Issue 27374. Include all configuration sources into REFERENCED_SOURCES.

pkg/analyzer/test/src/task/dart_test.dart

 // Copyright (c) 2015, 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 analyzer.test.src.task.dart_test;
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 3256 matching lines @@
     expect(import.configurations[1].uriSource.shortName, 'foo_html.dart');
 
     var exported = outputs[EXPORTED_LIBRARIES] as List<Source>;
     _assertContainsOnlyShortName(exported, 'bar_io.dart');
 
     var export = unit.directives[1] as ExportDirective;
     expect(export.uriSource.shortName, 'bar.dart');
     expect(export.selectedSource.shortName, 'bar_io.dart');
     expect(export.configurations[0].uriSource.shortName, 'bar_io.dart');
     expect(export.configurations[1].uriSource.shortName, 'bar_html.dart');
+
+    var refSources = outputs[REFERENCED_SOURCES] as List<Source>;
+    var refNames = refSources.map((source) => source.shortName).toList();
+    expect(refNames, contains('test.dart'));
+    expect(refNames, contains('foo.dart'));
+    expect(refNames, contains('foo_io.dart'));
+    expect(refNames, contains('foo_html.dart'));
+    expect(refNames, contains('bar.dart'));
+    expect(refNames, contains('bar_io.dart'));
+    expect(refNames, contains('bar_html.dart'));
   }
 
   test_perform_library_configurations_bool2() {
     context.declaredVariables.define('dart.library.html', 'true');
     newSource('/foo.dart', '');
     newSource('/foo_io.dart', '');
     newSource('/foo_html.dart', '');
     _performParseTask(r'''
 import 'foo.dart'
   if (dart.library.io) 'foo_io.dart'
@@ skipping 2373 matching lines @@
   /**
    * Fill [errorListener] with [result] errors in the current [task].
    */
   void _fillErrorListener(ResultDescriptor<List<AnalysisError>> result) {
     List<AnalysisError> errors = task.outputs[result] as List<AnalysisError>;
     expect(errors, isNotNull, reason: result.name);
     errorListener = new GatheringErrorListener();
     errorListener.addAll(errors);
   }
 }