Handle bad regexs in search.findTopLevelDeclarations.

pkg/analysis_server/lib/src/search/search_domain.dart

Index: pkg/analysis_server/lib/src/search/search_domain.dart
diff --git a/pkg/analysis_server/lib/src/search/search_domain.dart b/pkg/analysis_server/lib/src/search/search_domain.dart
index 4a0e1b7a4eed93d1bc69f3b069862cf01f2f5fa5..f72b2962b6a689af46cf3284283c9e94e8183af6 100644
--- a/pkg/analysis_server/lib/src/search/search_domain.dart
+++ b/pkg/analysis_server/lib/src/search/search_domain.dart
@@ -115,18 +115,28 @@ class SearchDomainHandler implements protocol.RequestHandler {
     _sendSearchNotification(searchId, true, matches.map(toResult));
   }
 
-  Future findTopLevelDeclarations(protocol.Request request) async {
+  void findTopLevelDeclarations(protocol.Request request) {

[Brian Wilkerson, 2016/07/13 23:42:37]

Removing the `async` makes this much harder to read. What was the motivation?

[scheglov, 2016/07/14 00:18:07]

We could use something like this instead.

    () async {
      await server.onAnalysisComplete;
      // respond
      String searchId = (_nextSearchId++).toString();
      _sendSearchResult(
          request, new protocol.SearchFindTopLevelDeclarationsResult(searchId));
      // search
      List<SearchMatch> matches =
          await searchEngine.searchTopLevelDeclarations(params.pattern);
      _sendSearchNotification(searchId, true, matches.map(toResult));
    }();

     var params =
         new protocol.SearchFindTopLevelDeclarationsParams.fromRequest(request);
-    await server.onAnalysisComplete;
-    // respond
-    String searchId = (_nextSearchId++).toString();
-    _sendSearchResult(
-        request, new protocol.SearchFindTopLevelDeclarationsResult(searchId));
-    // search
-    List<SearchMatch> matches =
-        await searchEngine.searchTopLevelDeclarations(params.pattern);
-    _sendSearchNotification(searchId, true, matches.map(toResult));
+    try {
+      new RegExp(params.pattern);
+    } on FormatException catch (exception) {
+      throw new protocol.RequestFailure(new protocol.Response.invalidParameter(
+          request, 'pattern', exception.message));
+    }
+
+    server.onAnalysisComplete.then((_) {
+      // respond
+      String searchId = (_nextSearchId++).toString();
+      _sendSearchResult(
+          request, new protocol.SearchFindTopLevelDeclarationsResult(searchId));
+      // search
+      searchEngine
+          .searchTopLevelDeclarations(params.pattern)
+          .then((List<SearchMatch> matches) {
+        _sendSearchNotification(searchId, true, matches.map(toResult));
+      });
+    });
   }
 
   /**