More tweaks in attempt to debug the reason of failing getNavigation() tests.

pkg/analysis_server/lib/src/domain_analysis.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 domain.analysis;
 
 import 'dart:async';
 import 'dart:core' hide Resource;
 
 import 'package:analysis_server/src/analysis_server.dart';
@@ skipping 100 matching lines @@
    */
   Response getNavigation(Request request) {
     var params = new AnalysisGetNavigationParams.fromRequest(request);
     String file = params.file;
     Future<AnalysisDoneReason> analysisFuture =
         server.onFileAnalysisComplete(file);
     if (analysisFuture == null) {
       return new Response.getNavigationInvalidFile(request);
     }
     analysisFuture.then((AnalysisDoneReason reason) {
-      switch (reason) {
-        case AnalysisDoneReason.COMPLETE:
-          print('AnalysisDoneReason.COMPLETE');
-          List<CompilationUnit> units =
-              server.getResolvedCompilationUnits(file);
-          print('units: $units');
-          if (units.isEmpty) {
-            server.sendResponse(new Response.getNavigationInvalidFile(request));
-          } else {
-            DartUnitNavigationComputer computer =
-                new DartUnitNavigationComputer();
-            _GetNavigationAstVisitor visitor = new _GetNavigationAstVisitor(
-                params.offset, params.offset + params.length, computer);
-            for (CompilationUnit unit in units) {
-              unit.accept(visitor);
+      print('  reason: $reason');
+      try {
+        switch (reason) {
+          case AnalysisDoneReason.COMPLETE:
+            print('  AnalysisDoneReason.COMPLETE');
+            List<CompilationUnit> units =
+                server.getResolvedCompilationUnits(file);
+            print('  units: $units');
+            if (units.isEmpty) {
+              server
+                  .sendResponse(new Response.getNavigationInvalidFile(request));
+            } else {
+              DartUnitNavigationComputer computer =
+                  new DartUnitNavigationComputer();
+              _GetNavigationAstVisitor visitor = new _GetNavigationAstVisitor(
+                  params.offset, params.offset + params.length, computer);
+              for (CompilationUnit unit in units) {
+                unit.accept(visitor);
+              }
+              server.sendResponse(new AnalysisGetNavigationResult(
+                      computer.files, computer.targets, computer.regions)
+                  .toResponse(request.id));
             }
-            server.sendResponse(new AnalysisGetNavigationResult(
-                    computer.files, computer.targets, computer.regions)
-                .toResponse(request.id));
-          }
-          break;
-        case AnalysisDoneReason.CONTEXT_REMOVED:
-          print('AnalysisDoneReason.CONTEXT_REMOVED');
-          // The active contexts have changed, so try again.
-          Response response = getNavigation(request);
-          if (response != Response.DELAYED_RESPONSE) {
-            server.sendResponse(response);
-          }
-          break;
+            break;
+          case AnalysisDoneReason.CONTEXT_REMOVED:
+            print('  AnalysisDoneReason.CONTEXT_REMOVED');
+            // The active contexts have changed, so try again.
+            Response response = getNavigation(request);
+            if (response != Response.DELAYED_RESPONSE) {
+              server.sendResponse(response);
+            }
+            break;
+        }
+      } on Exception catch (e, st) {
+        print('Exception1 in AnalysisDomainHandler.getNavigation()');
+        print(e);
+        print(st);
       }
     }).catchError((e, st) {
-      print('Exception in AnalysisDomainHandler.getNavigation()');
+      print('Exception2 in AnalysisDomainHandler.getNavigation()');
       print(e);
       print(st);
     });
     // delay response
     return Response.DELAYED_RESPONSE;
   }
 
   @override
   Response handleRequest(Request request) {
     try {
@@ skipping 155 matching lines @@
       return;
     }
     // The node starts or ends in the range.
     if (isInRange(node.offset) || isInRange(node.end)) {
       computer.compute(node);
       return;
     }
     super.visitNode(node);
   }
 }