Properly print an error when failing to load a transformer.

[email protected]
BUG= http://dartbug.com/21490

Review URL: https://codereview.chromium.org//1106803002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@45414 260f80e4-7a28-3924-810f-c04153c831b5

Author: nex3

sdk/lib/_internal/pub/lib/src/barback/dependency_computer.dart

@@ -11,6 +11,7 @@ import '../dart.dart';
 import '../io.dart';
 import '../package.dart';
 import '../package_graph.dart';
+import '../pubspec.dart';
 import '../utils.dart';
 import 'cycle_exception.dart';
 import 'transformer_config.dart';
@@ -104,6 +105,17 @@ class DependencyComputer {
   /// loaded.
   Set<TransformerId> _transformersNeededByTransformer(TransformerId id) {
     if (id.isBuiltInTransformer) return new Set();
+
+    if (!_graph.packages.containsKey(id.package)) {
+      // Throw this here rather than during pubspec parsing because by the time
+      // we're here, we're sure that the package is actually transforming public
+      // assets and that being unable to load it will be a problem.
+      throw new PubspecException(
+          'Error loading transformer "$id": package "${id.package}" is not '
+              'a dependency.',
+          id.span);
+    }
+
     _loadPackageComputer(id.package);
     return _packageComputers[id.package]._transformersNeededByTransformer(id);
   }

sdk/lib/_internal/pub/test/transformer/fails_to_load_a_transform_from_a_deps_dev_dependency_test.dart

@@ -0,0 +1,50 @@
+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS d.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 pub_tests;
+
+import 'package:scheduled_test/scheduled_test.dart';
+
+import '../../lib/src/exit_codes.dart' as exit_codes;
+import '../descriptor.dart' as d;
+import '../test_pub.dart';
+import '../serve/utils.dart';
+
+main() {
+  initConfig();
+  withBarbackVersions("any", () {
+    integration("fails to load a transform from a non-dependency", () {
+      d.dir("bar", [
+        d.pubspec({
+          "name": "bar",
+          "version": "1.0.0",
+        }),
+        d.dir("lib", [
+          d.file("transformer.dart", dartTransformer('bar')),
+        ])
+      ]).create();
+
+      d.dir("foo", [
+        d.pubspec({
+          "name": "foo",
+          "version": "1.0.0",
+          "dev_dependencies": {"bar": {"path": "../bar"}},
+          "transformers": ["bar"]
+        })
+      ]).create();
+
+      d.dir(appPath, [
+        d.pubspec({
+          "name": "myapp",
+          "dependencies": {"foo": {"path": "../foo"}}
+        })
+      ]).create();
+
+      var pub = startPubServe();
+      pub.stderr.expect(contains('Error loading transformer "bar": package '
+          '"bar" is not a dependency.'));
+      pub.shouldExit(exit_codes.DATA);
+    });
+  });
+}