Fix an exception caused by incomplete input (issue 29687)

pkg/analyzer/test/src/summary/resynthesize_common.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 test.src.serialization.elements_test;
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/standard_resolution_map.dart';
 import 'package:analyzer/dart/constant/value.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 455 matching lines @@
         compareConstAsts(r, o.propertyName, desc);
       } else if (o is SuperExpression && r is SuperExpression) {
         // Nothing to compare.
       } else if (o is ThisExpression && r is ThisExpression) {
         // Nothing to compare.
       } else if (o is NullLiteral) {
         expect(r, new isInstanceOf<NullLiteral>(), reason: desc);
       } else if (o is BooleanLiteral && r is BooleanLiteral) {
         expect(r.value, o.value, reason: desc);
       } else if (o is IntegerLiteral && r is IntegerLiteral) {
-        expect(r.value, o.value, reason: desc);
+        expect(r.value ?? 0, o.value ?? 0, reason: desc);
       } else if (o is DoubleLiteral && r is DoubleLiteral) {
         if (r.value != null &&
             r.value.isNaN &&
             o.value != null &&
             o.value.isNaN) {
           // NaN is not comparable.
         } else {
           expect(r.value, o.value, reason: desc);
         }
       } else if (o is StringInterpolation && r is StringInterpolation) {
@@ skipping 2799 matching lines @@
           r'''
 class C {
   final dynamic f =
         $$invalidConstExpr$$/*location: null*/;
 }
 int foo() {}
 ''');
     }
   }
 
+  test_const_invalid_intLiteral() {
+    var library = checkLibrary(
+        r'''
+const int x = 0x;
+''',
+        allowErrors: true);
+    if (isStrongMode) {
+      checkElementText(
+          library,
+          r'''
+const int x = 0;
+''');
+    } else {
+      checkElementText(
+          library,
+          r'''
+const int x = 0;

[scheglov, 2017/05/30 17:25:18]

I don't think we do this for all the tests, but in this case strong mode and
spec mode expectations are the same, so we could remove "if" and just do the
same check.

[Brian Wilkerson, 2017/05/30 17:38:45]

Done

+''');
+    }
+  }
+
   test_const_invalid_topLevel() {
     variablesWithNotConstInitializers.add('v');
     var library = checkLibrary(
         r'''
 const v = 1 + foo();
 int foo() => 42;
 ''',
         allowErrors: true);
     if (isStrongMode) {
       checkElementText(
@@ skipping 11985 matching lines @@
       fail('Unexpectedly tried to get unlinked summary for $uri');
     }
     return serializedUnit;
   }
 
   @override
   bool hasLibrarySummary(String uri) {
     return true;
   }
 }