Package map source factory support.

pkg/analyzer/lib/src/generated/source.dart

Index: pkg/analyzer/lib/src/generated/source.dart
diff --git a/pkg/analyzer/lib/src/generated/source.dart b/pkg/analyzer/lib/src/generated/source.dart
index 4900cf687fd5f68a6be3a52acc51f9d5c249b6d0..6350e89ce5d36bcea57ce9f69773e3d1c1b486e7 100644
--- a/pkg/analyzer/lib/src/generated/source.dart
+++ b/pkg/analyzer/lib/src/generated/source.dart
@@ -8,11 +8,14 @@
 library engine.source;
 
 import 'dart:collection';
+import 'dart:io';
 import "dart:math" as math;
 
 import 'package:analyzer/file_system/file_system.dart';
+import 'package:analyzer/file_system/physical_file_system.dart';
 import 'package:analyzer/source/package_map_resolver.dart';
 import 'package:analyzer/task/model.dart';
+import 'package:package_config/packages.dart';
 import 'package:path/path.dart' as pathos;
 
 import 'engine.dart';
@@ -575,6 +578,12 @@ class SourceFactory {
   AnalysisContext context;
 
   /**
+   * URI processor used to find mappings for `package:` URIs found in a `.packages` config
+   * file.
+   */
+  final Packages _packages;
+
+  /**
    * The resolvers used to resolve absolute URI's.
    */
   final List<UriResolver> _resolvers;
@@ -585,11 +594,10 @@ class SourceFactory {
   LocalSourcePredicate _localSourcePredicate = LocalSourcePredicate.NOT_SDK;
 
   /**
-   * Initialize a newly created source factory.
-   *
-   * @param resolvers the resolvers used to resolve absolute URI's
+   * Initialize a newly created source factory with the given absolute URI [resolvers] and
+   * optional [packages] resolution helper.
    */
-  SourceFactory(this._resolvers);
+  SourceFactory(this._resolvers, [this._packages = Packages.noPackages]);
 
   /**
    * Return the [DartSdk] associated with this [SourceFactory], or `null` if there
@@ -620,6 +628,20 @@ class SourceFactory {
   /// A table mapping package names to paths of directories containing
   /// the package (or [null] if there is no registered package URI resolver).
   Map<String, List<Folder>> get packageMap {
+    // Start by looking in .packages.
+    if (_packages != Packages.noPackages) {
+      Map<String, List<Folder>> packageMap = <String, List<Folder>>{};
+      _packages.asMap().forEach((String name, Uri uri) {
+        if (uri.scheme == 'file' || uri.scheme == '' /* unspecified */) {
+          packageMap[name] = <Folder>[
+            PhysicalResourceProvider.INSTANCE.getFolder(uri.toFilePath())
+          ];
+        }
+      });
+      return packageMap;
+    }
+
+    // Default to the PackageMapUriResolver.
     PackageMapUriResolver resolver = _resolvers.firstWhere(
         (r) => r is PackageMapUriResolver, orElse: () => null);
     return resolver != null ? resolver.packageMap : null;
@@ -727,13 +749,41 @@ class SourceFactory {
    * @return the absolute URI representing the given source
    */
   Uri restoreUri(Source source) {
+    // First see if a resolver can restore the URI.
     for (UriResolver resolver in _resolvers) {
       Uri uri = resolver.restoreAbsolute(source);
       if (uri != null) {
+        // Now see if there's a package mapping.
+        Uri packageMappedUri = _getPackageMapping(uri);
+        if (packageMappedUri != null) {
+          return packageMappedUri;
+        }
+        // Fall back to the resolver's computed URI.
         return uri;
       }
     }
-    return null;
+
+    // In case no resolver can restore the URI, default to a .packages look-up.
+    return _getPackageMapping(source.uri);
+  }
+
+  Uri _getPackageMapping(Uri uri) {
+    if (uri.scheme != 'file') {

[Brian Wilkerson, 2015/06/30 23:29:38]

I'm a little concerned that longer term we'll need to handle non-file uri's. But
I guess we can deal with that later. (Perhaps add a TODO to remind us.)

[pquitslund, 2015/06/30 23:46:05]

Right.  Added TODO.

+      return null;
+    }
+
+    String sourcePath = uri.toFilePath();
+    Uri packageUri;
+    _packages.asMap().forEach((String name, Uri uri) {
+      if (packageUri == null) {
+        String uriPath = uri.toFilePath();
+        if (sourcePath.startsWith(uriPath)) {
+          packageUri = Uri
+              .parse('package:$name/${sourcePath.substring(uriPath.length)}');
+        }
+      }
+    });
+    return packageUri;
   }
 
   /**
@@ -748,6 +798,14 @@ class SourceFactory {
    *           against the source object's URI
    */
   Source _internalResolveUri(Source containingSource, Uri containedUri) {
+    // Check .packages first.
+    if (containedUri.scheme == 'package') {
+      Uri packageUri = _packages.resolve(containedUri);
+      //TODO(pquitslund): package_config needs to be updated to set schemes for file URIs.
+      if (packageUri != null && packageUri.scheme == '') {
+        containedUri = new Uri.file(packageUri.toFilePath());
+      }
+    }
     if (!containedUri.isAbsolute) {
       if (containingSource == null) {
         throw new AnalysisException(