Don't make assumptions about source encoding in analysis server tests (TBR).

pkg/analysis_server/test/analysis_server_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.analysis_server;
 
 import 'dart:async';
 
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source_io.dart';
@@ skipping 67 matching lines @@
     context.results.add(new AnalysisResult([changeNoticeImpl], 0, 'myClass', 0)
         );
     context.results.add(new AnalysisResult(null, 0, null, 0));
     return pumpEventQueue().then((_) {
       expect(context.results, isEmpty);
       expect(channel.notificationsReceived, hasLength(2));
       expect(channel.notificationsReceived[0].event, equals('server.connected')
           );
       expect(channel.notificationsReceived[1].event, equals('context.errors'));
       expect(channel.notificationsReceived[1].params['source'], equals(
-          '102file:///foo.dart')); // Issue 18739
+          source.encoding));
       List<AnalysisError> errors =
           channel.notificationsReceived[1].params['errors'];
       expect(errors, hasLength(1));
       expect(errors[0], equals(analysisError));
     });
   }
 
   static Future addContextToWorkQueue_twice() {
     // The context should only be asked to perform its analysis task once.
     MockAnalysisContext_withPerformAnalysisTask context =
@@ skipping 65 matching lines @@
   @override
   Response handleRequest(Request request) {
     if (request.method == 'echo') {
       var response = new Response(request.id);
       response.setResult('echo', true);
       return response;
     }
     return null;
   }
 }