Reify implicit casts for FutureOr

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 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import 'strong_test_helper.dart';
 
@@ skipping 903 matching lines @@
 
   test_functionModifiers_async() async {
     await checkFile('''
 import 'dart:async';
 import 'dart:math' show Random;
 
 dynamic x;
 
 foo1() async => x;
 Future foo2() async => x;
-Future<int> foo3() async => x;
+Future<int> foo3() async => /*info:DYNAMIC_CAST*/x;
 Future<int> foo4() async => new Future<int>.value(x);
 Future<int> foo5() async =>
     /*error:RETURN_OF_INVALID_TYPE*/new Future<String>.value(x);
 
 bar1() async { return x; }
 Future bar2() async { return x; }
-Future<int> bar3() async { return x; }
+Future<int> bar3() async { return /*info:DYNAMIC_CAST*/x; }
 Future<int> bar4() async { return new Future<int>.value(x); }
 Future<int> bar5() async {
   return /*error:RETURN_OF_INVALID_TYPE*/new Future<String>.value(x);
 }
 
 int y;
 Future<int> z;
 
 baz() async {
   int a = /*info:DYNAMIC_CAST*/await x;
   int b = await y;
   int c = await z;
   String d = /*error:INVALID_ASSIGNMENT*/await z;
 }
 
 Future<bool> get issue_ddc_264 async {
   await 42;
   if (new Random().nextBool()) {
     return true;
   } else {
     return new Future<bool>.value(false);
   }
 }
 
 
 Future<String> issue_sdk_26404() async {
-  return (1 > 0) ? new Future<String>.value('hello') : "world";
+  return (/*info:DOWN_CAST_COMPOSITE*/(1 > 0) ? new Future<String>.value('hello') : "world");
 }
 ''');
   }
 
   test_functionModifiers_asyncStar() async {
     await checkFile('''
 import 'dart:async';
 
 dynamic x;
 
@@ skipping 1221 matching lines @@
   for (;/*info:DYNAMIC_CAST*/dyn;) {}
   for (;/*info:DOWN_CAST_IMPLICIT*/obj;) {}
   for (;/*error:NON_BOOL_CONDITION*/i;) {}
 }
 ''');
   }
 
   test_implicitCasts() async {
     addFile('num n; int i = /*info:ASSIGNMENT_CAST*/n;');
     await check();
-    // TODO(jmesserly): should not be emitting the hint as well as the error.
-    // It is a "strong mode hint" however, so it will not be user visible.
-    addFile(
-        'num n; int i = /*info:ASSIGNMENT_CAST,error:INVALID_ASSIGNMENT*/n;');
+    addFile('num n; int i = /*error:INVALID_ASSIGNMENT*/n;');
     await check(implicitCasts: false);
   }
 
+  test_implicitCasts_return() async {
+    addFile(r'''
+import 'dart:async';
+
+Future<List<String>> foo() async {
+  List<Object> x = <Object>["hello", "world"];
+  return /*info:DOWN_CAST_IMPLICIT*/x;
+}
+    ''');
+    await check();
+  }
+
   test_implicitCasts_genericMethods() async {
     addFile('''
 var x = <String>[].map<String>((x) => "");
 ''');
     await check(implicitCasts: false);
   }
 
   test_implicitCasts_numericOps() async {
     // Regression test for https://github.com/dart-lang/sdk/issues/26912
     addFile(r'''
@@ skipping 1925 matching lines @@
 class CheckerTest_Driver extends CheckerTest {
   @override
   bool get enableNewAnalysisDriver => true;
 
   @failingTest
   @override
   test_covariantOverride_fields() async {
     await super.test_covariantOverride_fields();
   }
 }