Handle multiline interpolated strings in line-based scanner.

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.
 
 library trydart.paste_test;
 
 import 'dart:html';
 import 'dart:async';
 
 import 'package:try/src/interaction_manager.dart' show
@@ skipping 13 matching lines @@
   '<span><p>//...</p>}</span>': '//...\n}',
   'someText': 'someText',
   '"\$"': '"<DIAGNOSTIC>\$</DIAGNOSTIC>"',
   '"\$\$"': '"<DIAGNOSTIC>\$</DIAGNOSTIC><DIAGNOSTIC>\$</DIAGNOSTIC>"',
   '"\$\$4"': '"<DIAGNOSTIC>\$</DIAGNOSTIC><DIAGNOSTIC>\$</DIAGNOSTIC>4"',
   '"\$\$4 "': '"<DIAGNOSTIC>\$</DIAGNOSTIC><DIAGNOSTIC>\$</DIAGNOSTIC>4 "',
   '1e': '<DIAGNOSTIC>1e</DIAGNOSTIC>',
   'r"""\n\n\'"""': 'r"""\n\n\'"""',
   '"': '<DIAGNOSTIC>"</DIAGNOSTIC>',
   '/**\n*/': '/**\n*/',
+
+  // The following case tests that single line strings can span multiple lines
+  // via ${}. The string is constructed so that it is possible to tell if the
+  // line-bases scanner (incorrectly) reverses the order of the string quotes
+  // in its state string. The example string is a complicated way of writing:
+  // '[[{{}: {}}]]'. See also
+  // tests/language/string_interpolation_newline_test.dart.
+  '"\${ [ "\${ [ \'\${ { \'\${\n{\n} }\' : {\n} } }\' ] }" ] }"':
+  '"\${ [ "\${ [ \'\${ { \'\${\n{\n} }\' : {\n} } }\' ] }" ] }"',
 };
 
 List<Node> queryDiagnosticNodes() {
   return mainEditorPane.querySelectorAll('a.diagnostic>span');
 }
 
 Future runTests() {
   Iterator<String> keys = tests.keys.iterator;
   keys.moveNext();
   mainEditorPane.innerHtml = keys.current;
@@ skipping 27 matching lines @@
 
   var interaction = new InteractionManager();
   mainEditorPane = new DivElement();
   document.body.append(mainEditorPane);
   observer = new MutationObserver(interaction.onMutation)
       ..observe(
           mainEditorPane, childList: true, characterData: true, subtree: true);
 
   asyncTest(runTests);
 }