynamic_dynamic, B_num_num, expectMoreSpecific: false);
        expect(false, B_String_dynamic, B_num_num);

        expect(false, B_Object_Object, B_int_num);
        expect(false, B_num_num, B_int_num);
        expect(true, B_int_num, B_int_num);
        expect(true, B_dynamic_dynamic, B_int_num, expectMoreSpecific: false);
        expect(false, B_String_dynamic, B_int_num);

        expect(true, B_Object_Object, B_dynamic_dynamic);
        expect(true, B_num_num, B_dynamic_dynamic);
        expect(true, B_int_num, B_dynamic_dynamic);
        expect(true, B_dynamic_dynamic, B_dynamic_dynamic);
        expect(true, B_String_dynamic, B_dynamic_dynamic);

        expect(false, B_Object_Object, B_String_dynamic);
        expect(false, B_num_num, B_String_dynamic);
        expect(false, B_int_num, B_String_dynamic);
        expect(true, B_dynamic_dynamic, B_String_dynamic,
            expectMoreSpecific: false);
        expect(true, B_String_dynamic, B_String_dynamic);

        ResolutionDartType C_Object_Object = instantiate(C, [Object_, Object_]);
        ResolutionDartType C_num_num = instantiate(C, [num_, num_]);
        ResolutionDartType C_int_String = instantiate(C, [int_, String_]);
        ResolutionDartType C_dynamic_dynamic =
            instantiate(C, [dynamic_, dynamic_]);

        expect(true, C_Object_Object, B_Object_Object);
        expect(false, C_Object_Object, B_num_num);
        expect(false, C_Object_Object, B_int_num);
        expect(true, C_Object_Object, B_dynamic_dynamic);
        expect(false, C_Object_Object, B_String_dynamic);

        expect(true, C_num_num, B_Object_Object);
        expect(true, C_num_num, B_num_num);
        expect(false, C_num_num, B_int_num);
        expect(true, C_num_num, B_dynamic_dynamic);
        expect(false, C_num_num, B_String_dynamic);

        expect(true, C_int_String, B_Object_Object);
        expect(false, C_int_String, B_num_num);
        expect(false, C_int_String, B_int_num);
        expect(true, C_int_String, B_dynamic_dynamic);
        expect(true, C_int_String, B_String_dynamic);

        expect(true, C_dynamic_dynamic, B_Object_Object,
            expectMoreSpecific: false);
        expect(true, C_dynamic_dynamic, B_num_num, expectMoreSpecific: false);
        expect(true, C_dynamic_dynamic, B_int_num, expectMoreSpecific: false);
        expect(true, C_dynamic_dynamic, B_dynamic_dynamic);
        expect(true, C_dynamic_dynamic, B_String_dynamic,
            expectMoreSpecific: false);

        expect(false, C_int_String, A_int);
        expect(true, C_int_String, A_String);
        // TODO(johnniwinther): Inheritance with different type arguments is
        // currently not supported by the implementation.
        //expect(true, C_int_String, instantiate(A, [A_int]));
        expect(false, C_int_String, instantiate(A, [A_String]));
      }));
}

void testCallableSubtype() {
  asyncTest(() => TypeEnvironment.create(r"""
      class U {}
      class V extends U {}
      class W extends V {}
      class A {
        int call(V v, int i);

        int m1(U u, int i);
        int m2(W w, num n);
        U m3(V v, int i);
        int m4(V v, U u);
        void m5(V v, int i);
      }
      """).then((env) {
        void expect(
            bool expectSubtype, ResolutionDartType T, ResolutionDartType S,
            {bool expectMoreSpecific}) {
          testTypes(env, T, S, expectSubtype, expectMoreSpecific);
        }

        ClassElement classA = env.getElement('A');
        ResolutionDartType A = classA.rawType;
        ResolutionDartType function = env['Function'];
        ResolutionDartType call = env.getMemberType(classA, 'call');
        ResolutionDartType m1 = env.getMemberType(classA, 'm1');
        ResolutionDartType m2 = env.getMemberType(classA, 'm2');
        ResolutionDartType m3 = env.getMemberType(classA, 'm3');
        ResolutionDartType m4 = env.getMemberType(classA, 'm4');
        ResolutionDartType m5 = env.getMemberType(classA, 'm5');

        expect(true, A, function);
        expect(true, A, call);
        expect(true, call, m1);
        expect(true, A, m1);
        expect(true, A, m2, expectMoreSpecific: false);
        expect(false, A, m3);
        expect(false, A, m4);
        expect(true, A, m5);
      }));
}

testFunctionSubtyping() {
  asyncTest(() => TypeEnvironment.create(r"""
      _() => null;
      void void_() {}
      void void_2() {}
      int int_() => 0;
      int int_2() => 0;
      Object Object_() => null;
      double double_() => 0.0;
      void void__int(int i) {}
      int int__int(int i) => 0;
      int int__int2(int i) => 0;
      int int__Object(Object o) => 0;
      Object Object__int(int i) => null;
      int int__double(double d) => 0;
      int int__int_int(int i1, int i2) => 0;
      void inline_void_(void f()) {}
      void inline_void__int(void f(int i)) {}
      """).then(functionSubtypingHelper));
}

testTypedefSubtyping() {
  asyncTest(() => TypeEnvironment.create(r"""
      typedef _();
      typedef void void_();
      typedef void void_2();
      typedef int int_();
      typedef int int_2();
      typedef Object Object_();
      typedef double double_();
      typedef void void__int(int i);
      typedef int int__int(int i);
      typedef int int__int2(int i);
      typedef int int__Object(Object o);
      typedef Object Object__int(int i);
      typedef int int__double(double d);
      typedef int int__int_int(int i1, int i2);
      typedef void inline_void_(void f());
      typedef void inline_void__int(void f(int i));
      """).then(functionSubtypingHelper));
}

functionSubtypingHelper(TypeEnvironment env) {
  void expect(bool expectSubtype, String sub, String sup,
      {bool expectMoreSpecific}) {
    testElementTypes(env, sub, sup, expectSubtype, expectMoreSpecific);
  }

  // () -> int <: Function
  expect(true, 'int_', 'Function');
  // Function <: () -> int
  expect(false, 'Function', 'int_');

  // () -> dynamic <: () -> dynamic
  expect(true, '_', '_');
  // () -> dynamic <: () -> void
  expect(true, '_', 'void_');
  // () -> void <: () -> dynamic
  expect(true, 'void_', '_', expectMoreSpecific: false);

  // () -> int <: () -> void
  expect(true, 'int_', 'void_');
  // () -> void <: () -> int
  expect(false, 'void_', 'int_');
  // () -> void <: () -> void
  expect(true, 'void_', 'void_2');
  // () -> int <: () -> int
  expect(true, 'int_', 'int_2');
  // () -> int <: () -> Object
  expect(true, 'int_', 'Object_');
  // () -> int <: () -> double
  expect(false, 'int_', 'double_');
  // () -> int <: (int) -> void
  expect(false, 'int_', 'void__int');
  // () -> void <: (int) -> int
  expect(false, 'void_', 'int__int');
  // () -> void <: (int) -> void
  expect(false, 'void_', 'void__int');
  // (int) -> int <: (int) -> int
  expect(true, 'int__int', 'int__int2');
  // (Object) -> int <: (int) -> Object
  expect(true, 'int__Object', 'Object__int', expectMoreSpecific: false);
  // (int) -> int <: (double) -> int
  expect(false, 'int__int', 'int__double');
  // () -> int <: (int) -> int
  expect(false, 'int_', 'int__int');
  // (int) -> int <: (int,int) -> int
  expect(false, 'int__int', 'int__int_int');
  // (int,int) -> int <: (int) -> int
  expect(false, 'int__int_int', 'int__int');
  // (()->void) -> void <: ((int)->void) -> void
  expect(false, 'inline_void_', 'inline_void__int');
  // ((int)->void) -> void <: (()->void) -> void
  expect(false, 'inline_void__int', 'inline_void_');
}

testFunctionSubtypingOptional() {
  asyncTest(() => TypeEnvironment.create(r"""
      void void_() {}
      void void__int(int i) {}
      void void___int([int i]) {}
      void void___int2([int i]) {}
      void void___Object([Object o]) {}
      void void__int__int(int i1, [int i2]) {}
      void void__int__int2(int i1, [int i2]) {}
      void void__int__int_int(int i1, [int i2, int i3]);
      void void___double(double d) {}
      void void___int_int([int i1, int i2]) {}
      void void___int_int_int([int i1, int i2, int i3]);
      void void___Object_int([Object o, int i]) {}
      """).then(functionSubtypingOptionalHelper));
}

testTypedefSubtypingOptional() {
  asyncTest(() => TypeEnvironment.create(r"""
      typedef void void_();
      typedef void void__int(int i);
      typedef void void___int([int i]);
      typedef void void___int2([int i]);
      typedef void void___Object([Object o]);
      typedef void void__int__int(int i1, [int i2]);
      typedef void void__int__int2(int i1, [int i2]);
      typedef void void__int__int_int(int i1, [int i2, int i3]);
      typedef void void___double(double d);
      typedef void void___int_int([int i1, int i2]);
      typedef void void___int_int_int([int i1, int i2, int i3]);
      typedef void void___Object_int([Object o, int i]);
      """).then(functionSubtypingOptionalHelper));
}

functionSubtypingOptionalHelper(TypeEnvironment env) {
  void expect(bool expectSubtype, String sub, String sup,
      {bool expectMoreSpecific}) {
    testElementTypes(env, sub, sup, expectSubtype, expectMoreSpecific);
  }

  // Test ([int])->void <: ()->void.
  expect(true, 'void___int', 'void_');
  // Test ([int])->void <: (int)->void.
  expect(true, 'void___int', 'void__int');
  // Test (int)->void <: ([int])->void.
  expect(false, 'void__int', 'void___int');
  // Test ([int])->void <: ([int])->void.
  expect(true, 'void___int', 'void___int2');
  // Test ([Object])->void <: ([int])->void.
  expect(true, 'void___Object', 'void___int', expectMoreSpecific: false);
  // Test ([int])->void <: ([Object])->void.
  expect(true, 'void___int', 'void___Object');
  // Test (int,[int])->void <: (int)->void.
  expect(true, 'void__int__int', 'void__int');
  // Test (int,[int])->void <: (int,[int])->void.
  expect(true, 'void__int__int', 'void__int__int2');
  // Test (int)->void <: ([int])->void.
  expect(false, 'void__int', 'void___int');
  // Test ([int,int])->void <: (int)->void.
  expect(true, 'void___int_int', 'void__int');
  // Test ([int,int])->void <: (int,[int])->void.
  expect(true, 'void___int_int', 'void__int__int');
  // Test ([int,int])->void <: (int,[int,int])->void.
  expect(false, 'void___int_int', 'void__int__int_int');
  // Test ([int,int,int])->void <: (int,[int,int])->void.
  expect(true, 'void___int_int_int', 'void__int__int_int');
  // Test ([int])->void <: ([double])->void.
  expect(false, 'void___int', 'void___double');
  // Test ([int])->void <: ([int,int])->void.
  expect(false, 'void___int', 'void___int_int');
  // Test ([int,int])->void <: ([int])->void.
  expect(true, 'void___int_int', 'void___int');
  // Test ([Object,int])->void <: ([int])->void.
  expect(true, 'void___Object_int', 'void___int', expectMoreSpecific: false);
}

testFunctionSubtypingNamed() {
  asyncTest(() => TypeEnvironment.create(r"""
      void void_() {}
      void void__int(int i) {}
      void void___a_int({int a}) {}
      void void___a_int2({int a}) {}
      void void___b_int({int b}) {}
      void void___a_Object({Object a}) {}
      void void__int__a_int(int i1, {int a}) {}
      void void__int__a_int2(int i1, {int a}) {}
      void void___a_double({double a}) {}
      void void___a_int_b_int({int a, int b}) {}
      void void___a_int_b_int_c_int({int a, int b, int c}) {}
      void void___a_int_c_int({int a, int c}) {}
      void void___b_int_c_int({int b, int c}) {}
      void void___c_int({int c}) {}
      """).then(functionSubtypingNamedHelper));
}

testTypedefSubtypingNamed() {
  asyncTest(() => TypeEnvironment.create(r"""
      typedef void void_();
      typedef void void__int(int i);
      typedef void void___a_int({int a});
      typedef void void___a_int2({int a});
      typedef void void___b_int({int b});
      typedef void void___a_Object({Object a});
      typedef void void__int__a_int(int i1, {int a});
      typedef void void__int__a_int2(int i1, {int a});
      typedef void void___a_double({double a});
      typedef void void___a_int_b_int({int a, int b});
      typedef void void___a_int_b_int_c_int({int a, int b, int c});
      typedef void void___a_int_c_int({int a, int c});
      typedef void void___b_int_c_int({int b, int c});
      typedef void void___c_int({int c});
      """).then(functionSubtypingNamedHelper));
}

functionSubtypingNamedHelper(TypeEnvironment env) {
  expect(bool expectSubtype, String sub, String sup,
      {bool expectMoreSpecific}) {
    testElementTypes(env, sub, sup, expectSubtype, expectMoreSpecific);
  }

  // Test ({int a})->void <: ()->void.
  expect(true, 'void___a_int', 'void_');
  // Test ({int a})->void <: (int)->void.
  expect(false, 'void___a_int', 'void__int');
  // Test (int)->void <: ({int a})->void.
  expect(false, 'void__int', 'void___a_int');
  // Test ({int a})->void <: ({int a})->void.
  expect(true, 'void___a_int', 'void___a_int2');
  // Test ({int a})->void <: ({int b})->void.
  expect(false, 'void___a_int', 'void___b_int');
  // Test ({Object a})->void <: ({int a})->void.
  expect(true, 'void___a_Object', 'void___a_int', expectMoreSpecific: false);
  // Test ({int a})->void <: ({Object a})->void.
  expect(true, 'void___a_int', 'void___a_Object');
  // Test (int,{int a})->void <: (int,{int a})->void.
  expect(true, 'void__int__a_int', 'void__int__a_int2');
  // Test ({int a})->void <: ({double a})->void.
  expect(false, 'void___a_int', 'void___a_double');
  // Test ({int a})->void <: ({int a,int b})->void.
  expect(false, 'void___a_int', 'void___a_int_b_int');
  // Test ({int a,int b})->void <: ({int a})->void.
  expect(true, 'void___a_int_b_int', 'void___a_int');
  // Test ({int a,int b,int c})->void <: ({int a,int c})->void.
  expect(true, 'void___a_int_b_int_c_int', 'void___a_int_c_int');
  // Test ({int a,int b,int c})->void <: ({int b,int c})->void.
  expect(true, 'void___a_int_b_int_c_int', 'void___b_int_c_int');
  // Test ({int a,int b,int c})->void <: ({int c})->void.
  expect(true, 'void___a_int_b_int_c_int', 'void___c_int');
}

void testTypeVariableSubtype() {
  asyncTest(() => TypeEnvironment.create(r"""
      class A<T> {}
      class B<T extends Object> {}
      class C<T extends num> {}
      class D<T extends int> {}
      class E<T extends S, S extends num> {}
      class F<T extends num, S extends T> {}
      class G<T extends T> {}
      class H<T extends S, S extends T> {}
      class I<T extends S, S extends U, U extends T> {}
      class J<T extends S, S extends U, U extends S> {}
      """).then((env) {
        void expect(
            bool expectSubtype, ResolutionDartType T, ResolutionDartType S,
            {bool expectMoreSpecific}) {
          testTypes(env, T, S, expectSubtype, expectMoreSpecific);
        }

        ClassElement A = env.getElement('A');
        ResolutionTypeVariableType A_T = A.thisType.typeArguments[0];
        ClassElement B = env.getElement('B');
        ResolutionTypeVariableType B_T = B.thisType.typeArguments[0];
        ClassElement C = env.getElement('C');
        ResolutionTypeVariableType C_T = C.thisType.typeArguments[0];
        ClassElement D = env.getElement('D');
        ResolutionTypeVariableType D_T = D.thisType.typeArguments[0];
        ClassElement E = env.getElement('E');
        ResolutionTypeVariableType E_T = E.thisType.typeArguments[0];
        ResolutionTypeVariableType E_S = E.thisType.typeArguments[1];
        ClassElement F = env.getElement('F');
        ResolutionTypeVariableType F_T = F.thisType.typeArguments[0];
        ResolutionTypeVariableType F_S = F.thisType.typeArguments[1];
        ClassElement G = env.getElement('G');
        ResolutionTypeVariableType G_T = G.thisType.typeArguments[0];
        ClassElement H = env.getElement('H');
        ResolutionTypeVariableType H_T = H.thisType.typeArguments[0];
        ResolutionTypeVariableType H_S = H.thisType.typeArguments[1];
        ClassElement I = env.getElement('I');
        ResolutionTypeVariableType I_T = I.thisType.typeArguments[0];
        ResolutionTypeVariableType I_S = I.thisType.typeArguments[1];
        ResolutionTypeVariableType I_U = I.thisType.typeArguments[2];
        ClassElement J = env.getElement('J');
        ResolutionTypeVariableType J_T = J.thisType.typeArguments[0];
        ResolutionTypeVariableType J_S = J.thisType.typeArguments[1];
        ResolutionTypeVariableType J_U = J.thisType.typeArguments[2];

        ResolutionDartType Object_ = env['Object'];
        ResolutionDartType num_ = env['num'];
        ResolutionDartType int_ = env['int'];
        ResolutionDartType String_ = env['String'];
        ResolutionDartType dynamic_ = env['dynamic'];

        // class A<T> {}
        expect(true, A_T, Object_);
        expect(false, A_T, num_);
        expect(false, A_T, int_);
        expect(false, A_T, String_);
        expect(true, A_T, dynamic_);
        expect(true, A_T, A_T);
        expect(false, A_T, B_T);

        // class B<T extends Object> {}
        expect(true, B_T, Object_);
        expect(false, B_T, num_);
        expect(false, B_T, int_);
        expect(false, B_T, String_);
        expect(true, B_T, dynamic_);
        expect(true, B_T, B_T);
        expect(false, B_T, A_T);

        // class C<T extends num> {}
        expect(true, C_T, Object_);
        expect(true, C_T, num_);
        expect(false, C_T, int_);
        expect(false, C_T, String_);
        expect(true, C_T, dynamic_);
        expect(true, C_T, C_T);
        expect(false, C_T, A_T);

        // class D<T extends int> {}
        expect(true, D_T, Object_);
        expect(true, D_T, num_);
        expect(true, D_T, int_);
        expect(false, D_T, String_);
        expect(true, D_T, dynamic_);
        expect(true, D_T, D_T);
        expect(false, D_T, A_T);

        // class E<T extends S, S extends num> {}
        expect(true, E_T, Object_);
        expect(true, E_T, num_);
        expect(false, E_T, int_);
        expect(false, E_T, String_);
        expect(true, E_T, dynamic_);
        expect(true, E_T, E_T);
        expect(true, E_T, E_S);
        expect(false, E_T, A_T);

        expect(true, E_S, Object_);
        expect(true, E_S, num_);
        expect(false, E_S, int_);
        expect(false, E_S, String_);
        expect(true, E_S, dynamic_);
        expect(false, E_S, E_T);
        expect(true, E_S, E_S);
        expect(false, E_S, A_T);

        // class F<T extends num, S extends T> {}
        expect(true, F_T, Object_);
        expect(true, F_T, num_);
        expect(false, F_T, int_);
        expect(false, F_T, String_);
        expect(true, F_T, dynamic_);
        expect(false, F_T, F_S);
        expect(true, F_T, F_T);
        expect(false, F_T, A_T);

        expect(true, F_S, Object_);
        expect(true, F_S, num_);
        expect(false, F_S, int_);
        expect(false, F_S, String_);
        expect(true, F_S, dynamic_);
        expect(true, F_S, F_S);
        expect(true, F_S, F_T);
        expect(false, F_S, A_T);

        // class G<T extends T> {}
        expect(true, G_T, Object_);
        expect(false, G_T, num_);
        expect(false, G_T, int_);
        expect(false, G_T, String_);
        expect(true, G_T, dynamic_);
        expect(true, G_T, G_T);
        expect(false, G_T, A_T);

        // class H<T extends S, S extends T> {}
        expect(true, H_T, Object_);
        expect(false, H_T, num_);
        expect(false, H_T, int_);
        expect(false, H_T, String_);
        expect(true, H_T, dynamic_);
        expect(true, H_T, H_T);
        expect(true, H_T, H_S);
        expect(false, H_T, A_T);

        expect(true, H_S, Object_);
        expect(false, H_S, num_);
        expect(false, H_S, int_);
        expect(false, H_S, String_);
        expect(true, H_S, dynamic_);
        expect(true, H_S, H_T);
        expect(true, H_S, H_S);
        expect(false, H_S, A_T);

        // class I<T extends S, S extends U, U extends T> {}
        expect(true, I_T, Object_);
        expect(false, I_T, num_);
        expect(false, I_T, int_);
        expect(false, I_T, String_);
        expect(true, I_T, dynamic_);
        expect(true, I_T, I_T);
        expect(true, I_T, I_S);
        expect(true, I_T, I_U);
        expect(false, I_T, A_T);

        expect(true, I_S, Object_);
        expect(false, I_S, num_);
        expect(false, I_S, int_);
        expect(false, I_S, String_);
        expect(true, I_S, dynamic_);
        expect(true, I_S, I_T);
        expect(true, I_S, I_S);
        expect(true, I_S, I_U);
        expect(false, I_S, A_T);

        expect(true, I_U, Object_);
        expect(false, I_U, num_);
        expect(false, I_U, int_);
        expect(false, I_U, String_);
        expect(true, I_U, dynamic_);
        expect(true, I_U, I_T);
        expect(true, I_U, I_S);
        expect(true, I_U, I_U);
        expect(false, I_U, A_T);

        // class J<T extends S, S extends U, U extends S> {}
        expect(true, J_T, Object_);
        expect(false, J_T, num_);
        expect(false, J_T, int_);
        expect(false, J_T, String_);
        expect(true, J_T, dynamic_);
        expect(true, J_T, J_T);
        expect(true, J_T, J_S);
        expect(true, J_T, J_U);
        expect(false, J_T, A_T);

        expect(true, J_S, Object_);
        expect(false, J_S, num_);
        expect(false, J_S, int_);
        expect(false, J_S, String_);
        expect(true, J_S, dynamic_);
        expect(false, J_S, J_T);
        expect(true, J_S, J_S);
        expect(true, J_S, J_U);
        expect(false, J_S, A_T);

        expect(true, J_U, Object_);
        expect(false, J_U, num_);
        expect(false, J_U, int_);
        expect(false, J_U, String_);
        expect(true, J_U, dynamic_);
        expect(false, J_U, J_T);
        expect(true, J_U, J_S);
        expect(true, J_U, J_U);
        expect(false, J_U, A_T);
      }));
}