Don't loop forever on scanner errors.

dart/tests/try/paste_content_rewriting_test.dart

 // Copyright (c) 2014, 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.
 
 // SharedOptions=--package-root=sdk/lib/_internal/
 
 library trydart.paste_test;
 
 import 'dart:html';
 import 'dart:async';
 
 import '../../site/try/src/interaction_manager.dart' show
     InteractionManager;
 
 import '../../site/try/src/ui.dart' show
     mainEditorPane,
     observer;
 
 import '../../site/try/src/user_option.dart' show
     UserOption;
 
 import '../../pkg/expect/lib/expect.dart';
 import '../../pkg/async_helper/lib/async_helper.dart';
 
-main() {
+const Map<String, String> tests = const <String, String> {
+  '<span><p>//...</p>}</span>': '//...\n}\n',
+  'someText': 'someText\n',
+  '"\$"': '"\$"<DIAGNOSTIC>\n',
+  '"\$\$"': '"\$\$<DIAGNOSTIC>"<DIAGNOSTIC>\n',
+  '"\$\$4"': '"\$\$<DIAGNOSTIC>4<DIAGNOSTIC>"\n',
+  '"\$\$4 "': '"\$\$<DIAGNOSTIC>4<DIAGNOSTIC> "\n',
+};
+
+List<Node> queryDiagnosticNodes() {
+  return mainEditorPane.querySelectorAll('a.diagnostic>span');
+}
+
+Future runTests() {
+  Iterator<String> keys = tests.keys.iterator;
+  keys.moveNext();
+  mainEditorPane.innerHtml = keys.current;
+
+  Future makeFuture() => new Future(() {
+    String key = keys.current;
+    print('Checking $key');
+    queryDiagnosticNodes().forEach((Node node) {
+      node.replaceWith(new Text('<DIAGNOSTIC>'));
+      observer.takeRecords(); // Discard mutations.
+    });
+    Expect.stringEquals(tests[key], mainEditorPane.text);
+    if (keys.moveNext()) {
+      key = keys.current;
+      print('Setting $key');
+      mainEditorPane.innerHtml = key;
+      return makeFuture();
+    } else {
+      // Clear the DOM to work around a bug in test.dart.
+      document.body.nodes.clear();
+      return null;
+    }
+  });
+
+  return makeFuture();
+}
+
+void main() {
   UserOption.storage = {};
 
   var interaction = new InteractionManager();
   mainEditorPane = new DivElement();
   document.body.append(mainEditorPane);
   observer = new MutationObserver(interaction.onMutation)
-      ..observe(mainEditorPane, childList: true, characterData: true, subtree: true);
+      ..observe(
+          mainEditorPane, childList: true, characterData: true, subtree: true);

[ahe, 2014/03/26 12:45:05]

You missed this long line :-)

 
   mainEditorPane.innerHtml = "<span><p>//...</p>}</span>";
 
-  asyncTest(() => new Future(() {
-    print('Welcome to the future');
-    Expect.stringEquals('//...\n}\n', mainEditorPane.text);
-  }).then((_) {
-    mainEditorPane.innerHtml = 'someText';
-    return new Future(() {
-      Expect.stringEquals('someText\n', mainEditorPane.text);
-
-      // Clear the DOM to work around a bug in test.dart.
-      document.body.nodes.clear();
-    });
-  }));
+  asyncTest(runTests);
 }