JSHint removed from CodeMirror in 4.9.3

CodeMirror was introduced to WordPress 4.9 for an improved code editing experience. For JavaScriptJavaScript JavaScript or JS is an object-oriented computer programming language commonly used to create interactive effects within web browsers. WordPress makes extensive use of JS for a better user experience. While PHP is executed on the server, JS executes within a user’s browser. https://www.javascript.com/. linting, CodeMirror uses JSHint which unfortunately includes some code that isn't compatible with the GPL. Therefore, in WordPress 4.9.3, we are removing JSHint and replacing it with esprima and a custom wrapper to provide some basic linting for JavaScript. This allows the code editor to show compilation errors, but not errors in formatting. 

If your code relies upon JSHint from coreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress., you should update that code to include a copy of JSHint.  Please note that as JSHint isn't currently GPLGPL GNU General Public License. Also see copyright license. compatible, it can not be distributed in the WordPress PluginPlugin A plugin is a piece of software containing a group of functions that can be added to a WordPress website. They can extend functionality or add new features to your WordPress websites. WordPress plugins are written in the PHP programming language and integrate seamlessly with WordPress. These can be free in the WordPress.org Plugin Directory https://wordpress.org/plugins/ or can be cost-based plugin from a third-party Repository. 

For more info, please see #42850.

#4-9, #4-9-3, #codemirror, #dev-notes, #jshint