Fix exception in error processing; implement mapUri

pkg/analysis_server/lib/src/domain_execution.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.execution;
 
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/protocol.dart';
 import 'dart:collection';
@@ skipping 85 matching lines @@
     }
     AnalysisContext context = server.getAnalysisContext(path);
     if (params.file != null) {
       if (params.uri != null) {
         return new Response.invalidParameter(
             request,
             'file',
             'Either file or uri must be provided, but not both');
       }
       Source source = server.getSource(path);
-      // TODO(brianwilkerson) Figure out how to perform the mapping.
-      String uri = '';
+      String uri = context.sourceFactory.restoreUri(source).toString();
       return new ExecutionMapUriResult(uri: uri).toResponse(request.id);
     } else if (params.uri != null) {
-      // TODO(brianwilkerson) Figure out how to perform the mapping.
-      String file = '';
+      Source source = context.sourceFactory.forUri(params.uri);
+      String file = source.fullName;
       return new ExecutionMapUriResult(file: file).toResponse(request.id);
     }
     return new Response.invalidParameter(
         request,
         'file',
         'Either file or uri must be provided');
   }
 
   /**
    * Implement the 'execution.setSubscriptions' request.
@@ skipping 79 matching lines @@
         new ExecutionLaunchDataParams(
             executables,
             dartToHtml,
             htmlToDart).toNotification());
   }
 
   List<String> getFullNames(List<Source> sources) {
     return sources.map((Source source) => source.fullName).toList();
   }
 }