Fix summary type inference for async closures.

pkg/analyzer/test/src/task/strong/inferred_type_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.
 
 // TODO(jmesserly): this file needs to be refactored, it's a port from
 // package:dev_compiler's tests
 /// Tests for type inference.
 library analyzer.test.src.task.strong.inferred_type_test;
 
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 43 matching lines @@
     expect(g.type.toString(), '() → Future<int>');
   }
 
   void test_asyncClosureReturnType_future() {
     var mainUnit = checkFile('var f = () async => 0;');
     var f = mainUnit.topLevelVariables[0];
     expect(f.name, 'f');
     expect(f.type.toString(), '() → Future<int>');
   }
 
+  void test_asyncClosureReturnType_futureOr() {
+    var mainUnit = checkFile('''
+import 'dart:async';
+FutureOr<int> futureOrInt = null;
+var f = () => futureOrInt;
+var g = () async => futureOrInt;
+''');
+    var futureOrInt = mainUnit.topLevelVariables[0];
+    expect(futureOrInt.name, 'futureOrInt');
+    expect(futureOrInt.type.toString(), 'FutureOr<int>');
+    var f = mainUnit.topLevelVariables[1];
+    expect(f.name, 'f');
+    expect(f.type.toString(), '() → FutureOr<int>');
+    var g = mainUnit.topLevelVariables[2];
+    expect(g.name, 'g');
+    expect(g.type.toString(), '() → Future<int>');
+  }
+
   void test_blockBodiedLambdas_async_allReturnsAreFutures() {
     if (!mayCheckTypesOfLocals) {
       return;
     }
     var mainUnit = checkFile(r'''
 import 'dart:async';
 import 'dart:math' show Random;
 main() {
   var f = /*info:INFERRED_TYPE_CLOSURE*/() async {
     if (new Random().nextBool()) {
@@ skipping 1584 matching lines @@
     var mainUnit = checkFile('''
 class C {
   final x = y;
 }
 int get y => null;
 ''');
     var x = mainUnit.types[0].fields[0];
     expect(x.type.toString(), 'int');
   }
 
+  void test_futureOr_subtyping() {
+    checkFile(r'''
+import 'dart:async';
+void add(int x) {}
+add2(int y) {}
+main() {
+  Future<int> f;
+  var a = f.then(add);
+  var b = f.then(add2);
+}
+    ''');
+  }
+
   void test_futureThen() {
     String build({String declared, String downwards, String upwards}) => '''
 import 'dart:async';
 class MyFuture<T> implements Future<T> {
   MyFuture() {}
   MyFuture.value(T x) {}
   dynamic noSuchMethod(invocation);
   MyFuture<S> then<S>(FutureOr<S> f(T x), {Function onError}) => null;
 }
 
@@ skipping 170 matching lines @@
 main() {
   Future<int> base;
   var f = base.then(/*info:INFERRED_TYPE_CLOSURE,info:INFERRED_TYPE_CLOSURE*/(x) { return x == 0; });
   var g = base.then(/*info:INFERRED_TYPE_CLOSURE*/(x) => x == 0);
   Future<bool> b = f;
   b = g;
 }
     ''');
   }
 
-  void test_futureOr_subtyping() {
-    checkFile(r'''
-import 'dart:async';
-void add(int x) {}
-add2(int y) {}
-main() {
-  Future<int> f;
-  var a = f.then(add);
-  var b = f.then(add2);
-}
-    ''');
-  }
-
   void test_futureUnion_asyncConditional() {
     String build({String declared, String downwards, String upwards}) => '''
 import 'dart:async';
 class MyFuture<T> implements Future<T> {
   MyFuture() {}
   MyFuture.value(x) {}
   dynamic noSuchMethod(invocation);
   MyFuture<S> then<S>(FutureOr<S> f(T x), {Function onError}) => null;
 }
 
@@ skipping 3499 matching lines @@
   }
 
   void setUp() {
     helper.doSetUp();
   }
 
   void tearDown() {
     helper.doTearDown();
   }
 }