Escape strings when writing to JSON.

runtime/vm/json_test.cc

 // Copyright (c) 2012, 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.
 
 #include "platform/assert.h"
 #include "platform/json.h"
 #include "vm/json_stream.h"
 #include "vm/unit_test.h"
 
 namespace dart {
@@ skipping 233 matching lines @@
   JSONStream js(&tb);
   js.OpenArray();
   js.PrintValue(Object::Handle(Object::null()));
   js.OpenObject();
   js.PrintProperty("object_key", Object::Handle(Object::null()));
   js.CloseArray();
   EXPECT_STREQ("[{\"type\":\"null\"},{\"object_key\":{\"type\":\"null\"}]",
                tb.buf());
 }
 
+TEST_CASE(JSON_JSONStream_EscapedString) {
+  TextBuffer tb(256);
+  JSONStream js(&tb);
+  js.PrintValue("Hel\"\"lo\r\n\t");
+  EXPECT_STREQ("\"Hel\\\"\\\"lo\\r\\n\\t\"", tb.buf());
+}
+
 
 }  // namespace dart