How can I read JSON content with a comment with Json.NET?

Question

In order to install an external extension into Google Chrome browser, I try to update a Chrome external extension JSON file. Using Json.NET it seems to be easy:

string fileName = "..."; // Path to a Chrome external extension JSON file  string externalExtensionsJson = File.ReadAllText(fileName);  JObject externalExtensions = JObject.Parse(externalExtensionsJson); 

but I get a Newtonsoft.Json.JsonReaderException saying:

"Error parsing comment. Expected: *, got /. Path '', line 1, position 1." 

when calling JObject.Parse because this file contains:

// This JSON file will contain a list of extensions that will be included // in the installer.  { } 

And comments are not part of JSON (as seen in How do I add comments to Json.NET output?).

I know I can remove comments with a regular expression (Regular expression to remove JavaScript double slash (//) style comments), but I need to rewrite JSON into the file after modification and keeping comment can be a good thing.

Is there a way to read JSON content with comments without removing them and be able to rewrite them?

Answer 1

Json.NET only supports reading multi-line JavaScript comments, i.e. /* commment */

Update: Json.NET 6.0 supports single line comments

Answer 2

If you are stuck with JavaScriptSerializer (from the System.Web.Script.Serialization namespace), I have found that this works good enough...

private static string StripComments(string input) {     // JavaScriptSerializer doesn't accept commented-out JSON,     // so we'll strip them out ourselves;     // NOTE: for safety and simplicity, we only support comments on their own lines,     // not sharing lines with real JSON      input = Regex.Replace(input, @"^\s*//.*$", "", RegexOptions.Multiline);  // removes comments like this     input = Regex.Replace(input, @"^\s*/\*(\s|\S)*?\*/\s*$", "", RegexOptions.Multiline); /* comments like this */      return input; }