add configurable exports test

Author: jakemac53

_test/build.dart2js.yaml

@@ -9,8 +9,8 @@ targets:
         generate_for:
           - web/main.dart
           - web/sub/main.dart
-          - test/config_specific_import_test.dart
-          - test/config_specific_import_test.dart.browser_test.dart
+          - test/configurable_uri_test.dart
+          - test/configurable_uri_test.dart.browser_test.dart
           - test/hello_world_test.dart
           - test/hello_world_test.dart.browser_test.dart
           - test/hello_world_deferred_test.dart
@@ -22,5 +22,5 @@ targets:
           - test/sub-dir/subdir_test.dart.browser_test.dart
       build_vm_compilers|entrypoint:
         generate_for:
-          - test/config_specific_import_test.dart.vm_test.dart
+          - test/configurable_uri_test.dart.vm_test.dart
           - test/help_test.dart.vm_test.dart

_test/build.yaml

@@ -5,8 +5,8 @@ targets:
         generate_for:
           - web/main.dart
           - web/sub/main.dart
-          - test/config_specific_import_test.dart
-          - test/config_specific_import_test.dart.browser_test.dart
+          - test/configurable_uri_test.dart
+          - test/configurable_uri_test.dart.browser_test.dart
           - test/hello_world_test.dart
           - test/hello_world_test.dart.browser_test.dart
           - test/hello_world_deferred_test.dart
@@ -18,5 +18,5 @@ targets:
           - test/sub-dir/subdir_test.dart.browser_test.dart
       build_vm_compilers|entrypoint:
         generate_for:
-          - test/config_specific_import_test.dart.vm_test.dart
+          - test/configurable_uri_test.dart.vm_test.dart
           - test/help_test.dart.vm_test.dart

_test/test/common/message_export.dart

@@ -0,0 +1,7 @@
+// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS 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.
+
+export 'message.dart'
+    if (dart.library.io) 'message_io.dart'
+    if (dart.library.html) 'message_html.dart';

_test/test/config_specific_import_test.dart _test/test/configurable_uri_test.dart

@@ -4,19 +4,30 @@
 
 import 'package:test/test.dart';
 
-// ignore: uri_does_not_exist
 import 'common/message.dart'
-    // ignore: uri_does_not_exist
     if (dart.library.io) 'common/message_io.dart'
-    // ignore: uri_does_not_exist
     if (dart.library.html) 'common/message_html.dart';
 
+import 'common/message_export.dart' as exported;
+
 main() {
-  test('Message matches expected', () {
-    if (1.0 is int) {
+  group('browser', () {
+    test('imports', () {
       expect(message, contains('Javascript'));
-    } else {
+    });
+
+    test('exports', () {
+      expect(exported.message, contains('Javascript'));
+    });
+  }, testOn: 'browser');
+
+  group('vm', () {
+    test('imports', () {
       expect(message, contains('VM'));
-    }
-  });
+    });
+
+    test('exports', () {
+      expect(exported.message, contains('VM'));
+    });
+  }, testOn: 'vm');
 }