Return RequestErrorCode.NO_INDEX_GENERATED if no index.

pkg/analysis_server/test/domain_completion_test.dart

Index: pkg/analysis_server/test/domain_completion_test.dart
diff --git a/pkg/analysis_server/test/domain_completion_test.dart b/pkg/analysis_server/test/domain_completion_test.dart
index 21307d553142c03936547e54218b3fbc7fff7d4f..0444f8a34c9b7cafdfcc6d9e3b23fe014edd15ad 100644
--- a/pkg/analysis_server/test/domain_completion_test.dart
+++ b/pkg/analysis_server/test/domain_completion_test.dart
@@ -34,6 +34,7 @@ main() {
   groupSep = ' | ';
   runReflectiveTests(CompletionManagerTest);
   runReflectiveTests(CompletionTest);
+  runReflectiveTests(_NoSearchEngine);
 }
 
 @reflectiveTest
@@ -55,6 +56,11 @@ class CompletionManagerTest extends AbstractAnalysisTest {
         InstrumentationService.NULL_SERVICE);
   }
 
+  @override
+  Index createIndex() {
+    return createLocalMemoryIndex();
+  }
+
   void sendRequest(String path) {
     String id = (++requestCount).toString();
     request = new CompletionGetSuggestionsParams(path, 0).toRequest(id);
@@ -665,3 +671,27 @@ class Test_CompletionDomainHandler extends CompletionDomainHandler {
     return new MockCompletionManager(mockContext, source, searchEngine);
   }
 }
+
+@reflectiveTest
+class _NoSearchEngine extends AbstractAnalysisTest {
+  @override
+  void setUp() {
+    super.setUp();
+    createProject();
+    handler = new CompletionDomainHandler(server);
+  }
+
+  test_noSearchEngine() async {
+    addTestFile('''
+main() {
+  ^
+}
+    ''');
+    await waitForTasksFinished();
+      Request request =
+          new CompletionGetSuggestionsParams(testFile, 0).toRequest('0');
+      Response response = handler.handleRequest(request);
+      expect(response.error, isNotNull);
+      expect(response.error.code, RequestErrorCode.NO_INDEX_GENERATED);
+  }
+}