feat(transformers): Allow more complicated package uris

Allow /packages/ identifier to appear anywhere in a uri and parse the AssetId correctly.

lib/tools/transformer/referenced_uris.dart

@@ -37,6 +37,7 @@ class _Processor {
   static const String cacheAnnotationName =
     'angular.template_cache_annotation.NgTemplateCache';
   static const String componentAnnotationName = 'angular.core.annotation_src.Component';
+  static final RegExp pkgRegex = new RegExp(r'.*\/packages\/([^\/]*)(\/.*)');
 
   _Processor(this.transform, this.resolver, this.options, this.skipNonCached,
       this.templatesOnly, this.urlResolver) {
@@ -209,13 +210,13 @@ class _Processor {
       return null;
     }
     if (path.url.isAbsolute(uri)) {
-      var parts = path.posix.split(uri);
-      if (parts[1] == 'packages') {
-        var pkgPath = path.url.join('lib', path.url.joinAll(parts.skip(3)));
-        return new _CacheEntry(uri, reference, new AssetId(parts[2], pkgPath));
+      var match = pkgRegex.firstMatch(uri);
+      if (match == null) {
+        warn('Cannot cache non-package absolute URIs. $uri', reference);
+        return null;
       }
-      warn('Cannot cache non-package absolute URIs. $uri', reference);
-      return null;
+      var assetId = new AssetId(match.group(1), 'lib/${match.group(2)}');
+      return new _CacheEntry(uri, reference, assetId);
     }
     // Everything else is a resource in the web directory according to pub;
     // as all packages URIs were handled above. As specified in this

test/tools/transformer/template_cache_generator_spec.dart

@@ -185,6 +185,44 @@ main() {
             'angular|lib/template_cache.dart': libCacheAnnotation,
       });
     });
+
+    it('should cache complicated URLs', () {
+      return generates(setupPhases(),
+          inputs: {
+              'a|web/main.dart': '''
+                    import 'package:angular/angular.dart';
+                    import 'dir/foo.dart';
+
+                    // Packages can be anywhere in the uri.
+                    @Component(templateUrl: "/x/y/z/packages/a.b.c/test1.html",
+                        cssUrl: "/packages/b/test1.css")
+                    class A {}
+
+                    main() {}
+              ''',
+              'a|web/dir/foo.dart': '''
+                    import 'package:angular/angular.dart';
+
+                    // Packages may show up multiple times. Only the last value
+                    // will be an identifier. Deeper paths after packages work.
+                    @Component(
+                        templateUrl: "/a/packages/z/packages/a/dir/test2.html",
+                        cssUrl: "/packages/y/dir/dir2/dir3/test2.css")
+                    class B {}
+              ''',
+              'a.b.c|lib/test1.html': htmlContent1,
+              'a|lib/dir/test2.html': htmlContent2,
+              'angular|lib/angular.dart': libAngular,
+              'b|lib/test1.css': cssContent1,
+              'y|lib/dir/dir2/dir3/test2.css': cssContent2,
+          },
+          cacheContent: {
+              '/x/y/z/packages/a.b.c/test1.html': htmlContent1,
+              '/packages/b/test1.css': cssContent1,
+              '/a/packages/z/packages/a/dir/test2.html': htmlContent2,
+              '/packages/y/dir/dir2/dir3/test2.css': cssContent2,
+      });
+    });
   });
 }