incremental improvement to top level code completion results

pkg/analysis_services/test/completion/completion_computer_test.dart

 // Copyright (c) 2014, 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.services.completion.suggestion;
 
+import 'dart:async';
+
 import 'package:analysis_services/completion/completion_computer.dart';
 import 'package:analysis_testing/reflective_tests.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:unittest/unittest.dart';
 
 import 'completion_test_util.dart';
-import 'dart:async';
 
 main() {
   groupSep = ' | ';
   runReflectiveTests(CompletionManagerTest);
   runReflectiveTests(DartCompletionManagerTest);
 }
 
 @ReflectiveTestCase()
 class CompletionManagerTest extends AbstractCompletionTest {
 
   test_dart() {
     Source source = addSource('/does/not/exist.dart', '');
-    var manager = CompletionManager.create(source, 0, null);
+    var manager = CompletionManager.create(context, source, 0, null);
     expect(manager.runtimeType, DartCompletionManager);
   }
 
   test_html() {
     Source source = addSource('/does/not/exist.html', '');
-    var manager = CompletionManager.create(source, 0, null);
+    var manager = CompletionManager.create(context, source, 0, null);
+    expect(manager.runtimeType, NoOpCompletionManager);
+  }
+
+  test_null_context() {
+    Source source = addSource('/does/not/exist.dart', '');
+    var manager = CompletionManager.create(null, source, 0, null);
     expect(manager.runtimeType, NoOpCompletionManager);
   }
 
   test_other() {
     Source source = addSource('/does/not/exist.foo', '');
-    var manager = CompletionManager.create(source, 0, null);
+    var manager = CompletionManager.create(context, source, 0, null);
     expect(manager.runtimeType, NoOpCompletionManager);
   }
 }
 
 @ReflectiveTestCase()
 class DartCompletionManagerTest extends AbstractCompletionTest {
 
   /// Assert that the list contains exactly one of the given type
   void assertContainsType(List computers, Type type) {
     int count = 0;
     computers.forEach((c) {
       if (c.runtimeType == type) {
         ++count;
       }
     });
     if (count != 1) {
       var msg = new StringBuffer();
       msg.writeln('Expected $type, but found:');
       computers.forEach((c) {
         msg.writeln('  ${c.runtimeType}');
       });
       fail(msg.toString());
     }
   }
 
   test_topLevel() {
     Source source = addSource('/does/not/exist.dart', '');
-    var manager = new DartCompletionManager(source, 0, searchEngine);
+    var manager = new DartCompletionManager(context, source, 0, searchEngine);
     bool anyResult;
     manager.results().forEach((_) {
       anyResult = true;
     });
     return new Future.delayed(Duration.ZERO, () {
       expect(anyResult, isTrue);
     });
   }
 }