Issue 24612. Skip excluded folder during contexts creation.

pkg/analysis_server/test/context_manager_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.context.directory.manager;
 
 import 'dart:collection';
 
 import 'package:analysis_server/src/context_manager.dart';
 import 'package:analyzer/file_system/file_system.dart';
@@ skipping 919 matching lines @@
   void test_setRoots_newlyAddedFoldersGetProperPackageMap() {
     String packagePath = '/package/foo';
     Folder packageFolder = resourceProvider.newFolder(packagePath);
     packageMapProvider.packageMap = {
       'foo': [packageFolder]
     };
     manager.setRoots(<String>[projPath], <String>[], <String, String>{});
     _checkPackageMap(projPath, equals(packageMapProvider.packageMap));
   }
 
+  void test_setRoots_noContext_excludedFolder() {
+    // prepare paths
+    String project = '/project';
+    String excludedFolder = '$project/excluded';
+    String excludedPubspec = '$excludedFolder/pubspec.yaml';
+    // create files
+    resourceProvider.newFile(excludedPubspec, 'name: ignore-me');
+    // set "/project", and exclude "/project/excluded"
+    manager.setRoots(
+        <String>[project], <String>[excludedFolder], <String, String>{});
+    callbacks.assertContextPaths([project]);
+  }
+
   void test_setRoots_noContext_inDotFolder() {
     String pubspecPath = posix.join(projPath, '.pub', 'pubspec.yaml');
     resourceProvider.newFile(pubspecPath, 'name: test');
     manager.setRoots(<String>[projPath], <String>[], <String, String>{});
     // verify
     expect(callbacks.currentContextPaths, hasLength(1));
     expect(callbacks.currentContextPaths, contains(projPath));
     expect(callbacks.currentContextFilePaths[projPath], hasLength(0));
   }
 
@@ skipping 884 matching lines @@
 class TestUriResolver extends UriResolver {
   Map<Uri, Source> uriMap;
 
   TestUriResolver(this.uriMap);
 
   @override
   Source resolveAbsolute(Uri uri, [Uri actualUri]) {
     return uriMap[uri];
   }
 }