Fix for resynthesizing with multiply defined names.

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 25 matching lines @@
 abstract class AbstractResynthesizeTest extends AbstractSingleUnitTest {
   Set<Source> otherLibrarySources = new Set<Source>();
 
   /**
    * Names of variables which have initializers that are not valid constants,
    * so they are not resynthesized.
    */
   Set<String> variablesWithNotConstInitializers = new Set<String>();
 
   /**
+   * Names that cannot be resolved, e.g. because of duplicate declaration.
+   */
+  Set<String> namesThatCannotBeResolved = new Set<String>();
+
+  /**
    * Tests may set this to `true` to indicate that a missing file at the time of
    * summary resynthesis shouldn't trigger an error.
    */
   bool allowMissingFiles = false;
 
   void addLibrary(String uri) {
     otherLibrarySources.add(context.sourceFactory.forUri(uri));
   }
 
   Source addLibrarySource(String filePath, String contents) {
@@ skipping 318 matching lines @@
     } else {
       expect(r, isNotNull, reason: desc);
       // ConstantAstCloner does not copy static types, and constant values
       // computer does not use static types. So, we don't set them during
       // resynthesis and should not check them here.
       if (o is ParenthesizedExpression) {
         // We don't resynthesize parenthesis, so just ignore it.
         compareConstAsts(r, o.expression, desc);
       } else if (o is SimpleIdentifier && r is SimpleIdentifier) {
         expect(r.name, o.name, reason: desc);
-        compareElements(r.staticElement, o.staticElement, desc);
+        if (namesThatCannotBeResolved.contains(r.name)) {
+          expect(r.staticElement, isNull);
+        } else {
+          compareElements(r.staticElement, o.staticElement, desc);
+        }
       } else if (o is PrefixedIdentifier && r is SimpleIdentifier) {
         // We don't resynthesize prefixed identifiers when the prefix refers to
         // a PrefixElement or a ClassElement.  We use simple identifiers with
         // correct elements.
         if (o.prefix.staticElement is PrefixElement ||
             o.prefix.staticElement is ClassElement) {
           compareConstAsts(r, o.identifier, desc);
         } else {
           fail('Prefix of type ${o.prefix.staticElement.runtimeType} should not'
               ' have been elided');
@@ skipping 3498 matching lines @@
 
   test_invalid_importPrefix_asTypeArgument() {
     checkLibrary('''
 import 'dart:async' as ppp;
 class C {
   List<ppp> v;
 }
 ''');
   }
 
+  test_invalid_nameConflict_imported() {
+    namesThatCannotBeResolved.add('V');
+    addLibrarySource('/a.dart', 'V() {}');
+    addLibrarySource('/b.dart', 'V() {}');
+    checkLibrary('''
+import 'a.dart';
+import 'b.dart';
+foo([p = V]) {}
+''');
+  }
+
+  test_invalid_nameConflict_imported_exported() {
+    namesThatCannotBeResolved.add('V');
+    addLibrarySource('/a.dart', 'V() {}');
+    addLibrarySource('/b.dart', 'V() {}');
+    addLibrarySource(
+        '/c.dart',
+        r'''
+export 'a.dart';
+export 'b.dart';
+''');
+    checkLibrary('''
+import 'c.dart';
+foo([p = V]) {}
+''');
+  }
+
+  test_invalid_nameConflict_local() {
+    namesThatCannotBeResolved.add('V');
+    checkLibrary('''
+foo([p = V]) {}
+V() {}
+var V;
+''');
+  }
+
   test_invalid_setterParameter_fieldFormalParameter() {
     checkLibrary('''
 class C {
   int foo;
   void set bar(this.foo) {}
 }
 ''');
   }
 
   test_invalid_setterParameter_fieldFormalParameter_self() {
@@ skipping 1242 matching lines @@
       fail('Unexpectedly tried to get unlinked summary for $uri');
     }
     return serializedUnit;
   }
 
   @override
   bool hasLibrarySummary(String uri) {
     return true;
   }
 }