How can I validate JSON using .NET libraries that do NOT accept single quoted string tokens?

Question

I would like to validate JSON coming from an external source. The JSON RFC specifically states, that all strings should be wrapped in double quotes and single quotes are not valid. However, both the built-in JavaScriptSerializer and Json.NET's JsonConvert.DeserializeObject accept single quoted strings as valid. Is there a way to tell them not to accept single quoted strings, or is there another library available that validates according to the RFC standard?

Example:

{
    "this": "is",
    "valid": "json"
}

{
    'this': 'is',
    'invalid': 'json',
    'but': 'parsed',
    'correctly': 'by',
    'both': 'parsers',
    'I': 'mentioned'
}

score 1 · Accepted Answer · edited May 23 '17 at 12:22

1

Please, see this topic, I think, there is something similar to your problem...

Sorry, I was not attentive enough. You might be searching for something like this:

private bool ValidateJson(string json)
        {
            using (var reader = new JsonTextReader(new StringReader(json)))
            {
                while (reader.Read())
                {
                    if (reader.QuoteChar == '\'')
                        return false;
                }
            }

            return true;
        }

Then, let's test this example:

[TestMethod]
    public void SingleQuoteJsonDeserialize()
    {
        var jsonSingle = "{'this': 'is', 'invalid': 'json', 'but': 'parsed', 'correctly': 'by', 'both': 'parsers', 'I': 'mentioned'}";
        var jsonDouble = "{\"this\": \"is\", \"valid\": \"json\"}";

        Assert.AreEqual(false, ValidateJson(jsonSingle));
        Assert.AreEqual(true, ValidateJson(jsonDouble));
    }

edited May 23 '17 at 12:22

Community

1
1

answered Jun 03 '16 at 15:13

Johnny Svarog

1,125
10
17

Well, that's pretty much the opposite of what I am trying to achieve, so alas of no help. I had already found that, but it is only used in serialization, not deserialization. – Christoph Herold Jun 04 '16 at 07:45
I've corrected the answer. Please, check it out... hope, it helps – Johnny Svarog Jun 06 '16 at 06:19
Bingo, that's what I was looking for. Thanks a lot for the solution! – Christoph Herold Jun 06 '16 at 20:43

How can I validate JSON using .NET libraries that do NOT accept single quoted string tokens?

1 Answers1