Inference through conditional expressions

test/checker/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.
 
 /// General type checking tests
 library dev_compiler.test.checker_test;
 
 import 'package:unittest/unittest.dart';
 
 import 'package:dev_compiler/src/testing.dart';
 
 import '../test_util.dart';
 
 void main() {
   configureTest();
 
+  test('ternary operator', () {
+    testChecker({
+      '/main.dart': '''
+        abstract class Comparable<T> {
+          int compareTo(T other);
+          static int compare(Comparable a, Comparable b) => a.compareTo(b);
+        }
+        typedef int Comparator<T>(T a, T b);
+
+        typedef bool _Predicate<T>(T value);
+
+        class SplayTreeMap<K, V> {
+          Comparator<K> _comparator;
+          _Predicate _validKey;
+
+          // Initializing _comparator needs a cast, since K may not always be
+          // Comparable.
+          // Initializing _validKey shouldn't need a cast.  Currently
+          // it requires inference to work because of dartbug.com/23381
+          SplayTreeMap([int compare(K key1, K key2),
+                        bool isValidKey(potentialKey)]) {
+            : _comparator = /*warning:DownCastComposite*/(compare == null) ? Comparable.compare : compare,
+              _validKey = /*info:InferredType should be pass*/(isValidKey != null) ? isValidKey : ((v) => true);
+          }
+        }
+        void main() {
+        }
+      '''
+    });
+  });
+
   test('dynamic invocation', () {
     testChecker({
       '/main.dart': '''
 
       class A {
         dynamic call(dynamic x) => x;
       }
       class B extends A {
         int call(int x) => x;
         double col(double x) => x;
@@ skipping 2855 matching lines @@
             f = bar as II2D;
             f = bar as DD2I;
             f = bar as DI2D;
             f = bar as ID2D;
             f = bar as DD2D;
           }
       '''
     });
   });
 }