Actual URI support for package URI resolution.

pkg/analyzer/lib/src/generated/source.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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.source;
 
 import 'dart:collection';
@@ skipping 91 matching lines @@
     }
   }
 }
 
 class CustomUriResolver extends UriResolver {
   final Map<String, String> _urlMappings;
 
   CustomUriResolver(this._urlMappings);
 
   @override
-  Source resolveAbsolute(Uri uri) {
+  Source resolveAbsolute(Uri uri, [Uri actualUri]) {
     String mapping = _urlMappings[uri.toString()];
     if (mapping == null) return null;
 
     Uri fileUri = new Uri.file(mapping);
     if (!fileUri.isAbsolute) return null;
 
     JavaFile javaFile = new JavaFile.fromUri(fileUri);
-    return new FileBasedSource(javaFile);
+    return new FileBasedSource(javaFile, actualUri);
   }
 }
 
 /**
  * Instances of the class `DartUriResolver` resolve `dart` URI's.
  */
 class DartUriResolver extends UriResolver {
   /**
    * The name of the `dart` scheme.
    */
@@ skipping 18 matching lines @@
   DartUriResolver(this._sdk);
 
   /**
    * Return the [DartSdk] against which URIs are to be resolved.
    *
    * @return the [DartSdk] against which URIs are to be resolved.
    */
   DartSdk get dartSdk => _sdk;
 
   @override
-  Source resolveAbsolute(Uri uri) {
+  Source resolveAbsolute(Uri uri, [Uri actualUri]) {
     if (!isDartUri(uri)) {
       return null;
     }
     return _sdk.mapDartUri(uri.toString());
   }
 
   /**
    * Return `true` if the given URI is a `dart-ext:` URI.
    *
    * @param uriContent the textual representation of the URI being tested
@@ skipping 637 matching lines @@
    *           against the source object's URI
    */
   Source _internalResolveUri(Source containingSource, Uri containedUri) {
     if (!containedUri.isAbsolute) {
       if (containingSource == null) {
         throw new AnalysisException(
             "Cannot resolve a relative URI without a containing source: $containedUri");
       }
       containedUri = containingSource.resolveRelativeUri(containedUri);
     }
-    // Now check .packages.
+
+    Uri uriToResolve = containedUri;
+    Uri actualUri = null;

[Brian Wilkerson, 2015/07/21 18:48:34]

I'm not convinced that it's ever necessary to pass in `null` rather than the
containedUri, and the code would be easier to read and maintain with fewer
variables. If there's a case I'm not thinking of, a comment explaining it would
be helpful; otherwise a TODO to explore cleaning up the code would be good.

[Paul Berry, 2015/07/21 19:39:27]

I agree--AFAIK, always passing containedUri to resolveAbsolute() should produce
correct results all the time.

[pquitslund, 2015/07/21 20:55:10]

Ok.  Fixed up!

+
+    // Check .packages and update target and actual URIs as appropriate.
     if (_packages != null && containedUri.scheme == 'package') {
       Uri packageUri =
           _packages.resolve(containedUri, notFound: (Uri packageUri) => null);
-      // Ensure scheme is set.
-      if (packageUri != null && packageUri.scheme == '') {
-        packageUri = packageUri.replace(scheme: 'file');
+
+      if (packageUri != null) {
+        // Ensure scheme is set.
+        if (packageUri.scheme == '') {
+          packageUri = packageUri.replace(scheme: 'file');
+        }
+        uriToResolve = packageUri;
+        actualUri = containedUri;
       }
-      containedUri = packageUri;
     }
+
     for (UriResolver resolver in _resolvers) {
-      Source result = resolver.resolveAbsolute(containedUri);
+      Source result = resolver.resolveAbsolute(uriToResolve, actualUri);
       if (result != null) {
         return result;
       }
     }
+
     return null;
   }
 }
 
 /**
  * The enumeration `SourceKind` defines the different kinds of sources that are known to the
  * analysis engine.
  */
 class SourceKind extends Enum<SourceKind> {
   /**
@@ skipping 212 matching lines @@
  * URI's for a source factory. Subclasses of this class are expected to resolve a single scheme of
  * absolute URI.
  */
 abstract class UriResolver {
   /**
    * Resolve the given absolute URI. Return a [Source] representing the file to which
    * it was resolved, whether or not the resulting source exists, or `null` if it could not be
    * resolved because the URI is invalid.
    *
    * @param uri the URI to be resolved
+   * @param actualUri the actual uri for this source

[Paul Berry, 2015/07/21 19:39:27]

We should document that the caller is allowed to pass null, in which case the
source that's created will have a URI of [uri].

[pquitslund, 2015/07/21 20:55:10]

Done.

    * @return a [Source] representing the file to which given URI was resolved
    */
-  Source resolveAbsolute(Uri uri);
+  Source resolveAbsolute(Uri uri, [Uri actualUri]);
 
   /**
    * Return an absolute URI that represents the given source, or `null` if a valid URI cannot
    * be computed.
    *
    * @param source the source to get URI for
    * @return the absolute URI representing the given source
    */
   Uri restoreAbsolute(Source source) => null;
 }