Don't double-escape in strings in the VM Service, and don't use \u0000 to determine the string lengt

runtime/vm/object_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/globals.h"
 
 #include "vm/assembler.h"
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart_api_impl.h"
@@ skipping 4092 matching lines @@
 
   cls = Object::dynamic_class();
   array = cls.fields();
   EXPECT(!array.IsNull());
   EXPECT(array.IsArray());
   array = cls.functions();
   EXPECT(!array.IsNull());
   EXPECT(array.IsArray());
 }
 
 

[turnidge, 2014/09/09 16:12:31]

Could you add a direct unit test for ToCStringTruncated somewhere in this file,
which exercises both the truncate and no-truncate case?

[rmacnak, 2014/09/09 21:00:23]

Added.

-TEST_CASE(ToUserCString) {
-  const char* kScriptChars =
-      "var simple = 'simple';\n"
-      "var escapes = 'stuff\\n\\r\\f\\b\\t\\v\\'\"\\$stuff';\n"
-      "var uescapes = 'stuff\\u0001\\u0002stuff';\n"
-      "var toolong = "
-      "'01234567890123456789012345678901234567890123456789howdy';\n"
-      "var toolong2 = "
-      "'0123456789012345678901234567890123\\t567890123456789howdy';\n"
-      "var toolong3 = "
-      "'012345678901234567890123456789\\u0001567890123456789howdy';\n";
-  Dart_Handle lib = TestCase::LoadTestScript(kScriptChars, NULL);
-  EXPECT_VALID(lib);
-
-  String& obj = String::Handle();
-  Dart_Handle result;
-
-  // Simple string.
-  result = Dart_GetField(lib, NewString("simple"));
-  EXPECT_VALID(result);
-  obj ^= Api::UnwrapHandle(result);
-  EXPECT_STREQ("\"simple\"", obj.ToUserCString(40));
-
-  // Escaped chars.
-  result = Dart_GetField(lib, NewString("escapes"));
-  EXPECT_VALID(result);
-  obj ^= Api::UnwrapHandle(result);
-  EXPECT_STREQ("\"stuff\\n\\r\\f\\b\\t\\v'\\\"\\$stuff\"",
-               obj.ToUserCString(40));
-
-  // U-escaped chars.
-  result = Dart_GetField(lib, NewString("uescapes"));
-  EXPECT_VALID(result);
-  obj ^= Api::UnwrapHandle(result);
-  EXPECT_STREQ("\"stuff\\u0001\\u0002stuff\"", obj.ToUserCString(40));
-
-  // Truncation.
-  result = Dart_GetField(lib, NewString("toolong"));
-  EXPECT_VALID(result);
-  obj ^= Api::UnwrapHandle(result);
-  EXPECT_STREQ("\"01234567890123456789012345678901234\"...",
-               obj.ToUserCString(40));
-
-  // Truncation, shorter.
-  result = Dart_GetField(lib, NewString("toolong"));
-  EXPECT_VALID(result);
-  obj ^= Api::UnwrapHandle(result);
-  EXPECT_STREQ("\"01234\"...", obj.ToUserCString(10));
-
-  // Truncation, limit is in escape.
-  result = Dart_GetField(lib, NewString("toolong2"));
-  EXPECT_VALID(result);
-  obj ^= Api::UnwrapHandle(result);
-  EXPECT_STREQ("\"0123456789012345678901234567890123\"...",
-               obj.ToUserCString(40));
-
-  // Truncation, limit is in u-escape
-  result = Dart_GetField(lib, NewString("toolong3"));
-  EXPECT_VALID(result);
-  obj ^= Api::UnwrapHandle(result);
-  EXPECT_STREQ("\"012345678901234567890123456789\"...",
-               obj.ToUserCString(40));
-}
-
-
 class ObjectAccumulator : public ObjectVisitor {
  public:
   explicit ObjectAccumulator(GrowableArray<Object*>* objects)
       : ObjectVisitor(Isolate::Current()), objects_(objects) {}
   virtual ~ObjectAccumulator() { }
   virtual void VisitObject(RawObject* obj) {
     // Free-list elements cannot even be wrapped in handles.
     if (obj->IsFreeListElement()) {
       return;
     }
@@ skipping 175 matching lines @@
     JSONStream js;
     const String& str = String::Handle(String::New("dw"));
     str.PrintJSON(&js, true);
     elideSubstring("classes", js.ToCString(), buffer);
     elideSubstring("objects", buffer, buffer);
     elideSubstring("_OneByteString@", buffer, buffer);
     EXPECT_STREQ(
         "{\"type\":\"@String\","
         "\"class\":{\"type\":\"@Class\",\"id\":\"\","
         "\"name\":\"_OneByteString\",\"vmName\":\"\"},"
-        "\"id\":\"\",\"valueAsString\":\"\\\"dw\\\"\"}",
+        "\"id\":\"\",\"valueAsString\":\"dw\","
+        "\"valueAsStringIsTruncated\":false}",

[turnidge, 2014/09/09 16:12:31]

Omit if false

         buffer);
   }
   // Array reference
   {
     JSONStream js;
     const Array& array = Array::Handle(Array::New(0));
     array.PrintJSON(&js, true);
     elideSubstring("classes", js.ToCString(), buffer);
     elideSubstring("objects", buffer, buffer);
     elideSubstring("_List@", buffer, buffer);
@@ skipping 152 matching lines @@
   EXPECT_VALID(h_result);
   Integer& result = Integer::Handle();
   result ^= Api::UnwrapHandle(h_result);
   String& foo = String::Handle(String::New("foo"));
   Integer& expected = Integer::Handle();
   expected ^= foo.HashCode();
   EXPECT(result.IsIdenticalTo(expected));
 }
 
 }  // namespace dart