I wanted to be able to not only tidy my JSON objects, but also sort by property. I wanted to do this so I could unify my project.json and config.json files while working in .NET Core. Figuring out where people were adding keys, finding redundant things added to files, and so on… having a predictable order makes it all that much easier.

Up front, I’ll tell you this is a total hack. I got it to work as a user package (code in your User folder) but haven’t taken it as far as putting it into a repo or adding it to Package Control. That’s probably the next step. I just wanted to get this out there.

I’ll also say this is instructions for a Windows environment. The places you’ll have to adjust for Linux should be obvious, but I don’t have guidance or instructions to help you. Sorry.

First, install the External Command package. This is a great general-purpose package for setting up external commands and pushing Sublime Text buffers through. Select some text and have that text passed to an external shell command on stdin. (No selection? It runs the whole file.)

Next, create a folder called SortJson in your User package folder. This is where we’ll put the contents of the user module.

If you don’t have Node installed… why not? Really, though, if you don’t, go get it and install it. We need it because we use the Node json-stable-stringify package to do the work.

Drop to a command prompt in the SortJson folder and install the json-stable-stringify module.

npm install json-stable-stringify

You should get a node_modules folder under that SortJson folder and inside you’ll have json-stable-stringify (and maybe dependencies, but that’s fine).

Now we need a little script to take the contents of stdin and pass it through json-stable-stringify.

Create a script called sort-json.js in the SortJson folder. In that script, put this:

var stringify = require('json-stable-stringify');
var opts = {
    "space": 2
};

var stdin = process.stdin,
    stdout = process.stdout,
    inputChunks = [];

stdin.resume();
stdin.setEncoding('utf8');

stdin.on('data', function (chunk) {
    inputChunks.push(chunk);
});

stdin.on('end', function () {
    var inputJSON = inputChunks.join(""),
        parsedData = JSON.parse(inputJSON),
        outputJSON = stringify(parsedData, opts);
    stdout.write(outputJSON);
    stdout.write('\n');
});

Unfortunately, the External Command package doesn’t let you set a working directory, so you can’t just fire up Node and run the sort-json.js directly. We have to create a little batch file that helps our script find the json-stable-stringify module at runtime.

Create a batch script called sort-json.cmd in the SortJson folder. In that script, put this:

@SETLOCAL
@SET NODE_MODULES=%~dp0node_modules
@node "%~dp0sort-json.js" %*

That temporarily adds the SortJson\node_modules folder to the NODE_MODULES environment variable before running the sort-json.js script.

The last thing you need is a tie to the Sublime Text command palette so you can run the command to sort JSON.

Create a file called sort-json.sublime-commands in the SortJson folder. In that file, put this:

[
    {
        "caption": "JSON: Sort Object",
        "command": "filter_through_command",
        "args": { "cmdline": "\"%APPDATA%\\Sublime Text 3\\Packages\\User\\SortJson\\sort-json.cmd\"" }
    }
]

You’ll have to restart Sublime, but when you do you’ll see a command in the palette “JSON: Sort Object”. Load up a file with a JSON object and run that command. You should get a sorted JSON object.

I try to pair this with the JsFormat package (for JSBeautify integration) as well as SublimeLinter-json (for linting/error checking), both of which are in Package Control. If you want to tweak the formatting that comes out of the sort directly, the opts variable you see at the top of sort-json.js are the options used by json-stable-stringify.