Issue 24566. Main AnalysisContext.getLibrariesContaining() should work also for SDK sources.

pkg/analyzer/test/src/context/context_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.src.context.context_test;
 
 import 'dart:async';
 
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/cancelable_future.dart';
@@ skipping 1191 matching lines @@
     // prepare "Stream" ClassElement
     ClassElement streamElement;
     {
       CompilationUnitElement testUnit = testLibrary.definingCompilationUnit;
       InterfaceType streamType = testUnit.topLevelVariables[0].type;
       streamElement = streamType.element;
     }
     // must be from SDK context
     AnalysisContext sdkContext = context.sourceFactory.dartSdk.context;
     expect(sdkContext, streamElement.context);
-    // must be in the "async" library
     Source intSource = streamElement.source;
-    List<Source> coreLibraries = sdkContext.getLibrariesContaining(intSource);
-    expect(coreLibraries, hasLength(1));
-    Source coreSource = coreLibraries[0];
-    expect(coreSource.isInSystemLibrary, isTrue);
-    expect(coreSource.shortName, 'async.dart');
+    // must be in the "async" library - SDK context
+    {
+      List<Source> coreLibraries = sdkContext.getLibrariesContaining(intSource);
+      expect(coreLibraries, hasLength(1));
+      Source coreSource = coreLibraries[0];
+      expect(coreSource.isInSystemLibrary, isTrue);
+      expect(coreSource.shortName, 'async.dart');
+    }
+    // must be in the "async" library - main context
+    {
+      List<Source> coreLibraries = context.getLibrariesContaining(intSource);
+      expect(coreLibraries, hasLength(1));
+      Source coreSource = coreLibraries[0];
+      expect(coreSource.isInSystemLibrary, isTrue);
+      expect(coreSource.shortName, 'async.dart');
+    }
   }
 
   void test_getLineInfo() {
     Source source = addSource(
         "/test.dart",
         r'''
 library lib;
 
 main() {}''');
     LineInfo info = context.getLineInfo(source);
@@ skipping 1313 matching lines @@
   }
 }
 
 class _AnalysisContextImplTest_test_applyChanges_removeContainer
     implements SourceContainer {
   Source libB;
   _AnalysisContextImplTest_test_applyChanges_removeContainer(this.libB);
   @override
   bool contains(Source source) => source == libB;
 }