Hook for overriding the creation of a package resolver

pkg/analysis_server/lib/src/context_manager.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 context.directory.manager;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:core' hide Resource;
 
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/source/optimizing_pub_package_map_provider.dart';
+import 'package:analysis_server/uri/resolver_provider.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/instrumentation/instrumentation.dart';
 import 'package:analyzer/source/package_map_resolver.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/java_io.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/source_io.dart';
 import 'package:path/path.dart' as pathos;
 import 'package:watcher/watcher.dart';
 
@@ skipping 50 matching lines @@
    */
   Map<String, String> packageRoots = <String, String>{};
 
   /**
    * Same as [packageRoots], except that source folders have been normalized
    * and non-folders have been removed.
    */
   Map<String, String> normalizedPackageRoots = <String, String>{};
 
   /**
+   * A function that will return a [UriResolver] that can be used to resolve
+   * `package:` URI's within a given folder, or `null` if we should fall back
+   * to the standard URI resolver.
+   */
+  final ResolverProvider packageResolverProvider;
+
+  /**
    * Provider which is used to determine the mapping from package name to
    * package folder.
    */
   final OptimizingPubPackageMapProvider _packageMapProvider;
 
   /**
    * The instrumentation service used to report instrumentation data.
    */
   final InstrumentationService _instrumentationService;
 
-  ContextManager(this.resourceProvider, this._packageMapProvider,
-      this._instrumentationService) {
+  ContextManager(this.resourceProvider, this.packageResolverProvider,
+      this._packageMapProvider, this._instrumentationService) {
     pathContext = resourceProvider.pathContext;
   }
 
   /**
    * Create and return a new analysis context.
    */
   AnalysisContext addContext(Folder folder, UriResolver packageUriResolver);
 
   /**
    * Called when the set of files associated with a context have changed (or
@@ skipping 319 matching lines @@
           if (res is Folder) {
             packageMap[file.getName()] = <Folder>[res];
           }
         }
         return new PackageMapUriResolver(resourceProvider, packageMap);
       }
       //TODO(danrubel) remove this if it will never be called
       return new PackageUriResolver([packagesDir]);
     } else {
       beginComputePackageMap();
+      if (packageResolverProvider != null) {
+        UriResolver resolver = packageResolverProvider(folder);
+        if (resolver != null) {
+          return resolver;
+        }
+      }
       OptimizingPubPackageMapInfo packageMapInfo;
       ServerPerformanceStatistics.pub.makeCurrentWhile(() {
         packageMapInfo =
             _packageMapProvider.computePackageMap(folder, info.packageMapInfo);
       });
       endComputePackageMap();
       for (String dependencyPath in packageMapInfo.dependencies) {
         Resource resource = resourceProvider.getResource(dependencyPath);
         if (resource is File) {
           StreamSubscription<WatchEvent> subscription;
@@ skipping 395 matching lines @@
     return excludes(resource.path);
   }
 
   /**
    * Returns `true` if [path] is the pubspec file of this context.
    */
   bool isPubspec(String path) {
     return path == pubspecPath;
   }
 }