fix #26141, add support for type arguments to constants

pkg/analyzer/test/src/task/strong/checker_test.dart

 // Copyright (c) 2015, 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 analyzer.test.src.task.strong.checker_test;
 
 import '../../../reflective_tests.dart';
 import 'strong_test_helper.dart';
 
 void main() {
@@ skipping 2146 matching lines @@
 var /*error:IMPLICIT_DYNAMIC_VARIABLE*/x1 = (<dynamic>[])[0];
 var /*error:IMPLICIT_DYNAMIC_VARIABLE*/x2,
     x3 = 42,
     /*error:IMPLICIT_DYNAMIC_VARIABLE*/x4;
 dynamic y0;
 dynamic y1 = (<dynamic>[])[0];
     ''');
     check(implicitDynamic: false);
   }
 
+  void test_constantGenericTypeArg_infer() {
+    // Regression test for https://github.com/dart-lang/sdk/issues/26141
+    checkFile('''
+abstract class Equality<R> {}
+class DefaultEquality<S> implements Equality<S> {
+  const DefaultEquality();
+}
+class SetEquality<T> implements Equality<T> {
+  final Equality<T> field = const DefaultEquality();
+  const SetEquality([Equality<T> inner = const DefaultEquality()]);
+}
+main() {
+  const SetEquality<String>();
+}
+    ''');
+  }
+
+  void test_constantGenericTypeArg_explict() {
+    // Regression test for https://github.com/dart-lang/sdk/issues/26141
+    checkFile('''
+abstract class Equality<R> {}
+class DefaultEquality<S> implements Equality<S> {
+  const DefaultEquality();
+}
+class SetEquality<T> implements Equality<T> {
+  final Equality<T> field = const DefaultEquality<T>();
+  const SetEquality([Equality<T> inner = const DefaultEquality<T>()]);
+}
+main() {
+  const SetEquality<String>();
+}
+    ''');
+  }
+
   void test_invalidOverrides_baseClassOverrideToChildInterface() {
     checkFile('''
 class A {}
 class B {}
 
 abstract class I {
     m(A a);
 }
 
 class Base {
@@ skipping 1380 matching lines @@
     // Regression test for https://github.com/dart-lang/sdk/issues/25069
     checkFile('''
 typedef int Foo();
 void foo() {}
 void main () {
   Foo x = /*error:INVALID_ASSIGNMENT,info:USE_OF_VOID_RESULT*/foo();
 }
 ''');
   }
 }