Run pub tests against older versions of barback.

sdk/lib/_internal/pub/test/serve/supports_user_defined_lazy_transformers_test.dart

Index: sdk/lib/_internal/pub/test/serve/supports_user_defined_lazy_transformers_test.dart
diff --git a/sdk/lib/_internal/pub/test/serve/supports_user_defined_lazy_transformers_test.dart b/sdk/lib/_internal/pub/test/serve/supports_user_defined_lazy_transformers_test.dart
index 6a64b5de96ac2774a94d293ef406ac9465f5b72a..69859f47769da47b6e4d027c435b072c829d81f3 100644
--- a/sdk/lib/_internal/pub/test/serve/supports_user_defined_lazy_transformers_test.dart
+++ b/sdk/lib/_internal/pub/test/serve/supports_user_defined_lazy_transformers_test.dart
@@ -10,30 +10,32 @@ import 'utils.dart';
 
 main() {
   initConfig();
-  integration("supports a user-defined lazy transformer", () {
-    d.dir(appPath, [
-      d.pubspec({
-        "name": "myapp",
-        "transformers": ["myapp/src/transformer"]
-      }),
-      d.dir("lib", [d.dir("src", [
-        d.file("transformer.dart", LAZY_TRANSFORMER)
-      ])]),
-      d.dir("web", [
-        d.file("foo.txt", "foo")
-      ])
-    ]).create();
+  withBarbackVersions("any", () {
+    integration("supports a user-defined lazy transformer", () {
+      d.dir(appPath, [
+        d.pubspec({
+          "name": "myapp",
+          "transformers": ["myapp/src/transformer"]
+        }),
+        d.dir("lib", [d.dir("src", [
+          d.file("transformer.dart", LAZY_TRANSFORMER)
+        ])]),
+        d.dir("web", [
+          d.file("foo.txt", "foo")
+        ])
+      ]).create();
 
-    createLockFile('myapp', pkg: ['barback']);
+      createLockFile('myapp', pkg: ['barback']);
 
-    var server = pubServe();
-    // The build should complete without the transformer logging anything.
-    server.stdout.expect('Build completed successfully');
+      var server = pubServe();
+      // The build should complete without the transformer logging anything.
+      server.stdout.expect('Build completed successfully');
 
-    requestShouldSucceed("foo.out", "foo.out");
-    server.stdout.expect(emitsLines(
-        '[Info from LazyRewrite]:\n'
-        'Rewriting myapp|web/foo.txt.'));
-    endPubServe();
+      requestShouldSucceed("foo.out", "foo.out");
+      server.stdout.expect(emitsLines(
+          '[Info from LazyRewrite]:\n'
+          'Rewriting myapp|web/foo.txt.'));
+      endPubServe();
+    });
   });
 }