Load instances of the same transformer from the same isolate.

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

Index: sdk/lib/_internal/pub/test/transformer/loads_different_configurations_from_the_same_isolate_test.dart
diff --git a/sdk/lib/_internal/pub/test/transformer/loads_different_configurations_from_the_same_isolate_test.dart b/sdk/lib/_internal/pub/test/transformer/loads_different_configurations_from_the_same_isolate_test.dart
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+++ b/sdk/lib/_internal/pub/test/transformer/loads_different_configurations_from_the_same_isolate_test.dart
@@ -0,0 +1,90 @@
+// Copyright (c) 2014, 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 '../descriptor.dart' as d;
+import '../test_pub.dart';
+import '../serve/utils.dart';
+
+main() {
+  initConfig();
+  withBarbackVersions("any", () {
+    integration("loads different configurations from the same isolate", () {
+      // If different configurations are loaded from different isolates, a
+      // transformer can end up being loaded twice. It's even possible for the
+      // second load to use code that's transformed by the first, which is
+      // really bad. This tests sets up such a scenario.
+      //
+      // The foo package has two self-transformers: foo/first and foo/second,
+      // loaded in that order. This means that *no instances of foo/first*
+      // should ever have their code transformed by foo/second.
+      //
+      // The myapp package also has a reference to foo/first. This reference has
+      // a different configuration than foo's, which means that if it's loaded
+      // in a separate isolate, it will be loaded after all of foo's
+      // transformers have run. This means that foo/first.dart will have been
+      // transformed by foo/first and foo/second, causing it to have different
+      // code than the previous instance. This tests asserts that that doesn't
+      // happen.
+
+      d.dir("foo", [
+        d.pubspec({
+          "name": "foo",
+          "version": "1.0.0",
+          "transformers": [
+            {"foo/first": {"addition": " in foo"}},
+            "foo/second"
+          ]
+        }),
+        d.dir("lib", [
+          d.file("first.dart", dartTransformer('foo/first')),
+          d.file("second.dart", dartTransformer('foo/second'))
+        ])
+      ]).create();
+
+      d.dir(appPath, [
+        d.pubspec({
+          "name": "myapp",
+          "transformers": [
+            {
+              "foo/first": {
+                "addition": " in myapp",
+                "\$include": "web/first.dart"
+              }
+            },
+            {"foo/second": {"\$include": "web/second.dart"}}
+          ],
+          "dependencies": {'foo': {'path': '../foo'}}
+        }),
+        d.dir("web", [
+          // This is transformed by foo/first. It's used to see which
+          // transformers ran on foo/first.
+          d.file("first.dart", 'const TOKEN = "myapp/first";'),
+
+          // This is transformed by foo/second. It's used to see which
+          // transformers ran on foo/second.
+          d.file("second.dart", 'const TOKEN = "myapp/second";')
+        ])
+      ]).create();
+
+      createLockFile('myapp', sandbox: ['foo'], pkg: ['barback']);
+
+      pubServe();
+
+      // The version of foo/first used on myapp should have myapp's
+      // configuration and shouldn't be transformed by foo/second.
+      requestShouldSucceed("first.dart",
+          'const TOKEN = "(myapp/first, foo/first in myapp)";');
+
+      // foo/second should be transformed by only foo/first.
+      requestShouldSucceed("second.dart",
+          'const TOKEN = "(myapp/second, (foo/second, foo/first in foo))";');
+
+      endPubServe();
+    });
+  });
+}