JSCS now (since v1.8.0) supports changing the esprima (ast parser) to esprima-fb (Facebooks version of esprima that can parse JSX). This makes JSXCS as a standalone tool obsolete. Same functionality (and more) can be achieved with jscs by using the following command.

npm install jscs esprima-fb
jscs --esprima=esprima-fb

or

jscs --esprima="./node_module/esprima-fb"

or in your .jscsrc

"esprima": "esprima-fb"

Also include the following in your .jscsrc

"fileExtensions": [".js", ".jsx"]

Read this gist for more detailed instructions and information/background.

JSXCS

Wrapper around jscs to allow running jscs for JSX files.

How to install

npm install jsxcs -g

How to use

See jscs for guides.

Caveats

As jsxcs works by ignoring errors on lines that are generated by the JSX transformer, some errors with actual user made styling issues might get omitted.