Expression extractor transformer URI improvements

- Adding support for resolving 'packages/' uris (previously only handled '/packages/') from annotation templateUris.
- Adding support for /packages/ uris to the html_files transformer parameter for referencing package-relative URIs.
- Generating warnings for not-found files rather than build errors.

Closes #879

Author: Pete Blois

lib/tools/transformer/expression_generator.dart

@@ -77,7 +77,8 @@ class ExpressionGenerator extends Transformer with ResolverTransformer {
 
     var controller = new StreamController<String>();
     var assets = options.htmlFiles
-        .map((path) => new AssetId(id.package, path))
+        .map((path) => _uriToAssetId(path, transform))
+        .where((id) => id != null)
         .toList();
 
     // Get all of the contents of templates in @NgComponent(templateUrl:'...')
@@ -95,7 +96,10 @@ class ExpressionGenerator extends Transformer with ResolverTransformer {
         // Add any manually specified HTML files.
         assets.map((id) => transform.readInputAsString(id))
             .map((future) =>
-                future.then(controller.add).catchError(controller.addError))
+                future.then(controller.add).catchError((e) {
+                  transform.logger.warning('Unable to find $id from html_files '
+                      'in pubspec.yaml.');
+                }))
         ).then((_) {
           controller.close();
         });
@@ -104,6 +108,19 @@ class ExpressionGenerator extends Transformer with ResolverTransformer {
     return controller.stream;
   }
 
+  AssetId _uriToAssetId(String uri, Transform transform) {
+    if (path.url.isAbsolute(uri)) {
+      var parts = path.url.split(uri);
+      if (parts[1] == 'packages') {
+        var pkgPath = path.url.join('lib', path.url.joinAll(parts.skip(3)));
+        return new AssetId(parts[2], pkgPath);
+      }
+      transform.logger.warning('Cannot cache non-package absolute URIs. $uri');
+      return null;
+    }
+    return new AssetId(transform.primaryInput.id.package, uri);
+  }
+
   /// Finds any HTML files referencing the primary input of the transform.
   Future<AssetId> _findHtmlEntry(Transform transform) {
     var id = transform.primaryInput.id;

lib/tools/transformer/referenced_uris.dart

@@ -190,11 +190,10 @@ class _Processor {
 
   Future<_CacheEntry> cacheEntry(_CacheEntry entry) {
     return transform.readInputAsString(entry.assetId).then((contents) {
-      if (contents == null) {
-        warn('Unable to find ${entry.uri} at ${entry.assetId}', entry.element);
-      }
       entry.contents = contents;
       return entry;
+    }, onError: (e) {
+      warn('Unable to find ${entry.uri} at ${entry.assetId}', entry.element);
     });
   }
 
@@ -221,6 +220,10 @@ class _Processor {
     templateUriRewrites.forEach((regexp, replacement) {
       uri = uri.replaceFirst(regexp, replacement);
     });
+    // Normalize packages/ uri's to be /packages/
+    if (uri.startsWith('packages/')) {
+      uri = '/' + uri;
+    }
     return uri;
   }
 

test/tools/transformer/expression_generator_spec.dart

@@ -71,21 +71,29 @@ main() {
                     selector: 'my-component')
                 class FooComponent {}
 
+                @NgComponent(
+                    templateUrl: 'packages/b/bar.html',
+                    selector: 'my-component')
+                class BarComponent {}
+
                 main() {}
                 ''',
             'a|lib/foo.html': '''
                 <div>{{template.contents}}</div>''',
+            'b|lib/bar.html': '''
+                <div>{{bar}}</div>''',
             'a|web/index.html': '''
                 <script src='main.dart' type='application/dart'></script>''',
             'angular|lib/angular.dart': libAngular,
           },
-          getters: ['template', 'contents'],
-          setters: ['template', 'contents'],
+          getters: ['template', 'contents', 'bar'],
+          setters: ['template', 'contents', 'bar'],
           symbols: []);
     });
 
     it('should apply additional HTML files', () {
       htmlFiles.add('web/dummy.html');
+      htmlFiles.add('/packages/b/bar.html');
       return generates(phases,
           inputs: {
             'a|web/main.dart': '''
@@ -95,24 +103,54 @@ main() {
                 ''',
             'a|web/dummy.html': '''
                 <div>{{contents}}</div>''',
+            'b|lib/bar.html': '''
+                <div>{{bar}}</div>''',
             'a|web/index.html': '''
                 <script src='main.dart' type='application/dart'></script>''',
             'angular|lib/angular.dart': libAngular,
           },
-          getters: ['contents'],
-          setters: ['contents'],
+          getters: ['contents', 'bar'],
+          setters: ['contents', 'bar'],
           symbols: []).whenComplete(() {
             htmlFiles.clear();
           });
     });
+
+    it('should warn on not-found HTML files', () {
+      htmlFiles.add('web/not-found.html');
+      return generates(phases,
+          inputs: {
+            'a|web/main.dart': '''
+                import 'package:angular/angular.dart';
+
+                main() {}
+
+                @NgComponent(
+                    templateUrl: 'packages/b/not-found.html',
+                    selector: 'my-component')
+                class BarComponent {}
+                ''',
+            'a|web/index.html': '''
+                <script src='main.dart' type='application/dart'></script>''',
+            'angular|lib/angular.dart': libAngular,
+          },
+          messages: [
+            'warning: Unable to find /packages/b/not-found.html at '
+                'b|lib/not-found.html (web/main.dart 4 16)',
+            'warning: Unable to find a|web/main.dart from html_files in '
+                'pubspec.yaml.',
+          ]).whenComplete(() {
+            htmlFiles.clear();
+          });
+    });
   });
 }
 
 Future generates(List<List<Transformer>> phases,
     { Map<String, String> inputs,
-      List<String> getters,
-      List<String> setters,
-      List<String> symbols,
+      List<String> getters: const [],
+      List<String> setters: const [],
+      List<String> symbols: const [],
       Iterable<String> messages: const []}) {
 
   var buffer = new StringBuffer();